/*
  Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.

  The MySQL Connector/J is licensed under the terms of the GPLv2
  <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most MySQL Connectors.
  There are special exceptions to the terms and conditions of the GPLv2 as it is applied to
  this software, see the FLOSS License Exception
  <http://www.mysql.com/about/legal/licensing/foss-exception.html>.

  This program is free software; you can redistribute it and/or modify it under the terms
  of the GNU General Public License as published by the Free Software Foundation; version 2
  of the License.

  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along with this
  program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth
  Floor, Boston, MA 02110-1301  USA
 */
package com.mysql.jdbc;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.util.List;

/**
 * DatabaseMetaData implementation that uses INFORMATION_SCHEMA available in
 * MySQL-5.0 and newer.
 * 
 * The majority of the queries in this code were built for Connector/OO.org by
 * Georg Richter (georg_at_mysql.com).
 */
public class DatabaseMetaDataUsingInfoSchema extends DatabaseMetaData {

	protected enum JDBC4FunctionConstant {
		// COLUMN_TYPE values
		FUNCTION_COLUMN_UNKNOWN, FUNCTION_COLUMN_IN, FUNCTION_COLUMN_INOUT, FUNCTION_COLUMN_OUT,
		FUNCTION_COLUMN_RETURN, FUNCTION_COLUMN_RESULT,
		// NULLABLE values
		FUNCTION_NO_NULLS, FUNCTION_NULLABLE, FUNCTION_NULLABLE_UNKNOWN;
	}
	
	private boolean hasReferentialConstraintsView;
	private final boolean hasParametersView;
	
	protected DatabaseMetaDataUsingInfoSchema(MySQLConnection connToSet,
			String databaseToSet) throws SQLException {
		super(connToSet, databaseToSet);
		
		this.hasReferentialConstraintsView = 
			this.conn.versionMeetsMinimum(5, 1, 10);
		
		ResultSet rs = null;
		
		try {
			rs = super.getTables("INFORMATION_SCHEMA", null, "PARAMETERS", new String[0]);
			
			this.hasParametersView = rs.next();
		} finally {
			if (rs != null) {
				rs.close();
			}
		}
	}

	protected ResultSet executeMetadataQuery(java.sql.PreparedStatement pStmt)
			throws SQLException {
		ResultSet rs = pStmt.executeQuery();
		((com.mysql.jdbc.ResultSetInternalMethods) rs).setOwningStatement(null);

		return rs;
	}

	/**
	 * Get a description of the access rights for a table's columns.
	 * <P>
	 * Only privileges matching the column name criteria are returned. They are
	 * ordered by COLUMN_NAME and PRIVILEGE.
	 * </p>
	 * <P>
	 * Each privilige description has the following columns:
	 * <OL>
	 * <li> <B>TABLE_CAT</B> String => table catalog (may be null) </li>
	 * <li> <B>TABLE_SCHEM</B> String => table schema (may be null) </li>
	 * <li> <B>TABLE_NAME</B> String => table name </li>
	 * <li> <B>COLUMN_NAME</B> String => column name </li>
	 * <li> <B>GRANTOR</B> => grantor of access (may be null) </li>
	 * <li> <B>GRANTEE</B> String => grantee of access </li>
	 * <li> <B>PRIVILEGE</B> String => name of access (SELECT, INSERT, UPDATE,
	 * REFRENCES, ...) </li>
	 * <li> <B>IS_GRANTABLE</B> String => "YES" if grantee is permitted to
	 * grant to others; "NO" if not; null if unknown </li>
	 * </ol>
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schema
	 *            a schema name; "" retrieves those without a schema
	 * @param table
	 *            a table name
	 * @param columnNamePattern
	 *            a column name pattern
	 * @return ResultSet each row is a column privilege description
	 * @throws SQLException
	 *             if a database access error occurs
	 * @see #getSearchStringEscape
	 */
	public java.sql.ResultSet getColumnPrivileges(String catalog,
			String schema, String table, String columnNamePattern)
			throws SQLException {
		if (columnNamePattern == null) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				columnNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Column name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}	
		}
		
		String sql = "SELECT TABLE_SCHEMA AS TABLE_CAT, NULL AS TABLE_SCHEM, TABLE_NAME,"
			 +"COLUMN_NAME, NULL AS GRANTOR, GRANTEE, PRIVILEGE_TYPE AS PRIVILEGE, IS_GRANTABLE FROM "
			 + "INFORMATION_SCHEMA.COLUMN_PRIVILEGES WHERE "
			 + "TABLE_SCHEMA LIKE ? AND "
			 + "TABLE_NAME =? AND COLUMN_NAME LIKE ? ORDER BY " 
			 + "COLUMN_NAME, PRIVILEGE_TYPE";
		
		java.sql.PreparedStatement pStmt = null;
		
		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			
			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, table);
			pStmt.setString(3, columnNamePattern);
			
			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(new Field[] {
					new Field("", "TABLE_CAT", Types.CHAR, 64),
					new Field("", "TABLE_SCHEM", Types.CHAR, 1),
					new Field("", "TABLE_NAME", Types.CHAR, 64),
					new Field("", "COLUMN_NAME", Types.CHAR, 64),
					new Field("", "GRANTOR", Types.CHAR, 77),
					new Field("", "GRANTEE", Types.CHAR, 77),
					new Field("", "PRIVILEGE", Types.CHAR, 64),
					new Field("", "IS_GRANTABLE", Types.CHAR, 3)});
			
			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Get a description of table columns available in a catalog.
	 * <P>
	 * Only column descriptions matching the catalog, schema, table and column
	 * name criteria are returned. They are ordered by TABLE_SCHEM, TABLE_NAME
	 * and ORDINAL_POSITION.
	 * </p>
	 * <P>
	 * Each column description has the following columns:
	 * <OL>
	 * <li> <B>TABLE_CAT</B> String => table catalog (may be null) </li>
	 * <li> <B>TABLE_SCHEM</B> String => table schema (may be null) </li>
	 * <li> <B>TABLE_NAME</B> String => table name </li>
	 * <li> <B>COLUMN_NAME</B> String => column name </li>
	 * <li> <B>DATA_TYPE</B> short => SQL type from java.sql.Types </li>
	 * <li> <B>TYPE_NAME</B> String => Data source dependent type name </li>
	 * <li> <B>COLUMN_SIZE</B> int => column size. For char or date types this
	 * is the maximum number of characters, for numeric or decimal types this is
	 * precision. </li>
	 * <li> <B>BUFFER_LENGTH</B> is not used. </li>
	 * <li> <B>DECIMAL_DIGITS</B> int => the number of fractional digits </li>
	 * <li> <B>NUM_PREC_RADIX</B> int => Radix (typically either 10 or 2) </li>
	 * <li> <B>NULLABLE</B> int => is NULL allowed?
	 * <UL>
	 * <li> columnNoNulls - might not allow NULL values </li>
	 * <li> columnNullable - definitely allows NULL values </li>
	 * <li> columnNullableUnknown - nullability unknown </li>
	 * </ul>
	 * </li>
	 * <li> <B>REMARKS</B> String => comment describing column (may be null)
	 * </li>
	 * <li> <B>COLUMN_DEF</B> String => default value (may be null) </li>
	 * <li> <B>SQL_DATA_TYPE</B> int => unused </li>
	 * <li> <B>SQL_DATETIME_SUB</B> int => unused </li>
	 * <li> <B>CHAR_OCTET_LENGTH</B> int => for char types the maximum number
	 * of bytes in the column </li>
	 * <li> <B>ORDINAL_POSITION</B> int => index of column in table (starting
	 * at 1) </li>
	 * <li> <B>IS_NULLABLE</B> String => "NO" means column definitely does not
	 * allow NULL values; "YES" means the column might allow NULL values. An
	 * empty string means nobody knows. </li>
	 * </ol>
	 * </p>
	 */
	public ResultSet getColumns(String catalog, String schemaPattern,
			String tableName, String columnNamePattern) throws SQLException {
		if (columnNamePattern == null) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				columnNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Column name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}
		}

