/* Copyright (C) 2002-2004 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation. There are special exceptions to the terms and conditions of the GPL as it is applied to this software. View the full text of the exception in file EXCEPTIONS-CONNECTOR-J in the directory of this software distribution. 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package com.mysql.jdbc; import java.sql.SQLException; import java.sql.Types; /** * A ResultSetMetaData object can be used to find out about the types and * properties of the columns in a ResultSet * * @author Mark Matthews * @version $Id: ResultSetMetaData.java,v 1.12.4.21 2004/12/09 22:02:19 mmatthew Exp $ * * @see java.sql.ResultSetMetaData */ public class ResultSetMetaData implements java.sql.ResultSetMetaData { Field[] fields; /** * Initialise for a result with a tuple set and a field descriptor set * * @param fields the array of field descriptors */ public ResultSetMetaData(Field[] fields) { this.fields = fields; } /** * Is the column automatically numbered (and thus read-only) MySQL * Auto-increment columns are not read only, so to conform to the spec, * this method returns false. * * @param column the first column is 1, the second is 2... * * @return true if so * * @throws SQLException if a database access error occurs */ public boolean isAutoIncrement(int column) throws SQLException { Field f = getField(column); return f.isAutoIncrement(); } /** * Does a column's case matter? * * @param column the first column is 1, the second is 2... * * @return true if so * * @throws java.sql.SQLException if a database access error occurs */ public boolean isCaseSensitive(int column) throws java.sql.SQLException { Field field = getField(column); int sqlType = field.getSQLType(); switch (sqlType) { case Types.BIT: case Types.TINYINT: case Types.SMALLINT: case Types.INTEGER: case Types.BIGINT: case Types.FLOAT: case Types.REAL: case Types.DOUBLE: case Types.DATE: case Types.TIME: case Types.TIMESTAMP: return false; case Types.CHAR: case Types.VARCHAR: case Types.LONGVARCHAR: if (field.isBinary()) { return true; } String collationName = field.getCollation(); return ((collationName != null) && !collationName.endsWith("_ci")); default: return true; } } /** * What's a column's table's catalog name? * * @param column the first column is 1, the second is 2... * * @return catalog name, or "" if not applicable * * @throws SQLException if a database access error occurs */ public String getCatalogName(int column) throws SQLException { Field f = getField(column); String database = f.getDatabaseName(); return (database == null) ? "" : database; //$NON-NLS-1$ } /** * What's the Java character encoding name for the given column? * * @param column the first column is 1, the second is 2, etc. * * @return the Java character encoding name for the given column, or null * if no Java character encoding maps to the MySQL character set * for the given column. * * @throws SQLException if an invalid column index is given. */ public String getColumnCharacterEncoding(int column) throws SQLException { String mysqlName = getColumnCharacterSet(column); String javaName = null; if (mysqlName != null) { javaName = (String) CharsetMapping.MYSQL_TO_JAVA_CHARSET_MAP.get(mysqlName); } return javaName; } /** * What's the MySQL character set name for the given column? * * @param column the first column is 1, the second is 2, etc. * * @return the MySQL character set name for the given column * * @throws SQLException if an invalid column index is given. */ public String getColumnCharacterSet(int column) throws SQLException { return getField(column).getCharacterSet(); } //--------------------------JDBC 2.0----------------------------------- /** * JDBC 2.0 * *

* Return the fully qualified name of the Java class whose instances are * manufactured if ResultSet.getObject() is called to retrieve a value * from the column. ResultSet.getObject() may return a subClass of the * class returned by this method. *

