Back to index...

	/*
	* Copyright (c) 1996, 2005, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.sql;

	/**
	* An object that can be used to get information about the types
	* and properties of the columns in a <code>ResultSet</code> object.
	* The following code fragment creates the <code>ResultSet</code> object rs,
	* creates the <code>ResultSetMetaData</code> object rsmd, and uses rsmd
	* to find out how many columns rs has and whether the first column in rs
	* can be used in a <code>WHERE</code> clause.
	* <PRE>
	*
	* ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM TABLE2");
	* ResultSetMetaData rsmd = rs.getMetaData();
	* int numberOfColumns = rsmd.getColumnCount();
	* boolean b = rsmd.isSearchable(1);
	*
	* </PRE>
	*/

	public interface ResultSetMetaData extends Wrapper {

	/**
	* Returns the number of columns in this <code>ResultSet</code> object.
	*
	* @return the number of columns
	* @exception SQLException if a database access error occurs
	*/
	int getColumnCount() throws SQLException;

	/**
	* Indicates whether the designated column is automatically numbered.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isAutoIncrement(int column) throws SQLException;

	/**
	* Indicates whether a column's case matters.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isCaseSensitive(int column) throws SQLException;

	/**
	* Indicates whether the designated column can be used in a where clause.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isSearchable(int column) throws SQLException;

	/**
	* Indicates whether the designated column is a cash value.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isCurrency(int column) throws SQLException;

	/**
	* Indicates the nullability of values in the designated column.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return the nullability status of the given column; one of <code>columnNoNulls</code>,
	* <code>columnNullable</code> or <code>columnNullableUnknown</code>
	* @exception SQLException if a database access error occurs
	*/
	int isNullable(int column) throws SQLException;

	/**
	* The constant indicating that a
	* column does not allow <code>NULL</code> values.
	*/
	int columnNoNulls = 0;

	/**
	* The constant indicating that a
	* column allows <code>NULL</code> values.
	*/
	int columnNullable = 1;

	/**
	* The constant indicating that the
	* nullability of a column's values is unknown.
	*/
	int columnNullableUnknown = 2;

	/**
	* Indicates whether values in the designated column are signed numbers.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isSigned(int column) throws SQLException;

	/**
	* Indicates the designated column's normal maximum width in characters.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return the normal maximum number of characters allowed as the width
	* of the designated column
	* @exception SQLException if a database access error occurs
	*/
	int getColumnDisplaySize(int column) throws SQLException;

	/**
	* Gets the designated column's suggested title for use in printouts and
	* displays. The suggested title is usually specified by the SQL <code>AS</code>
	* clause. If a SQL <code>AS</code> is not specified, the value returned from
	* <code>getColumnLabel</code> will be the same as the value returned by the
	* <code>getColumnName</code> method.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return the suggested column title
	* @exception SQLException if a database access error occurs
	*/
	String getColumnLabel(int column) throws SQLException;

	/**
	* Get the designated column's name.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return column name
	* @exception SQLException if a database access error occurs
	*/
	String getColumnName(int column) throws SQLException;

	/**
	* Get the designated column's table's schema.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return schema name or "" if not applicable
	* @exception SQLException if a database access error occurs
	*/
	String getSchemaName(int column) throws SQLException;

	/**
	* Get the designated column's specified column size.
	* 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. 0 is returned for data types where the
	* column size is not applicable.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return precision
	* @exception SQLException if a database access error occurs
	*/
	int getPrecision(int column) throws SQLException;

	/**
	* Gets the designated column's number of digits to right of the decimal point.
	* 0 is returned for data types where the scale is not applicable.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return scale
	* @exception SQLException if a database access error occurs
	*/
	int getScale(int column) throws SQLException;

	/**
	* Gets the designated column's table name.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return table name or "" if not applicable
	* @exception SQLException if a database access error occurs
	*/
	String getTableName(int column) throws SQLException;

	/**
	* Gets the designated column's table's catalog name.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return the name of the catalog for the table in which the given column
	* appears or "" if not applicable
	* @exception SQLException if a database access error occurs
	*/
	String getCatalogName(int column) throws SQLException;

	/**
	* Retrieves the designated column's SQL type.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return SQL type from java.sql.Types
	* @exception SQLException if a database access error occurs
	* @see Types
	*/
	int getColumnType(int column) throws SQLException;

	/**
	* Retrieves the designated column's database-specific type name.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return type name used by the database. If the column type is
	* a user-defined type, then a fully-qualified type name is returned.
	* @exception SQLException if a database access error occurs
	*/
	String getColumnTypeName(int column) throws SQLException;

	/**
	* Indicates whether the designated column is definitely not writable.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isReadOnly(int column) throws SQLException;

	/**
	* Indicates whether it is possible for a write on the designated column to succeed.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isWritable(int column) throws SQLException;

	/**
	* Indicates whether a write on the designated column will definitely succeed.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return <code>true</code> if so; <code>false</code> otherwise
	* @exception SQLException if a database access error occurs
	*/
	boolean isDefinitelyWritable(int column) throws SQLException;

	//--------------------------JDBC 2.0-----------------------------------

	/**
	* <p>Returns the fully-qualified name of the Java class whose instances
	* are manufactured if the method <code>ResultSet.getObject</code>
	* is called to retrieve a value
	* from the column. <code>ResultSet.getObject</code> may return a subclass of the
	* class returned by this method.
	*
	* @param column the first column is 1, the second is 2, ...
	* @return the fully-qualified name of the class in the Java programming
	* language that would be used by the method
	* <code>ResultSet.getObject</code> to retrieve the value in the specified
	* column. This is the class name used for custom mapping.
	* @exception SQLException if a database access error occurs
	* @since 1.2
	*/
	String getColumnClassName(int column) throws SQLException;
	}

Back to index...