		StringBuffer sqlBuf = new StringBuffer("SELECT "
				+ "TABLE_SCHEMA AS TABLE_CAT, " + "NULL AS TABLE_SCHEM,"
				+ "TABLE_NAME," + "COLUMN_NAME,");
		MysqlDefs.appendJdbcTypeMappingQuery(sqlBuf, "DATA_TYPE");

		sqlBuf.append(" AS DATA_TYPE, ");

		if (conn.getCapitalizeTypeNames()) {
			sqlBuf.append("UPPER(CASE WHEN LOCATE('unsigned', COLUMN_TYPE) != 0 AND LOCATE('unsigned', DATA_TYPE) = 0 AND LOCATE('set', DATA_TYPE) <> 1 AND LOCATE('enum', DATA_TYPE) <> 1 THEN CONCAT(DATA_TYPE, ' unsigned') ELSE DATA_TYPE END) AS TYPE_NAME,");
		} else {
			sqlBuf.append("CASE WHEN LOCATE('unsigned', COLUMN_TYPE) != 0 AND LOCATE('unsigned', DATA_TYPE) = 0 AND LOCATE('set', DATA_TYPE) <> 1 AND LOCATE('enum', DATA_TYPE) <> 1 THEN CONCAT(DATA_TYPE, ' unsigned') ELSE DATA_TYPE END AS TYPE_NAME,");
		}

		sqlBuf
				.append("CASE WHEN LCASE(DATA_TYPE)='date' THEN 10 WHEN LCASE(DATA_TYPE)='time' THEN 8 WHEN LCASE(DATA_TYPE)='datetime' THEN 19 WHEN LCASE(DATA_TYPE)='timestamp' THEN 19 WHEN CHARACTER_MAXIMUM_LENGTH IS NULL THEN NUMERIC_PRECISION WHEN CHARACTER_MAXIMUM_LENGTH > " 
						+ Integer.MAX_VALUE + " THEN " + Integer.MAX_VALUE + " ELSE CHARACTER_MAXIMUM_LENGTH END AS COLUMN_SIZE, "
						+ MysqlIO.getMaxBuf() + " AS BUFFER_LENGTH,"
						+ "NUMERIC_SCALE AS DECIMAL_DIGITS,"
						+ "10 AS NUM_PREC_RADIX,"
						+ "CASE WHEN IS_NULLABLE='NO' THEN " + columnNoNulls + " ELSE CASE WHEN IS_NULLABLE='YES' THEN " + columnNullable + " ELSE " + columnNullableUnknown + " END END AS NULLABLE,"
						+ "COLUMN_COMMENT AS REMARKS,"
						+ "COLUMN_DEFAULT AS COLUMN_DEF,"
						+ "0 AS SQL_DATA_TYPE,"
						+ "0 AS SQL_DATETIME_SUB,"
						+ "CASE WHEN CHARACTER_OCTET_LENGTH > " + Integer.MAX_VALUE + " THEN " + Integer.MAX_VALUE + " ELSE CHARACTER_OCTET_LENGTH END AS CHAR_OCTET_LENGTH,"
						+ "ORDINAL_POSITION,"
						+ "IS_NULLABLE,"
						+ "NULL AS SCOPE_CATALOG,"
						+ "NULL AS SCOPE_SCHEMA,"
						+ "NULL AS SCOPE_TABLE,"
						+ "NULL AS SOURCE_DATA_TYPE,"
						+ "IF (EXTRA LIKE '%auto_increment%','YES','NO') AS IS_AUTOINCREMENT "
						+ "FROM INFORMATION_SCHEMA.COLUMNS WHERE ");

		final boolean operatingOnInformationSchema = "information_schema".equalsIgnoreCase(catalog);
		
		if (catalog != null) {
			if ((operatingOnInformationSchema) || ((StringUtils.indexOfIgnoreCase(0, catalog, "%") == -1) 
					&& (StringUtils.indexOfIgnoreCase(0, catalog, "_") == -1))) {
				sqlBuf.append("TABLE_SCHEMA = ? AND ");
			} else {
				sqlBuf.append("TABLE_SCHEMA LIKE ? AND ");
			}
			
		} else {
			sqlBuf.append("TABLE_SCHEMA LIKE ? AND ");
		}

		if (tableName != null) {
			if ((StringUtils.indexOfIgnoreCase(0, tableName, "%") == -1) 
					&& (StringUtils.indexOfIgnoreCase(0, tableName, "_") == -1)) {
				sqlBuf.append("TABLE_NAME = ? AND ");
			} else {
				sqlBuf.append("TABLE_NAME LIKE ? AND ");
			}
			
		} else {
			sqlBuf.append("TABLE_NAME LIKE ? AND ");
		}
		
		if ((StringUtils.indexOfIgnoreCase(0, columnNamePattern, "%") == -1) 
				&& (StringUtils.indexOfIgnoreCase(0, columnNamePattern, "_") == -1)) {
			sqlBuf.append("COLUMN_NAME = ? ");
		} else {
			sqlBuf.append("COLUMN_NAME LIKE ? ");
		}
		sqlBuf.append("ORDER BY TABLE_SCHEMA, TABLE_NAME, ORDINAL_POSITION");
		
		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sqlBuf.toString());
			
			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, tableName);
			pStmt.setString(3, columnNamePattern);

			ResultSet rs = executeMetadataQuery(pStmt);

			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createColumnsFields());
			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Get a description of the foreign key columns in the foreign key table
	 * that reference the primary key columns of the primary key table (describe
	 * how one table imports another's key.) This should normally return a
	 * single foreign key/primary key pair (most tables only import a foreign
	 * key from a table once.) They are ordered by FKTABLE_CAT, FKTABLE_SCHEM,
	 * FKTABLE_NAME, and KEY_SEQ.
	 * <P>
	 * Each foreign key column description has the following columns:
	 * <OL>
	 * <li> <B>PKTABLE_CAT</B> String => primary key table catalog (may be
	 * null) </li>
	 * <li> <B>PKTABLE_SCHEM</B> String => primary key table schema (may be
	 * null) </li>
	 * <li> <B>PKTABLE_NAME</B> String => primary key table name </li>
	 * <li> <B>PKCOLUMN_NAME</B> String => primary key column name </li>
	 * <li> <B>FKTABLE_CAT</B> String => foreign key table catalog (may be
	 * null) being exported (may be null) </li>
	 * <li> <B>FKTABLE_SCHEM</B> String => foreign key table schema (may be
	 * null) being exported (may be null) </li>
	 * <li> <B>FKTABLE_NAME</B> String => foreign key table name being exported
	 * </li>
	 * <li> <B>FKCOLUMN_NAME</B> String => foreign key column name being
	 * exported </li>
	 * <li> <B>KEY_SEQ</B> short => sequence number within foreign key </li>
	 * <li> <B>UPDATE_RULE</B> short => What happens to foreign key when
	 * primary is updated:
	 * <UL>
	 * <li> importedKeyCascade - change imported key to agree with primary key
	 * update </li>
	 * <li> importedKeyRestrict - do not allow update of primary key if it has
	 * been imported </li>
	 * <li> importedKeySetNull - change imported key to NULL if its primary key
	 * has been updated </li>
	 * </ul>
	 * </li>
	 * <li> <B>DELETE_RULE</B> short => What happens to the foreign key when
	 * primary is deleted.
	 * <UL>
	 * <li> importedKeyCascade - delete rows that import a deleted key </li>
	 * <li> importedKeyRestrict - do not allow delete of primary key if it has
	 * been imported </li>
	 * <li> importedKeySetNull - change imported key to NULL if its primary key
	 * has been deleted </li>
	 * </ul>
	 * </li>
	 * <li> <B>FK_NAME</B> String => foreign key identifier (may be null) </li>
	 * <li> <B>PK_NAME</B> String => primary key identifier (may be null) </li>
	 * </ol>
	 * </p>
	 * 
	 * @param primaryCatalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param primarySchema
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param primaryTable
	 *            a table name
	 * @param foreignCatalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param foreignSchema
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param foreignTable
	 *            a table name
	 * @return ResultSet each row is a foreign key column description
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public java.sql.ResultSet getCrossReference(String primaryCatalog,
			String primarySchema, String primaryTable, String foreignCatalog,
			String foreignSchema, String foreignTable) throws SQLException {
		if (primaryTable == null) {
			throw SQLError.createSQLException("Table not specified.",
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
		}

		if (primaryCatalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				primaryCatalog = this.database;	
			}
		}

		if (foreignCatalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				foreignCatalog = this.database;
			}
		}

		String sql = "SELECT "
				+ "A.REFERENCED_TABLE_SCHEMA AS PKTABLE_CAT,"
				+ "NULL AS PKTABLE_SCHEM,"
				+ "A.REFERENCED_TABLE_NAME AS PKTABLE_NAME,"
				+ "A.REFERENCED_COLUMN_NAME AS PKCOLUMN_NAME,"
				+ "A.TABLE_SCHEMA AS FKTABLE_CAT,"
				+ "NULL AS FKTABLE_SCHEM,"
				+ "A.TABLE_NAME AS FKTABLE_NAME, "
				+ "A.COLUMN_NAME AS FKCOLUMN_NAME, "
				+ "A.ORDINAL_POSITION AS KEY_SEQ,"
				+ generateUpdateRuleClause()
				+ " AS UPDATE_RULE,"
				+ generateDeleteRuleClause()
				+ " AS DELETE_RULE,"
				+ "A.CONSTRAINT_NAME AS FK_NAME,"
				+ "(SELECT CONSTRAINT_NAME FROM"
				+ " INFORMATION_SCHEMA.TABLE_CONSTRAINTS"
				+ " WHERE TABLE_SCHEMA = A.REFERENCED_TABLE_SCHEMA AND"
				+ " TABLE_NAME = A.REFERENCED_TABLE_NAME AND"
				+ " CONSTRAINT_TYPE IN ('UNIQUE','PRIMARY KEY') LIMIT 1)"
				+ " AS PK_NAME,"
				+ importedKeyNotDeferrable
				+ " AS DEFERRABILITY "
				+ "FROM "
				+ "INFORMATION_SCHEMA.KEY_COLUMN_USAGE A JOIN "
				+ "INFORMATION_SCHEMA.TABLE_CONSTRAINTS B "
				+ "USING (TABLE_SCHEMA, TABLE_NAME, CONSTRAINT_NAME) "
				+ generateOptionalRefContraintsJoin()
				+ "WHERE "
				+ "B.CONSTRAINT_TYPE = 'FOREIGN KEY' "
				+ "AND A.REFERENCED_TABLE_SCHEMA LIKE ? AND A.REFERENCED_TABLE_NAME=? "
				+ "AND A.TABLE_SCHEMA LIKE ? AND A.TABLE_NAME=? " + "ORDER BY "
				+ "A.TABLE_SCHEMA, A.TABLE_NAME, A.ORDINAL_POSITION";