* * @param column the column number to retrieve information for * * @return the fully qualified name of the Java class whose instances are * manufactured if ResultSet.getObject() is called to retrieve a * value from the column. * * @throws SQLException if an error occurs */ public String getColumnClassName(int column) throws SQLException { Field f = getField(column); // From JDBC-3.0 spec, Table B-3 // // JDBC Type Java Object Type // // CHAR String // VARCHAR String // LONGVARCHAR String // NUMERIC java.math.BigDecimal // DECIMAL java.math.BigDecimal // BIT Boolean // BOOLEAN Boolean // TINYINT Integer // SMALLINT Integer // INTEGER Integer // BIGINT Long // REAL Float // FLOAT Double // DOUBLE Double // BINARY byte[] // VARBINARY byte[] // LONGVARBINARY byte[] // DATE java.sql.Date // TIME java.sql.Time // TIMESTAMP java.sql.Timestamp // DISTINCT Object type of underlying type // CLOB Clob // BLOB Blob // ARRAY Array // STRUCT Struct or SQLData // REF Ref // DATALINK java.net.URL // JAVA_OBJECT underlying Java class switch (f.getSQLType()) { case Types.BIT: case Types.BOOLEAN: return "java.lang.Boolean"; //$NON-NLS-1$ case Types.TINYINT: if (!f.isUnsigned()) { return "java.lang.Integer"; //$NON-NLS-1$ } return "java.lang.Integer"; //$NON-NLS-1$ case Types.SMALLINT: if (!f.isUnsigned()) { return "java.lang.Integer"; //$NON-NLS-1$ } return "java.lang.Integer"; //$NON-NLS-1$ case Types.INTEGER: if (!f.isUnsigned()) { return "java.lang.Integer"; //$NON-NLS-1$ } return "java.lang.Long"; //$NON-NLS-1$ case Types.BIGINT: if (!f.isUnsigned()) { return "java.lang.Long"; //$NON-NLS-1$ } return "java.math.BigInteger"; //$NON-NLS-1$ case Types.DECIMAL: case Types.NUMERIC: return "java.math.BigDecimal"; //$NON-NLS-1$ case Types.REAL: return "java.lang.Float"; //$NON-NLS-1$ case Types.FLOAT: case Types.DOUBLE: return "java.lang.Double"; //$NON-NLS-1$ case Types.CHAR: case Types.VARCHAR: case Types.LONGVARCHAR: return "java.lang.String"; //$NON-NLS-1$ case Types.BINARY: case Types.VARBINARY: case Types.LONGVARBINARY: if (!f.isBlob()) { return "java.lang.String"; //$NON-NLS-1$ } else if (!f.isBinary()) { return "java.lang.String"; //$NON-NLS-1$ } else { return "[B"; //$NON-NLS-1$ } case Types.DATE: return "java.sql.Date"; //$NON-NLS-1$ case Types.TIME: return "java.sql.Time"; //$NON-NLS-1$ case Types.TIMESTAMP: return "java.sql.Timestamp"; //$NON-NLS-1$ default: return "java.lang.Object"; //$NON-NLS-1$ } } /** * Whats the number of columns in the ResultSet? * * @return the number * * @throws SQLException if a database access error occurs */ public int getColumnCount() throws SQLException { return this.fields.length; } /** * What is the column's normal maximum width in characters? * * @param column the first column is 1, the second is 2, etc. * * @return the maximum width * * @throws SQLException if a database access error occurs */ public int getColumnDisplaySize(int column) throws SQLException { Field f = getField(column); int lengthInBytes = f.getLength(); return lengthInBytes / f.getMaxBytesPerCharacter(); } /** * What is the suggested column title for use in printouts and displays? * * @param column the first column is 1, the second is 2, etc. * * @return the column label * * @throws SQLException if a database access error occurs */ public String getColumnLabel(int column) throws SQLException { return getColumnName(column); } /** * What's a column's name? * * @param column the first column is 1, the second is 2, etc. * * @return the column name * * @throws SQLException if a databvase access error occurs */ public String getColumnName(int column) throws SQLException { return getField(column).getName(); } /** * What is a column's SQL Type? (java.sql.Type int) * * @param column the first column is 1, the second is 2, etc. * * @return the java.sql.Type value * * @throws SQLException if a database access error occurs * * @see java.sql.Types */ public int getColumnType(int column) throws SQLException { return getField(column).getSQLType(); } /** * Whats is the column's data source specific type name? * * @param column the first column is 1, the second is 2, etc. * * @return the type name * * @throws SQLException if a database access error occurs */ public String getColumnTypeName(int column) throws java.sql.SQLException { Field field = getField(column); int