/*
* 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;
}