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			if (primaryCatalog != null) {
				pStmt.setString(1, primaryCatalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, primaryTable);
			
			if (foreignCatalog != null) {
				pStmt.setString(3, foreignCatalog);
			} else {
				pStmt.setString(3, "%");
			}
			
			pStmt.setString(4, foreignTable);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createFkMetadataFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Get a description of a foreign key columns that reference a table's
	 * primary key columns (the foreign keys exported by a table). They are
	 * ordered by FKTABLE_CAT, FKTABLE_SCHEM, FKTABLE_NAME, and KEY_SEQ.
	 * <P>
	 * Each foreign key column description has the following columns:
	 * <OL>
	 * <li> <B>PKTABLE_CAT</B> String => primary key table catalog (may be
	 * null) </li>
	 * <li> <B>PKTABLE_SCHEM</B> String => primary key table schema (may be
	 * null) </li>
	 * <li> <B>PKTABLE_NAME</B> String => primary key table name </li>
	 * <li> <B>PKCOLUMN_NAME</B> String => primary key column name </li>
	 * <li> <B>FKTABLE_CAT</B> String => foreign key table catalog (may be
	 * null) being exported (may be null) </li>
	 * <li> <B>FKTABLE_SCHEM</B> String => foreign key table schema (may be
	 * null) being exported (may be null) </li>
	 * <li> <B>FKTABLE_NAME</B> String => foreign key table name being exported
	 * </li>
	 * <li> <B>FKCOLUMN_NAME</B> String => foreign key column name being
	 * exported </li>
	 * <li> <B>KEY_SEQ</B> short => sequence number within foreign key </li>
	 * <li> <B>UPDATE_RULE</B> short => What happens to foreign key when
	 * primary is updated:
	 * <UL>
	 * <li> importedKeyCascade - change imported key to agree with primary key
	 * update </li>
	 * <li> importedKeyRestrict - do not allow update of primary key if it has
	 * been imported </li>
	 * <li> importedKeySetNull - change imported key to NULL if its primary key
	 * has been updated </li>
	 * </ul>
	 * </li>
	 * <li> <B>DELETE_RULE</B> short => What happens to the foreign key when
	 * primary is deleted.
	 * <UL>
	 * <li> importedKeyCascade - delete rows that import a deleted key </li>
	 * <li> importedKeyRestrict - do not allow delete of primary key if it has
	 * been imported </li>
	 * <li> importedKeySetNull - change imported key to NULL if its primary key
	 * has been deleted </li>
	 * </ul>
	 * </li>
	 * <li> <B>FK_NAME</B> String => foreign key identifier (may be null) </li>
	 * <li> <B>PK_NAME</B> String => primary key identifier (may be null) </li>
	 * </ol>
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schema
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param table
	 *            a table name
	 * @return ResultSet each row is a foreign key column description
	 * @throws SQLException
	 *             if a database access error occurs
	 * @see #getImportedKeys
	 */
	public java.sql.ResultSet getExportedKeys(String catalog, String schema,
			String table) throws SQLException {
		// TODO: Can't determine actions using INFORMATION_SCHEMA yet...

		if (table == null) {
			throw SQLError.createSQLException("Table not specified.",
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
		}

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}	
		}
		
		//CASCADE, SET NULL, SET DEFAULT, RESTRICT, NO ACTION

		String sql = "SELECT "
				+ "A.REFERENCED_TABLE_SCHEMA AS PKTABLE_CAT,"
				+ "NULL AS PKTABLE_SCHEM,"
				+ "A.REFERENCED_TABLE_NAME AS PKTABLE_NAME, "
				+ "A.REFERENCED_COLUMN_NAME AS PKCOLUMN_NAME, "
				+ "A.TABLE_SCHEMA AS FKTABLE_CAT,"
				+ "NULL AS FKTABLE_SCHEM,"
				+ "A.TABLE_NAME AS FKTABLE_NAME,"
				+ "A.COLUMN_NAME AS FKCOLUMN_NAME, "
				+ "A.ORDINAL_POSITION AS KEY_SEQ,"
				+ generateUpdateRuleClause()
				+ " AS UPDATE_RULE,"
				+ generateDeleteRuleClause()
				+ " AS DELETE_RULE,"
				+ "A.CONSTRAINT_NAME AS FK_NAME,"
				+ "(SELECT CONSTRAINT_NAME FROM"
				+ " INFORMATION_SCHEMA.TABLE_CONSTRAINTS"
				+ " WHERE TABLE_SCHEMA = A.REFERENCED_TABLE_SCHEMA AND"
				+ " TABLE_NAME = A.REFERENCED_TABLE_NAME AND"
				+ " CONSTRAINT_TYPE IN ('UNIQUE','PRIMARY KEY') LIMIT 1)"
				+ " AS PK_NAME,"
				+ importedKeyNotDeferrable
				+ " AS DEFERRABILITY "
				+ "FROM "
				+ "INFORMATION_SCHEMA.KEY_COLUMN_USAGE A JOIN "
				+ "INFORMATION_SCHEMA.TABLE_CONSTRAINTS B "
				+ "USING (TABLE_SCHEMA, TABLE_NAME, CONSTRAINT_NAME) "
				+ generateOptionalRefContraintsJoin()
				+ "WHERE "
				+ "B.CONSTRAINT_TYPE = 'FOREIGN KEY' "
				+ "AND A.REFERENCED_TABLE_SCHEMA LIKE ? AND A.REFERENCED_TABLE_NAME=? "
				+ "ORDER BY A.TABLE_SCHEMA, A.TABLE_NAME, A.ORDINAL_POSITION";

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			
			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, table);

			ResultSet rs = executeMetadataQuery(pStmt);

			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createFkMetadataFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}

	}

	private String generateOptionalRefContraintsJoin() {
		return ((this.hasReferentialConstraintsView) ? "JOIN " 
				+ "INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS R "
				+ "ON (R.CONSTRAINT_NAME = B.CONSTRAINT_NAME "
				+ "AND R.TABLE_NAME = B.TABLE_NAME AND "
				+ "R.CONSTRAINT_SCHEMA = B.TABLE_SCHEMA) " : "");
	}

	private String generateDeleteRuleClause() {
		return ((this.hasReferentialConstraintsView) ? 
				"CASE WHEN R.DELETE_RULE='CASCADE' THEN " + String.valueOf(importedKeyCascade) 
				+ " WHEN R.DELETE_RULE='SET NULL' THEN " + String.valueOf(importedKeySetNull)  
				+ " WHEN R.DELETE_RULE='SET DEFAULT' THEN " + String.valueOf(importedKeySetDefault) 
				+ " WHEN R.DELETE_RULE='RESTRICT' THEN " + String.valueOf(importedKeyRestrict)
				+ " WHEN R.DELETE_RULE='NO ACTION' THEN " + String.valueOf(importedKeyNoAction)
				+ " ELSE " + String.valueOf(importedKeyNoAction) + " END " : String.valueOf(importedKeyRestrict));
	}

	private String generateUpdateRuleClause() {
		return ((this.hasReferentialConstraintsView) ? 
				"CASE WHEN R.UPDATE_RULE='CASCADE' THEN " + String.valueOf(importedKeyCascade) 
				+ " WHEN R.UPDATE_RULE='SET NULL' THEN " + String.valueOf(importedKeySetNull)  
				+ " WHEN R.UPDATE_RULE='SET DEFAULT' THEN " + String.valueOf(importedKeySetDefault) 
				+ " WHEN R.UPDATE_RULE='RESTRICT' THEN " + String.valueOf(importedKeyRestrict)
				+ " WHEN R.UPDATE_RULE='NO ACTION' THEN " + String.valueOf(importedKeyNoAction)
				+ " ELSE " + String.valueOf(importedKeyNoAction) + " END " : String.valueOf(importedKeyRestrict));
	}