mysqlType = field.getMysqlType(); switch (mysqlType) { case MysqlDefs.FIELD_TYPE_DECIMAL: return field.isUnsigned() ? "DECIMAL UNSIGNED" : "DECIMAL"; case MysqlDefs.FIELD_TYPE_TINY: return field.isUnsigned() ? "TINYINT UNSIGNED" : "TINYINT"; case MysqlDefs.FIELD_TYPE_SHORT: return field.isUnsigned() ? "SMALLINT UNSIGNED" : "SMALLINT"; case MysqlDefs.FIELD_TYPE_LONG: return field.isUnsigned() ? "INTEGER UNSIGNED" : "INTEGER"; case MysqlDefs.FIELD_TYPE_FLOAT: return field.isUnsigned() ? "FLOAT UNSIGNED" : "FLOAT"; case MysqlDefs.FIELD_TYPE_DOUBLE: return field.isUnsigned() ? "DOUBLE UNSIGNED" : "DOUBLE"; case MysqlDefs.FIELD_TYPE_NULL: return "NULL"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_TIMESTAMP: return "TIMESTAMP"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_LONGLONG: return field.isUnsigned() ? "BIGINT UNSIGNED" : "BIGINT"; case MysqlDefs.FIELD_TYPE_INT24: return field.isUnsigned() ? "MEDIUMINT UNSIGNED" : "MEDIUMINT"; case MysqlDefs.FIELD_TYPE_DATE: return "DATE"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_TIME: return "TIME"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_DATETIME: return "DATETIME"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_TINY_BLOB: return "TINYBLOB"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_MEDIUM_BLOB: return "MEDIUMBLOB"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_LONG_BLOB: return "LONGBLOB"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_BLOB: if (getField(column).isBinary()) { return "BLOB";//$NON-NLS-1$ } return "TEXT";//$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_VARCHAR: return "VARCHAR"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_VAR_STRING: return "VARCHAR"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_STRING: return "CHAR"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_ENUM: return "ENUM"; //$NON-NLS-1$ case MysqlDefs.FIELD_TYPE_YEAR: return "YEAR"; //$NON_NLS-1$ case MysqlDefs.FIELD_TYPE_SET: return "SET"; //$NON-NLS-1$ default: return "UNKNOWN"; //$NON-NLS-1$ } } /** * Is the column a cash value? * * @param column the first column is 1, the second is 2... * * @return true if its a cash column * * @throws SQLException if a database access error occurs */ public boolean isCurrency(int column) throws SQLException { return false; } /** * Will a write on this column definately succeed? * * @param column the first column is 1, the second is 2, etc.. * * @return true if so * * @throws SQLException if a database access error occurs */ public boolean isDefinitelyWritable(int column) throws SQLException { return isWritable(column); } /** * Can you put a NULL in this column? * * @param column the first column is 1, the second is 2... * * @return one of the columnNullable values * * @throws SQLException if a database access error occurs */ public int isNullable(int column) throws SQLException { if (!getField(column).isNotNull()) { return java.sql.ResultSetMetaData.columnNullable; } return java.sql.ResultSetMetaData.columnNoNulls; } /** * What is a column's number of decimal digits. * * @param column the first column is 1, the second is 2... * * @return the precision * * @throws SQLException if a database access error occurs */ public int getPrecision(int column) throws SQLException { Field f = getField(column); if (isDecimalType(f.getSQLType())) { if (f.getDecimals() > 0) { return f.getLength() - 1 + f.getPrecisionAdjustFactor(); } return f.getLength() + f.getPrecisionAdjustFactor(); } switch (f.getMysqlType()) { case MysqlDefs.FIELD_TYPE_TINY_BLOB: case MysqlDefs.FIELD_TYPE_BLOB: case MysqlDefs.FIELD_TYPE_MEDIUM_BLOB: case MysqlDefs.FIELD_TYPE_LONG_BLOB: return f.getLength(); // this may change in the future // for now, the server only // returns FIELD_TYPE_BLOB for _all_ // BLOB types, but varying lengths // indicating the _maximum_ size // for each BLOB type. default: return f.getLength(); } } /** * Is the column definitely not writable? * * @param column the first column is 1, the second is 2, etc. * * @return true if so * * @throws SQLException if a database access error occurs */ public boolean isReadOnly(int column) throws SQLException { return getField(column).isReadOnly(); } /** * What is a column's number of digits to the right of the decimal point? * * @param column the first column is 1, the second is 2... * * @return the scale * * @throws SQLException if a database access error occurs */ public int getScale(int column) throws SQLException { Field f = getField(column); if (isDecimalType(f.getSQLType())) { return f.getDecimals(); } return 0; } /** * What is a column's table's schema? This relies on us knowing the table * name. The JDBC specification allows us to return "" if this is not * applicable. * * @param column the first column is 1, the second is 2... * * @return the Schema * * @throws SQLException if a database access error occurs */ public String getSchemaName(int column) throws SQLException { return ""; //$NON-NLS-1$ } /** * Can the column be used in a WHERE clause? Basically for this, I split * the functions into two types: recognised types (which are always * useable), and OTHER types (which may or may not be useable). The OTHER * types, for now, I will assume they are useable. We should really query * the catalog to see if they are useable. * * @param column the first column is 1, the second is 2... * * @return true if they can be used in a WHERE clause * * @throws SQLException if a database access error occurs */ public boolean isSearchable(int column) throws SQLException { return true; } /** * Is the column a signed number? * * @param column the first column is 1, the second is 2... * * @return true if so * * @throws SQLException if a database access error occurs */ public boolean isSigned(int column) throws SQLException { Field f = getField(column); int sqlType = f.getSQLType(); switch (sqlType) { case Types.TINYINT: case Types.SMALLINT: case Types.INTEGER: case Types.BIGINT: case Types.FLOAT: case Types.REAL: case Types.DOUBLE: case Types.NUMERIC: case Types.DECIMAL: return !f.isUnsigned(); case Types.DATE: case Types.TIME: case Types.TIMESTAMP: return false; default: return false; } } /** * Whats a column's table's name? * * @param column the first column is 1, the second is 2... * * @return column name, or "" if not applicable * * @throws SQLException if a database access error occurs */ public String getTableName(int column) throws SQLException { return getField(column).getTableName(); } /** * Is it possible for a write on the column to succeed? * * @param column the first column is 1, the second is 2, etc. * * @return true if so * * @throws SQLException if a database access error occurs */ public boolean isWritable(int column) throws SQLException { return !isReadOnly(column); } /** * Returns a string representation of this object * * @return ... */ public String toString() { StringBuffer toStringBuf = new StringBuffer(); toStringBuf.append(super.toString()); toStringBuf.append(" - Field level information: "); //$NON-NLS-1$ for (int i = 0; i < this.fields.length; i++) { toStringBuf.append("\n\t"); //$NON-NLS-1$ toStringBuf.append(this.fields[i].toString()); } return toStringBuf.toString(); } // ********************************************************************* // // END OF PUBLIC INTERFACE // // ********************************************************************* /** * Returns the field instance for the given column index * * @param columnIndex the column number to retrieve a field instance for * * @return the field instance for the given column index * * @throws SQLException if an error occurs */ protected Field getField(int columnIndex) throws SQLException { if ((columnIndex < 1) || (columnIndex > this.fields.length)) { throw new SQLException(Messages.getString("ResultSetMetaData.46"), //$NON-NLS-1$ SQLError.SQL_STATE_INVALID_COLUMN_NUMBER); } return this.fields[columnIndex - 1]; } /** * Checks if the SQL Type is a Decimal/Number Type * * @param type SQL Type * * @return ... */ private static final boolean isDecimalType(int type) { switch (type) { case Types.BIT: case Types.TINYINT: case Types.SMALLINT: case Types.INTEGER: case Types.BIGINT: case Types.FLOAT: case Types.REAL: case Types.DOUBLE: case Types.NUMERIC: case Types.DECIMAL: return true; } return false; } }