	/**
	 * Get a description of the primary key columns that are referenced by a
	 * table's foreign key columns (the primary keys imported by a table). They
	 * are ordered by PKTABLE_CAT, PKTABLE_SCHEM, PKTABLE_NAME, and KEY_SEQ.
	 * <P>
	 * Each primary key column description has the following columns:
	 * <OL>
	 * <li> <B>PKTABLE_CAT</B> String => primary key table catalog being
	 * imported (may be null) </li>
	 * <li> <B>PKTABLE_SCHEM</B> String => primary key table schema being
	 * imported (may be null) </li>
	 * <li> <B>PKTABLE_NAME</B> String => primary key table name being imported
	 * </li>
	 * <li> <B>PKCOLUMN_NAME</B> String => primary key column name being
	 * imported </li>
	 * <li> <B>FKTABLE_CAT</B> String => foreign key table catalog (may be
	 * null) </li>
	 * <li> <B>FKTABLE_SCHEM</B> String => foreign key table schema (may be
	 * null) </li>
	 * <li> <B>FKTABLE_NAME</B> String => foreign key table name </li>
	 * <li> <B>FKCOLUMN_NAME</B> String => foreign key column name </li>
	 * <li> <B>KEY_SEQ</B> short => sequence number within foreign key </li>
	 * <li> <B>UPDATE_RULE</B> short => What happens to foreign key when
	 * primary is updated:
	 * <UL>
	 * <li> importedKeyCascade - change imported key to agree with primary key
	 * update </li>
	 * <li> importedKeyRestrict - do not allow update of primary key if it has
	 * been imported </li>
	 * <li> importedKeySetNull - change imported key to NULL if its primary key
	 * has been updated </li>
	 * </ul>
	 * </li>
	 * <li> <B>DELETE_RULE</B> short => What happens to the foreign key when
	 * primary is deleted.
	 * <UL>
	 * <li> importedKeyCascade - delete rows that import a deleted key </li>
	 * <li> importedKeyRestrict - do not allow delete of primary key if it has
	 * been imported </li>
	 * <li> importedKeySetNull - change imported key to NULL if its primary key
	 * has been deleted </li>
	 * </ul>
	 * </li>
	 * <li> <B>FK_NAME</B> String => foreign key name (may be null) </li>
	 * <li> <B>PK_NAME</B> String => primary key name (may be null) </li>
	 * </ol>
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schema
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param table
	 *            a table name
	 * @return ResultSet each row is a primary key column description
	 * @throws SQLException
	 *             if a database access error occurs
	 * @see #getExportedKeys
	 */
	public java.sql.ResultSet getImportedKeys(String catalog, String schema,
			String table) throws SQLException {
		if (table == null) {
			throw SQLError.createSQLException("Table not specified.",
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
		}

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}
		}

		String sql = "SELECT "
				+ "A.REFERENCED_TABLE_SCHEMA AS PKTABLE_CAT,"
				+ "NULL AS PKTABLE_SCHEM,"
				+ "A.REFERENCED_TABLE_NAME AS PKTABLE_NAME,"
				+ "A.REFERENCED_COLUMN_NAME AS PKCOLUMN_NAME,"
				+ "A.TABLE_SCHEMA AS FKTABLE_CAT,"
				+ "NULL AS FKTABLE_SCHEM,"
				+ "A.TABLE_NAME AS FKTABLE_NAME, "
				+ "A.COLUMN_NAME AS FKCOLUMN_NAME, "
				+ "A.ORDINAL_POSITION AS KEY_SEQ,"
				+ generateUpdateRuleClause()
				+ " AS UPDATE_RULE,"
				+ generateDeleteRuleClause()
				+ " AS DELETE_RULE,"
				+ "A.CONSTRAINT_NAME AS FK_NAME,"
				+ "(SELECT CONSTRAINT_NAME FROM"
				+ " INFORMATION_SCHEMA.TABLE_CONSTRAINTS"
				+ " WHERE TABLE_SCHEMA = A.REFERENCED_TABLE_SCHEMA AND"
				+ " TABLE_NAME = A.REFERENCED_TABLE_NAME AND"
				+ " CONSTRAINT_TYPE IN ('UNIQUE','PRIMARY KEY') LIMIT 1)"
				+ " AS PK_NAME,"
				+ importedKeyNotDeferrable
				+ " AS DEFERRABILITY "
				+ "FROM "
				+ "INFORMATION_SCHEMA.KEY_COLUMN_USAGE A "
				+ "JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS B USING "
				+ "(CONSTRAINT_NAME, TABLE_NAME) "
				+ generateOptionalRefContraintsJoin()
				+ "WHERE "
				+ "B.CONSTRAINT_TYPE = 'FOREIGN KEY' "
				+ "AND A.TABLE_SCHEMA LIKE ? "
				+ "AND A.TABLE_NAME=? "
				+ "AND A.REFERENCED_TABLE_SCHEMA IS NOT NULL "
				+ "ORDER BY "
				+ "A.REFERENCED_TABLE_SCHEMA, A.REFERENCED_TABLE_NAME, "
				+ "A.ORDINAL_POSITION";

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			
			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, table);

			ResultSet rs = executeMetadataQuery(pStmt);

			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createFkMetadataFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Get a description of a table's indices and statistics. They are ordered
	 * by NON_UNIQUE, TYPE, INDEX_NAME, and ORDINAL_POSITION.
	 * <P>
	 * Each index column description has the following columns:
	 * <OL>
	 * <li> <B>TABLE_CAT</B> String => table catalog (may be null) </li>
	 * <li> <B>TABLE_SCHEM</B> String => table schema (may be null) </li>
	 * <li> <B>TABLE_NAME</B> String => table name </li>
	 * <li> <B>NON_UNIQUE</B> boolean => Can index values be non-unique? false
	 * when TYPE is tableIndexStatistic </li>
	 * <li> <B>INDEX_QUALIFIER</B> String => index catalog (may be null); null
	 * when TYPE is tableIndexStatistic </li>
	 * <li> <B>INDEX_NAME</B> String => index name; null when TYPE is
	 * tableIndexStatistic </li>
	 * <li> <B>TYPE</B> short => index type:
	 * <UL>
	 * <li> tableIndexStatistic - this identifies table statistics that are
	 * returned in conjuction with a table's index descriptions </li>
	 * <li> tableIndexClustered - this is a clustered index </li>
	 * <li> tableIndexHashed - this is a hashed index </li>
	 * <li> tableIndexOther - this is some other style of index </li>
	 * </ul>
	 * </li>
	 * <li> <B>ORDINAL_POSITION</B> short => column sequence number within
	 * index; zero when TYPE is tableIndexStatistic </li>
	 * <li> <B>COLUMN_NAME</B> String => column name; null when TYPE is
	 * tableIndexStatistic </li>
	 * <li> <B>ASC_OR_DESC</B> String => column sort sequence, "A" =>
	 * ascending, "D" => descending, may be null if sort sequence is not
	 * supported; null when TYPE is tableIndexStatistic </li>
	 * <li> <B>CARDINALITY</B> int => When TYPE is tableIndexStatisic then this
	 * is the number of rows in the table; otherwise it is the number of unique
	 * values in the index. </li>
	 * <li> <B>PAGES</B> int => When TYPE is tableIndexStatisic then this is
	 * the number of pages used for the table, otherwise it is the number of
	 * pages used for the current index. </li>
	 * <li> <B>FILTER_CONDITION</B> String => Filter condition, if any. (may be
	 * null) </li>
	 * </ol>
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schema
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param table
	 *            a table name
	 * @param unique
	 *            when true, return only indices for unique values; when false,
	 *            return indices regardless of whether unique or not
	 * @param approximate
	 *            when true, result is allowed to reflect approximate or out of
	 *            data values; when false, results are requested to be accurate
	 * @return ResultSet each row is an index column description
	 * @throws SQLException
	 *             DOCUMENT ME!
	 */
	public ResultSet getIndexInfo(String catalog, String schema, String table,
			boolean unique, boolean approximate) throws SQLException {
		StringBuffer sqlBuf = new StringBuffer("SELECT "
				+ "TABLE_SCHEMA AS TABLE_CAT, " + "NULL AS TABLE_SCHEM,"
				+ "TABLE_NAME," + "NON_UNIQUE,"
				+ "TABLE_SCHEMA AS INDEX_QUALIFIER," + "INDEX_NAME,"
				+ tableIndexOther + " AS TYPE,"
				+ "SEQ_IN_INDEX AS ORDINAL_POSITION," + "COLUMN_NAME,"
				+ "COLLATION AS ASC_OR_DESC," + "CARDINALITY,"
				+ "NULL AS PAGES," + "NULL AS FILTER_CONDITION "
				+ "FROM INFORMATION_SCHEMA.STATISTICS WHERE "
				+ "TABLE_SCHEMA LIKE ? AND " + "TABLE_NAME LIKE ?");

		if (unique) {
			sqlBuf.append(" AND NON_UNIQUE=0 ");
		}

		sqlBuf.append("ORDER BY NON_UNIQUE, INDEX_NAME, SEQ_IN_INDEX");

		java.sql.PreparedStatement pStmt = null;

		try {
			if (catalog == null) {
				if (this.conn.getNullCatalogMeansCurrent()) {
					catalog = this.database;
				}
			}
			
			pStmt = prepareMetaDataSafeStatement(sqlBuf.toString());

			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, table);

			ResultSet rs = executeMetadataQuery(pStmt);

			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createIndexInfoFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Get a description of a table's primary key columns. They are ordered by
	 * COLUMN_NAME.
	 * <P>
	 * Each column description has the following columns:
	 * <OL>
	 * <li> <B>TABLE_CAT</B> String => table catalog (may be null) </li>
	 * <li> <B>TABLE_SCHEM</B> String => table schema (may be null) </li>
	 * <li> <B>TABLE_NAME</B> String => table name </li>
	 * <li> <B>COLUMN_NAME</B> String => column name </li>
	 * <li> <B>KEY_SEQ</B> short => sequence number within primary key </li>
	 * <li> <B>PK_NAME</B> String => primary key name (may be null) </li>
	 * </ol>
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schema
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param table
	 *            a table name
	 * @return ResultSet each row is a primary key column description
	 * @throws SQLException
	 *             DOCUMENT ME!
	 */
	public java.sql.ResultSet getPrimaryKeys(String catalog, String schema,
			String table) throws SQLException {

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}
		}

		if (table == null) {
			throw SQLError.createSQLException("Table not specified.",
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
		}

		String sql = "SELECT TABLE_SCHEMA AS TABLE_CAT, NULL AS TABLE_SCHEM, TABLE_NAME, "
				+ "COLUMN_NAME, SEQ_IN_INDEX AS KEY_SEQ, 'PRIMARY' AS PK_NAME FROM INFORMATION_SCHEMA.STATISTICS "
				+ "WHERE TABLE_SCHEMA LIKE ? AND TABLE_NAME LIKE ? AND "
				+ "INDEX_NAME='PRIMARY' ORDER BY TABLE_SCHEMA, TABLE_NAME, INDEX_NAME, SEQ_IN_INDEX";

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sql);

			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, table);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(new Field[] {
					new Field("", "TABLE_CAT", Types.CHAR, 255),
					new Field("", "TABLE_SCHEM", Types.CHAR, 0),
					new Field("", "TABLE_NAME", Types.CHAR, 255),
					new Field("", "COLUMN_NAME", Types.CHAR, 32),
					new Field("", "KEY_SEQ", Types.SMALLINT, 5),
					new Field("", "PK_NAME", Types.CHAR, 32) });

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Get a description of stored procedures available in a catalog.
	 * <P>
	 * Only procedure descriptions matching the schema and procedure name
	 * criteria are returned. They are ordered by PROCEDURE_SCHEM, and
	 * PROCEDURE_NAME.
	 * </p>
	 * <P>
	 * Each procedure description has the the following columns:
	 * <OL>
	 * <li> <B>PROCEDURE_CAT</B> String => procedure catalog (may be null)
	 * </li>
	 * <li> <B>PROCEDURE_SCHEM</B> String => procedure schema (may be null)
	 * </li>
	 * <li> <B>PROCEDURE_NAME</B> String => procedure name </li>
	 * <li> reserved for future use </li>
	 * <li> reserved for future use </li>
	 * <li> reserved for future use </li>
	 * <li> <B>REMARKS</B> String => explanatory comment on the procedure </li>
	 * <li> <B>PROCEDURE_TYPE</B> short => kind of procedure:
	 * <UL>
	 * <li> procedureResultUnknown - May return a result </li>
	 * <li> procedureNoResult - Does not return a result </li>
	 * <li> procedureReturnsResult - Returns a result </li>
	 * </ul>
	 * </li>
	 * </ol>
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schemaPattern
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param procedureNamePattern
	 *            a procedure name pattern
	 * @return ResultSet each row is a procedure description
	 * @throws SQLException
	 *             if a database access error occurs
	 * @see #getSearchStringEscape
	 */
	public ResultSet getProcedures(String catalog, String schemaPattern,
			String procedureNamePattern) throws SQLException {

		if ((procedureNamePattern == null)
				|| (procedureNamePattern.length() == 0)) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				procedureNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Procedure name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		String db = null;

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				db = this.database;
			}
		}  else {
			db = catalog;
		}

		String sql = "SELECT ROUTINE_SCHEMA AS PROCEDURE_CAT, "
				+ "NULL AS PROCEDURE_SCHEM, "
				+ "ROUTINE_NAME AS PROCEDURE_NAME, " + "NULL AS RESERVED_1, "
				+ "NULL AS RESERVED_2, " + "NULL AS RESERVED_3, "
				+ "ROUTINE_COMMENT AS REMARKS, "
				+ "CASE WHEN ROUTINE_TYPE = 'PROCEDURE' THEN "
				+ procedureNoResult + " WHEN ROUTINE_TYPE='FUNCTION' THEN "
				+ procedureReturnsResult + " ELSE " + procedureResultUnknown
				+ " END AS PROCEDURE_TYPE, "
				+ "ROUTINE_NAME AS SPECIFIC_NAME "
				+ "FROM INFORMATION_SCHEMA.ROUTINES WHERE "
				+ getRoutineTypeConditionForGetProcedures()
				+ "ROUTINE_SCHEMA LIKE ? AND ROUTINE_NAME LIKE ? "
				+ "ORDER BY ROUTINE_SCHEMA, ROUTINE_NAME";

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			
			if (db != null) {
				pStmt.setString(1, db);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, procedureNamePattern);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createFieldMetadataForGetProcedures());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Returns a condition to be injected in the query that returns metadata for procedures only. Overridden by
	 * subclasses when needed. When not empty must end with "AND ".
	 * 
	 * @return String with the condition to be injected.
	 */
	protected String getRoutineTypeConditionForGetProcedures() {
		return "";
	}
	
    /**
     * Retrieves a description of the given catalog's stored procedure parameter
     * and result columns.
     *
     * <P>Only descriptions matching the schema, procedure and
     * parameter name criteria are returned.  They are ordered by
     * PROCEDURE_SCHEM and PROCEDURE_NAME. Within this, the return value,
     * if any, is first. Next are the parameter descriptions in call
     * order. The column descriptions follow in column number order.
     *
     * <P>Each row in the <code>ResultSet</code> is a parameter description or
     * column description with the following fields:
     *  <OL>
     *	<LI><B>PROCEDURE_CAT</B> String => procedure catalog (may be <code>null</code>)
     *	<LI><B>PROCEDURE_SCHEM</B> String => procedure schema (may be <code>null</code>)
     *	<LI><B>PROCEDURE_NAME</B> String => procedure name
     *	<LI><B>COLUMN_NAME</B> String => column/parameter name 
     *	<LI><B>COLUMN_TYPE</B> Short => kind of column/parameter:
     *      <UL>
     *      <LI> procedureColumnUnknown - nobody knows
     *      <LI> procedureColumnIn - IN parameter
     *      <LI> procedureColumnInOut - INOUT parameter
     *      <LI> procedureColumnOut - OUT parameter
     *      <LI> procedureColumnReturn - procedure return value
     *      <LI> procedureColumnResult - result column in <code>ResultSet</code>
     *      </UL>
     *  <LI><B>DATA_TYPE</B> int => SQL type from java.sql.Types
     *	<LI><B>TYPE_NAME</B> String => SQL type name, for a UDT type the
     *  type name is fully qualified
     *	<LI><B>PRECISION</B> int => precision
     *	<LI><B>LENGTH</B> int => length in bytes of data
     *	<LI><B>SCALE</B> short => scale
     *	<LI><B>RADIX</B> short => radix
     *	<LI><B>NULLABLE</B> short => can it contain NULL.
     *      <UL>
     *      <LI> procedureNoNulls - does not allow NULL values
     *      <LI> procedureNullable - allows NULL values
     *      <LI> procedureNullableUnknown - nullability unknown
     *      </UL>
     *	<LI><B>REMARKS</B> String => comment describing parameter/column
     *  </OL>
     *
     * <P><B>Note:</B> Some databases may not return the column
     * descriptions for a procedure. Additional columns beyond
     * REMARKS can be defined by the database.
     *
     * @param catalog a catalog name; must match the catalog name as it
     *        is stored in the database; "" retrieves those without a catalog;
     *        <code>null</code> means that the catalog name should not be used to narrow
     *        the search
     * @param schemaPattern a schema name pattern; must match the schema name
     *        as it is stored in the database; "" retrieves those without a schema;
     *        <code>null</code> means that the schema name should not be used to narrow
     *        the search
     * @param procedureNamePattern a procedure name pattern; must match the
     *        procedure name as it is stored in the database 
     * @param columnNamePattern a column name pattern; must match the column name
     *        as it is stored in the database 
     * @return <code>ResultSet</code> - each row describes a stored procedure parameter or 
     *      column
     * @exception SQLException if a database access error occurs
     * @see #getSearchStringEscape 
     */
	public ResultSet getProcedureColumns(String catalog, String schemaPattern,
			String procedureNamePattern, String columnNamePattern)
			throws SQLException {
		if (!this.hasParametersView) {
			return getProcedureColumnsNoISParametersView(catalog, schemaPattern, procedureNamePattern, columnNamePattern);
		}
		
		if ((procedureNamePattern == null)
				|| (procedureNamePattern.length() == 0)) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				procedureNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Procedure name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		String db = null;

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				db = this.database;
			}
		}  else {
			db = catalog;
		}		

		// Here's what we get from MySQL ...
		// SPECIFIC_CATALOG                             NULL 
		// SPECIFIC_SCHEMA                              db17 
		// SPECIFIC_NAME                                p 
		// ORDINAL_POSITION                             1 
		// PARAMETER_MODE                               OUT 
		// PARAMETER_NAME                               a 
		// DATA_TYPE                                    int 
		// CHARACTER_MAXIMUM_LENGTH                     NULL 
		// CHARACTER_OCTET_LENGTH                       NULL 
		// CHARACTER_SET_NAME                           NULL 
		// COLLATION_NAME                               NULL 
		// NUMERIC_PRECISION                            10 
		// NUMERIC_SCALE                                0 
		// DTD_IDENTIFIER                               int(11)

		StringBuffer sqlBuf = new StringBuffer("SELECT SPECIFIC_SCHEMA AS PROCEDURE_CAT, "
				+ "NULL AS `PROCEDURE_SCHEM`, "
				+ "SPECIFIC_NAME AS `PROCEDURE_NAME`, "
				+ "IFNULL(PARAMETER_NAME, '') AS `COLUMN_NAME`, "
				+ "CASE WHEN PARAMETER_MODE = 'IN' THEN " + procedureColumnIn
					+ " WHEN PARAMETER_MODE = 'OUT' THEN " + procedureColumnOut 
					+ " WHEN PARAMETER_MODE = 'INOUT' THEN " + procedureColumnInOut
					+ " WHEN ORDINAL_POSITION = 0 THEN " + procedureColumnReturn 
					+ " ELSE " + procedureColumnUnknown
				+ " END AS `COLUMN_TYPE`, ");
		
		//DATA_TYPE
		MysqlDefs.appendJdbcTypeMappingQuery(sqlBuf, "DATA_TYPE");

		sqlBuf.append(" AS `DATA_TYPE`, ");

		// TYPE_NAME
		if (conn.getCapitalizeTypeNames()) {
			sqlBuf.append("UPPER(CASE WHEN LOCATE('unsigned', DATA_TYPE) != 0 AND LOCATE('unsigned', DATA_TYPE) = 0 THEN CONCAT(DATA_TYPE, ' unsigned') ELSE DATA_TYPE END) AS `TYPE_NAME`,");
		} else {
			sqlBuf.append("CASE WHEN LOCATE('unsigned', DATA_TYPE) != 0 AND LOCATE('unsigned', DATA_TYPE) = 0 THEN CONCAT(DATA_TYPE, ' unsigned') ELSE DATA_TYPE END AS `TYPE_NAME`,");
		}

		// PRECISION</B> int => precision
		sqlBuf.append("NUMERIC_PRECISION AS `PRECISION`, ");
		// LENGTH</B> int => length in bytes of data
		sqlBuf
				.append("CASE WHEN LCASE(DATA_TYPE)='date' THEN 10 WHEN LCASE(DATA_TYPE)='time' THEN 8 WHEN LCASE(DATA_TYPE)='datetime' THEN 19 WHEN LCASE(DATA_TYPE)='timestamp' THEN 19 WHEN CHARACTER_MAXIMUM_LENGTH IS NULL THEN NUMERIC_PRECISION WHEN CHARACTER_MAXIMUM_LENGTH > " 
						+ Integer.MAX_VALUE + " THEN " + Integer.MAX_VALUE + " ELSE CHARACTER_MAXIMUM_LENGTH END AS LENGTH, ");
		
		// SCALE</B> short => scale
		sqlBuf.append("NUMERIC_SCALE AS `SCALE`, ");
		// RADIX</B> short => radix
		sqlBuf.append("10 AS RADIX,");
		sqlBuf.append(procedureNullable + " AS `NULLABLE`, "
				+ "NULL AS `REMARKS`, "
				+ "NULL AS `COLUMN_DEF`, "
				+ "NULL AS `SQL_DATA_TYPE`, "
				+ "NULL AS `SQL_DATETIME_SUB`, "
				+ "CHARACTER_OCTET_LENGTH AS `CHAR_OCTET_LENGTH`, "
				+ "ORDINAL_POSITION, "
				+ "'YES' AS `IS_NULLABLE`, "
				+ "SPECIFIC_NAME "
				+ "FROM INFORMATION_SCHEMA.PARAMETERS WHERE "
				+ getRoutineTypeConditionForGetProcedureColumns()
				+ "SPECIFIC_SCHEMA LIKE ? AND SPECIFIC_NAME LIKE ? AND (PARAMETER_NAME LIKE ? OR PARAMETER_NAME IS NULL) "
				+ "ORDER BY SPECIFIC_SCHEMA, SPECIFIC_NAME, ORDINAL_POSITION");

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sqlBuf.toString());
			
			if (db != null) {
				pStmt.setString(1, db);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, procedureNamePattern);
			pStmt.setString(3, columnNamePattern);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createProcedureColumnsFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Redirects to another implementation of #getProcedureColumns. Subclasses may need to override this method.
	 * 
	 * @see getProcedureColumns
	 */
	protected ResultSet getProcedureColumnsNoISParametersView(String catalog, String schemaPattern,
			String procedureNamePattern, String columnNamePattern) throws SQLException {
		return super.getProcedureColumns(catalog, schemaPattern, procedureNamePattern, columnNamePattern);
	}
	
	/**
	 * Returns a condition to be injected in the query that returns metadata for procedure columns only. Overridden by
	 * subclasses when needed. When not empty must end with "AND ".
	 * 
	 * @return String with the condition to be injected.
	 */
	protected String getRoutineTypeConditionForGetProcedureColumns() {
		return "";
	}

	/**
	 * Get a description of tables available in a catalog.
	 * <P>
	 * Only table descriptions matching the catalog, schema, table name and type
	 * criteria are returned. They are ordered by TABLE_TYPE, TABLE_SCHEM and
	 * TABLE_NAME.
	 * </p>
	 * <P>
	 * Each table description has the following columns:
	 * <OL>
	 * <li> <B>TABLE_CAT</B> String => table catalog (may be null) </li>
	 * <li> <B>TABLE_SCHEM</B> String => table schema (may be null) </li>
	 * <li> <B>TABLE_NAME</B> String => table name </li>
	 * <li> <B>TABLE_TYPE</B> String => table type. Typical types are "TABLE",
	 * "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL TEMPORARY", "ALIAS",
	 * "SYNONYM". </li>
	 * <li> <B>REMARKS</B> String => explanatory comment on the table </li>
	 * </ol>
	 * </p>
	 * <P>
	 * <B>Note:</B> Some databases may not return information for all tables.
	 * </p>
	 * 
	 * @param catalog
	 *            a catalog name; "" retrieves those without a catalog
	 * @param schemaPattern
	 *            a schema name pattern; "" retrieves those without a schema
	 * @param tableNamePattern
	 *            a table name pattern
	 * @param types
	 *            a list of table types to include; null returns all types
	 * @return ResultSet each row is a table description
	 * @throws SQLException
	 *             DOCUMENT ME!
	 * @see #getSearchStringEscape
	 */
	public ResultSet getTables(String catalog, String schemaPattern,
			String tableNamePattern, String[] types) throws SQLException {
		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}
		}

		if (tableNamePattern == null) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				tableNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Table name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		final String tableNamePat;
		String tmpCat = "";
		
		if ((catalog == null) || (catalog.length() == 0)) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				tmpCat = this.database;
			}
		} else {
			tmpCat = catalog;
		}
		
		List<String> parseList = StringUtils.splitDBdotName(tableNamePattern, tmpCat, 
				quotedId , conn.isNoBackslashEscapesSet());
		//There *should* be 2 rows, if any.
		if (parseList.size() == 2) {
			tableNamePat = parseList.get(1);
		} else {
			tableNamePat = tableNamePattern;
		}

		java.sql.PreparedStatement pStmt = null;

		String sql = "SELECT TABLE_SCHEMA AS TABLE_CAT, "
				+ "NULL AS TABLE_SCHEM, TABLE_NAME, "
				+ "CASE WHEN TABLE_TYPE='BASE TABLE' THEN 'TABLE' WHEN TABLE_TYPE='TEMPORARY' THEN 'LOCAL_TEMPORARY' ELSE TABLE_TYPE END AS TABLE_TYPE, "
				+ "TABLE_COMMENT AS REMARKS, NULL AS TYPE_CAT, NULL AS TYPE_SCHEM, NULL AS TYPE_NAME, NULL AS SELF_REFERENCING_COL_NAME, NULL AS REF_GENERATION "
				+ "FROM INFORMATION_SCHEMA.TABLES WHERE ";
		
		final boolean operatingOnInformationSchema = "information_schema".equalsIgnoreCase(catalog);
		if (catalog != null) {
			if ((operatingOnInformationSchema) || ((StringUtils.indexOfIgnoreCase(0, catalog, "%") == -1) 
					&& (StringUtils.indexOfIgnoreCase(0, catalog, "_") == -1))) {
				sql = sql + "TABLE_SCHEMA = ? AND ";
			} else {
				sql = sql + "TABLE_SCHEMA LIKE ? AND ";
			}
			
		} else {
			sql = sql + "TABLE_SCHEMA LIKE ? AND ";
		}

		if (tableNamePat != null) {
			if ((StringUtils.indexOfIgnoreCase(0, tableNamePat, "%") == -1) 
					&& (StringUtils.indexOfIgnoreCase(0, tableNamePat, "_") == -1)) {
				sql = sql + "TABLE_NAME = ? AND ";
			} else {
				sql = sql + "TABLE_NAME LIKE ? AND ";
			}
			
		} else {
			sql = sql + "TABLE_NAME LIKE ? AND ";
		}
		sql = sql + "TABLE_TYPE IN (?,?,?) ";
		sql = sql + "ORDER BY TABLE_TYPE, TABLE_SCHEMA, TABLE_NAME";
		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			
			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, tableNamePat);

			// This overloading of IN (...) allows us to cache this
			// prepared statement
			if (types == null || types.length == 0) {
				pStmt.setString(3, "BASE TABLE");
				pStmt.setString(4, "VIEW");
				pStmt.setString(5, "TEMPORARY");
			} else {
				pStmt.setNull(3, Types.VARCHAR);
				pStmt.setNull(4, Types.VARCHAR);
				pStmt.setNull(5, Types.VARCHAR);

				for (int i = 0; i < types.length; i++) {
					if ("TABLE".equalsIgnoreCase(types[i])) {
						pStmt.setString(3, "BASE TABLE");
					}

					if ("VIEW".equalsIgnoreCase(types[i])) {
						pStmt.setString(4, "VIEW");
					}

					if ("LOCAL TEMPORARY".equalsIgnoreCase(types[i])) {
						pStmt.setString(5, "TEMPORARY");
					}
				}
			}

			ResultSet rs = executeMetadataQuery(pStmt);

			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createTablesFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}
	
	public boolean gethasParametersView() {
		return this.hasParametersView;
	}


	@Override
	public ResultSet getVersionColumns(String catalog, String schema,
			String table) throws SQLException {

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				catalog = this.database;
			}
		}

		if (table == null) {
			throw SQLError.createSQLException("Table not specified.",
					SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
		}

		StringBuffer sqlBuf = new StringBuffer("SELECT NULL AS SCOPE, COLUMN_NAME, ");

		MysqlDefs.appendJdbcTypeMappingQuery(sqlBuf, "DATA_TYPE");
		sqlBuf.append(" AS DATA_TYPE, ");

		sqlBuf.append("COLUMN_TYPE AS TYPE_NAME, ");
		sqlBuf.append("CASE WHEN LCASE(DATA_TYPE)='date' THEN 10 WHEN LCASE(DATA_TYPE)='time' THEN 8 "
				+ "WHEN LCASE(DATA_TYPE)='datetime' THEN 19 WHEN LCASE(DATA_TYPE)='timestamp' THEN 19 "
				+ "WHEN CHARACTER_MAXIMUM_LENGTH IS NULL THEN NUMERIC_PRECISION WHEN CHARACTER_MAXIMUM_LENGTH > " 
				+ Integer.MAX_VALUE + " THEN " + Integer.MAX_VALUE + " ELSE CHARACTER_MAXIMUM_LENGTH END AS COLUMN_SIZE, ");
		sqlBuf.append(
				MysqlIO.getMaxBuf() + " AS BUFFER_LENGTH,"
				+ "NUMERIC_SCALE AS DECIMAL_DIGITS, "
				+ Integer.toString(java.sql.DatabaseMetaData.versionColumnNotPseudo) + " AS PSEUDO_COLUMN "
				+ "FROM INFORMATION_SCHEMA.COLUMNS "
				+ "WHERE TABLE_SCHEMA LIKE ? AND TABLE_NAME LIKE ?"
				+ " AND EXTRA LIKE '%on update CURRENT_TIMESTAMP%'");

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sqlBuf.toString());

			if (catalog != null) {
				pStmt.setString(1, catalog);
			} else {
				pStmt.setString(1, "%");
			}

			pStmt.setString(2, table);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(new Field[] {
					new Field("", "SCOPE", Types.SMALLINT, 5),
					new Field("", "COLUMN_NAME", Types.CHAR, 32),
					new Field("", "DATA_TYPE", Types.INTEGER, 5),
					new Field("", "TYPE_NAME", Types.CHAR, 16),
					new Field("", "COLUMN_SIZE", Types.INTEGER, 16),
					new Field("", "BUFFER_LENGTH", Types.INTEGER, 16),
					new Field("", "DECIMAL_DIGITS", Types.SMALLINT, 16),
					new Field("", "PSEUDO_COLUMN", Types.SMALLINT, 5)
			});

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	//
	// JDBC-4.0 functions that aren't reliant on Java6
	//

    /**
     * Retrieves a description of the given catalog's system or user 
     * function parameters and return type.
     *
     * <P>Only descriptions matching the schema,  function and
     * parameter name criteria are returned. They are ordered by
     * <code>FUNCTION_CAT</code>, <code>FUNCTION_SCHEM</code>,
     * <code>FUNCTION_NAME</code> and 
     * <code>SPECIFIC_ NAME</code>. Within this, the return value,
     * if any, is first. Next are the parameter descriptions in call
     * order. The column descriptions follow in column number order.
     *
     * <P>Each row in the <code>ResultSet</code> 
     * is a parameter description, column description or
     * return type description with the following fields:
     *  <OL>
     *  <LI><B>FUNCTION_CAT</B> String => function catalog (may be <code>null</code>)
     *	<LI><B>FUNCTION_SCHEM</B> String => function schema (may be <code>null</code>)
     *	<LI><B>FUNCTION_NAME</B> String => function name.  This is the name 
     * used to invoke the function
     *	<LI><B>COLUMN_NAME</B> String => column/parameter name 
     *	<LI><B>COLUMN_TYPE</B> Short => kind of column/parameter:
     *      <UL>
     *      <LI> functionColumnUnknown - nobody knows
     *      <LI> functionColumnIn - IN parameter
     *      <LI> functionColumnInOut - INOUT parameter
     *      <LI> functionColumnOut - OUT parameter
     *      <LI> functionColumnReturn - function return value
     *      <LI> functionColumnResult - Indicates that the parameter or column
     *  is a column in the <code>ResultSet</code>
     *      </UL>
     *  <LI><B>DATA_TYPE</B> int => SQL type from java.sql.Types
     *	<LI><B>TYPE_NAME</B> String => SQL type name, for a UDT type the
     *  type name is fully qualified
     *	<LI><B>PRECISION</B> int => precision
     *	<LI><B>LENGTH</B> int => length in bytes of data
     *	<LI><B>SCALE</B> short => scale -  null is returned for data types where  
     * SCALE is not applicable.
     *	<LI><B>RADIX</B> short => radix
     *	<LI><B>NULLABLE</B> short => can it contain NULL.
     *      <UL>
     *      <LI> functionNoNulls - does not allow NULL values
     *      <LI> functionNullable - allows NULL values
     *      <LI> functionNullableUnknown - nullability unknown
     *      </UL>
     *	<LI><B>REMARKS</B> String => comment describing column/parameter
     *	<LI><B>CHAR_OCTET_LENGTH</B> int  => the maximum length of binary 
     * and character based parameters or columns.  For any other datatype the returned value 
     * is a NULL
     *	<LI><B>ORDINAL_POSITION</B> int  => the ordinal position, starting 
     * from 1, for the input and output parameters. A value of 0
     * is returned if this row describes the function's return value. 
     * For result set columns, it is the
     * ordinal position of the column in the result set starting from 1.  
     *	<LI><B>IS_NULLABLE</B> String  => ISO rules are used to determine 
     * the nullability for a parameter or column.
     *       <UL>
     *       <LI> YES           --- if the parameter or column can include NULLs
     *       <LI> NO            --- if the parameter or column  cannot include NULLs
     *       <LI> empty string  --- if the nullability for the 
     * parameter  or column is unknown
     *       </UL>
     *	<LI><B>SPECIFIC_NAME</B> String  => the name which uniquely identifies 
     * this function within its schema.  This is a user specified, or DBMS
     * generated, name that may be different then the <code>FUNCTION_NAME</code> 
     * for example with overload functions
     *  </OL>
     * 
     * <p>The PRECISION column represents the specified column size for the given 
     * parameter or column. 
     * For numeric data, this is the maximum precision.  For character data, this is the length in characters. 
     * For datetime datatypes, this is the length in characters of the String representation (assuming the 
     * maximum allowed precision of the fractional seconds component). For binary data, this is the length in bytes.  For the ROWID datatype, 
     * this is the length in bytes. Null is returned for data types where the
     * column size is not applicable.
     * @param catalog a catalog name; must match the catalog name as it
     *        is stored in the database; "" retrieves those without a catalog;
     *        <code>null</code> means that the catalog name should not be used to narrow
     *        the search
     * @param schemaPattern a schema name pattern; must match the schema name
     *        as it is stored in the database; "" retrieves those without a schema;
     *        <code>null</code> means that the schema name should not be used to narrow
     *        the search
     * @param functionNamePattern a procedure name pattern; must match the
     *        function name as it is stored in the database 
     * @param columnNamePattern a parameter name pattern; must match the 
     * parameter or column name as it is stored in the database 
     * @return <code>ResultSet</code> - each row describes a 
     * user function parameter, column  or return type
     *
     * @exception SQLException if a database access error occurs
     * @see #getSearchStringEscape 
     * @since 1.6
     */
    public ResultSet getFunctionColumns(String catalog,
				  String schemaPattern,
				  String functionNamePattern, 
				  String columnNamePattern) throws SQLException {
		if (!this.hasParametersView) {
			return super.getFunctionColumns(catalog, schemaPattern, functionNamePattern, columnNamePattern);
		}
		
		if ((functionNamePattern == null)
				|| (functionNamePattern.length() == 0)) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				functionNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Procedure name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		String db = null;

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				db = this.database;
			}
		} else {
			db = catalog;
        }

		// FUNCTION_CAT
		// FUNCTION_SCHEM
		// FUNCTION_NAME
		// COLUMN_NAME
		// COLUMN_TYPE
		StringBuffer sqlBuf = new StringBuffer("SELECT SPECIFIC_SCHEMA AS FUNCTION_CAT, "
				+ "NULL AS `FUNCTION_SCHEM`, "
				+ "SPECIFIC_NAME AS `FUNCTION_NAME`, "
				+ "IFNULL(PARAMETER_NAME, '') AS `COLUMN_NAME`, "
				+ "CASE WHEN PARAMETER_MODE = 'IN' THEN " + getJDBC4FunctionConstant(JDBC4FunctionConstant.FUNCTION_COLUMN_IN)
					+ " WHEN PARAMETER_MODE = 'OUT' THEN " + getJDBC4FunctionConstant(JDBC4FunctionConstant.FUNCTION_COLUMN_OUT) 
					+ " WHEN PARAMETER_MODE = 'INOUT' THEN " + getJDBC4FunctionConstant(JDBC4FunctionConstant.FUNCTION_COLUMN_INOUT)
					+ " WHEN ORDINAL_POSITION = 0 THEN " + getJDBC4FunctionConstant(JDBC4FunctionConstant.FUNCTION_COLUMN_RETURN) 
					+ " ELSE " + getJDBC4FunctionConstant(JDBC4FunctionConstant.FUNCTION_COLUMN_UNKNOWN)
				+ " END AS `COLUMN_TYPE`, ");
		
		//DATA_TYPE
		MysqlDefs.appendJdbcTypeMappingQuery(sqlBuf, "DATA_TYPE");

		sqlBuf.append(" AS `DATA_TYPE`, ");

		// TYPE_NAME
		if (conn.getCapitalizeTypeNames()) {
			sqlBuf.append("UPPER(CASE WHEN LOCATE('unsigned', DATA_TYPE) != 0 AND LOCATE('unsigned', DATA_TYPE) = 0 THEN CONCAT(DATA_TYPE, ' unsigned') ELSE DATA_TYPE END) AS `TYPE_NAME`,");
		} else {
			sqlBuf.append("CASE WHEN LOCATE('unsigned', DATA_TYPE) != 0 AND LOCATE('unsigned', DATA_TYPE) = 0 THEN CONCAT(DATA_TYPE, ' unsigned') ELSE DATA_TYPE END AS `TYPE_NAME`,");
		}

		// PRECISION int => precision
		sqlBuf.append("NUMERIC_PRECISION AS `PRECISION`, ");
		// LENGTH int => length in bytes of data
		sqlBuf
				.append("CASE WHEN LCASE(DATA_TYPE)='date' THEN 10 WHEN LCASE(DATA_TYPE)='time' THEN 8 WHEN LCASE(DATA_TYPE)='datetime' THEN 19 WHEN LCASE(DATA_TYPE)='timestamp' THEN 19 WHEN CHARACTER_MAXIMUM_LENGTH IS NULL THEN NUMERIC_PRECISION WHEN CHARACTER_MAXIMUM_LENGTH > " 
						+ Integer.MAX_VALUE + " THEN " + Integer.MAX_VALUE + " ELSE CHARACTER_MAXIMUM_LENGTH END AS LENGTH, ");
		
		// SCALE short => scale
		sqlBuf.append("NUMERIC_SCALE AS `SCALE`, ");
		// RADIX short => radix
		sqlBuf.append("10 AS RADIX,");
		// NULLABLE
		// REMARKS
		// CHAR_OCTET_LENGTH *
		// ORDINAL_POSITION *
		// IS_NULLABLE *
		// SPECIFIC_NAME *
		sqlBuf.append(getJDBC4FunctionConstant(JDBC4FunctionConstant.FUNCTION_NULLABLE) + " AS `NULLABLE`, "
				+ " NULL AS `REMARKS`, "
				+ "CHARACTER_OCTET_LENGTH AS `CHAR_OCTET_LENGTH`, "
				+ " ORDINAL_POSITION, "
				+ "'YES' AS `IS_NULLABLE`, "
				+ "SPECIFIC_NAME "
				+ "FROM INFORMATION_SCHEMA.PARAMETERS WHERE "
				+ "SPECIFIC_SCHEMA LIKE ? AND SPECIFIC_NAME LIKE ? AND (PARAMETER_NAME LIKE ? OR PARAMETER_NAME IS NULL) "
				+ "AND ROUTINE_TYPE='FUNCTION' ORDER BY SPECIFIC_SCHEMA, SPECIFIC_NAME, ORDINAL_POSITION");

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sqlBuf.toString());
			
			if (db != null) {
				pStmt.setString(1, db);
			} else {
				pStmt.setString(1, "%");
			}
			
			pStmt.setString(2, functionNamePattern);
			pStmt.setString(3, columnNamePattern);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(createFunctionColumnsFields());

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Getter to JDBC4 DatabaseMetaData.function* constants.
	 * This method must be overridden by JDBC4 subclasses. this implementation should never be called.
	 * 
	 * @param constant
	 *            the constant id from DatabaseMetaData fields to return.
	 * 
	 * @return 0
	 */
	protected int getJDBC4FunctionConstant(JDBC4FunctionConstant constant) {
		return 0;
	}

    /**
     * Retrieves a description of the  system and user functions available 
     * in the given catalog.
     * <P>
     * Only system and user function descriptions matching the schema and
     * function name criteria are returned.  They are ordered by
     * <code>FUNCTION_CAT</code>, <code>FUNCTION_SCHEM</code>,
     * <code>FUNCTION_NAME</code> and 
     * <code>SPECIFIC_ NAME</code>.
     *
     * <P>Each function description has the the following columns:
     *  <OL>
     *	<LI><B>FUNCTION_CAT</B> String => function catalog (may be <code>null</code>)
     *	<LI><B>FUNCTION_SCHEM</B> String => function schema (may be <code>null</code>)
     *	<LI><B>FUNCTION_NAME</B> String => function name.  This is the name 
     * used to invoke the function
     *	<LI><B>REMARKS</B> String => explanatory comment on the function
     * <LI><B>FUNCTION_TYPE</B> short => kind of function:
     *      <UL>
     *      <LI>functionResultUnknown - Cannot determine if a return value
     *       or table will be returned
     *      <LI> functionNoTable- Does not return a table
     *      <LI> functionReturnsTable - Returns a table
     *      </UL>
     *	<LI><B>SPECIFIC_NAME</B> String  => the name which uniquely identifies 
     *  this function within its schema.  This is a user specified, or DBMS
     * generated, name that may be different then the <code>FUNCTION_NAME</code> 
     * for example with overload functions
     *  </OL>
     * <p>
     * A user may not have permission to execute any of the functions that are
     * returned by <code>getFunctions</code>
     *
     * @param catalog a catalog name; must match the catalog name as it
     *        is stored in the database; "" retrieves those without a catalog;
     *        <code>null</code> means that the catalog name should not be used to narrow
     *        the search
     * @param schemaPattern a schema name pattern; must match the schema name
     *        as it is stored in the database; "" retrieves those without a schema;
     *        <code>null</code> means that the schema name should not be used to narrow
     *        the search
     * @param functionNamePattern a function name pattern; must match the
     *        function name as it is stored in the database 
     * @return <code>ResultSet</code> - each row is a function description 
     * @exception SQLException if a database access error occurs
     * @see #getSearchStringEscape 
     * @since 1.6
     */
	public java.sql.ResultSet getFunctions(String catalog, String schemaPattern,
		    String functionNamePattern) throws SQLException {

		if ((functionNamePattern == null)
				|| (functionNamePattern.length() == 0)) {
			if (this.conn.getNullNamePatternMatchesAll()) {
				functionNamePattern = "%";
			} else {
				throw SQLError.createSQLException(
						"Function name pattern can not be NULL or empty.",
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
			}
		}

		String db = null;

		if (catalog == null) {
			if (this.conn.getNullCatalogMeansCurrent()) {
				db = this.database;
			}
		}  else {
			db = catalog;
		}

		String sql = "SELECT ROUTINE_SCHEMA AS FUNCTION_CAT, NULL AS FUNCTION_SCHEM, "
				+ "ROUTINE_NAME AS FUNCTION_NAME, ROUTINE_COMMENT AS REMARKS, " + getJDBC4FunctionNoTableConstant()
				+ " AS FUNCTION_TYPE, ROUTINE_NAME AS SPECIFIC_NAME FROM INFORMATION_SCHEMA.ROUTINES "
				+ "WHERE ROUTINE_TYPE LIKE 'FUNCTION' AND ROUTINE_SCHEMA LIKE ? AND "
				+ "ROUTINE_NAME LIKE ? ORDER BY FUNCTION_CAT, FUNCTION_SCHEM, FUNCTION_NAME, SPECIFIC_NAME";

		java.sql.PreparedStatement pStmt = null;

		try {
			pStmt = prepareMetaDataSafeStatement(sql);
			
			pStmt.setString(1, db != null ? db : "%");
			pStmt.setString(2, functionNamePattern);

			ResultSet rs = executeMetadataQuery(pStmt);
			((com.mysql.jdbc.ResultSetInternalMethods) rs).redefineFieldsForDBMD(new Field[] {
					new Field("", "FUNCTION_CAT", Types.CHAR, 255),
					new Field("", "FUNCTION_SCHEM", Types.CHAR, 255),
					new Field("", "FUNCTION_NAME", Types.CHAR, 255),
					new Field("", "REMARKS", Types.CHAR, 255),
					new Field("", "FUNCTION_TYPE", Types.SMALLINT, 6),
					new Field("", "SPECIFIC_NAME", Types.CHAR, 255)
					});

			return rs;
		} finally {
			if (pStmt != null) {
				pStmt.close();
			}
		}
	}

	/**
	 * Getter to JDBC4 DatabaseMetaData.functionNoTable constant.
	 * This method must be overridden by JDBC4 subclasses. this implementation should never be called.
	 *
	 * @return 0
	 */
	protected int getJDBC4FunctionNoTableConstant() {
		return 0;
	}
}
