Java tutorial
/* * Copyright (c) 2000, 2006, 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 for each parameter marker in a * <code>PreparedStatement</code> object. For some queries and driver * implementations, the data that would be returned by a <code>ParameterMetaData</code> * object may not be available until the <code>PreparedStatement</code> has * been executed. *<p> *Some driver implementations may not be able to provide information about the *types and properties for each parameter marker in a <code>CallableStatement</code> *object. * * @since 1.4 */ public interface ParameterMetaData extends Wrapper { /** * Retrieves the number of parameters in the <code>PreparedStatement</code> * object for which this <code>ParameterMetaData</code> object contains * information. * * @return the number of parameters * @exception SQLException if a database access error occurs * @since 1.4 */ int getParameterCount() throws SQLException; /** * Retrieves whether null values are allowed in the designated parameter. * * @param param the first parameter is 1, the second is 2, ... * @return the nullability status of the given parameter; one of * <code>ParameterMetaData.parameterNoNulls</code>, * <code>ParameterMetaData.parameterNullable</code>, or * <code>ParameterMetaData.parameterNullableUnknown</code> * @exception SQLException if a database access error occurs * @since 1.4 */ int isNullable(int param) throws SQLException; /** * The constant indicating that a * parameter will not allow <code>NULL</code> values. */ int parameterNoNulls = 0; /** * The constant indicating that a * parameter will allow <code>NULL</code> values. */ int parameterNullable = 1; /** * The constant indicating that the * nullability of a parameter is unknown. */ int parameterNullableUnknown = 2; /** * Retrieves whether values for the designated parameter can be signed numbers. * * @param param the first parameter is 1, the second is 2, ... * @return <code>true</code> if so; <code>false</code> otherwise * @exception SQLException if a database access error occurs * @since 1.4 */ boolean isSigned(int param) throws SQLException; /** * Retrieves the designated parameter's specified column size. * * <P>The returned value represents the maximum column size for the given parameter. * 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 param the first parameter is 1, the second is 2, ... * @return precision * @exception SQLException if a database access error occurs * @since 1.4 */ int getPrecision(int param) throws SQLException; /** * Retrieves the designated parameter's number of digits to right of the decimal point. * 0 is returned for data types where the scale is not applicable. * * @param param the first parameter is 1, the second is 2, ... * @return scale * @exception SQLException if a database access error occurs * @since 1.4 */ int getScale(int param) throws SQLException; /** * Retrieves the designated parameter's SQL type. * * @param param the first parameter is 1, the second is 2, ... * @return SQL type from <code>java.sql.Types</code> * @exception SQLException if a database access error occurs * @since 1.4 * @see Types */ int getParameterType(int param) throws SQLException; /** * Retrieves the designated parameter's database-specific type name. * * @param param the first parameter is 1, the second is 2, ... * @return type the name used by the database. If the parameter type is * a user-defined type, then a fully-qualified type name is returned. * @exception SQLException if a database access error occurs * @since 1.4 */ String getParameterTypeName(int param) throws SQLException; /** * Retrieves the fully-qualified name of the Java class whose instances * should be passed to the method <code>PreparedStatement.setObject</code>. * * @param param the first parameter 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>PreparedStatement.setObject</code> to set the value * in the specified parameter. This is the class name used * for custom mapping. * @exception SQLException if a database access error occurs * @since 1.4 */ String getParameterClassName(int param) throws SQLException; /** * The constant indicating that the mode of the parameter is unknown. */ int parameterModeUnknown = 0; /** * The constant indicating that the parameter's mode is IN. */ int parameterModeIn = 1; /** * The constant indicating that the parameter's mode is INOUT. */ int parameterModeInOut = 2; /** * The constant indicating that the parameter's mode is OUT. */ int parameterModeOut = 4; /** * Retrieves the designated parameter's mode. * * @param param the first parameter is 1, the second is 2, ... * @return mode of the parameter; one of * <code>ParameterMetaData.parameterModeIn</code>, * <code>ParameterMetaData.parameterModeOut</code>, or * <code>ParameterMetaData.parameterModeInOut</code> * <code>ParameterMetaData.parameterModeUnknown</code>. * @exception SQLException if a database access error occurs * @since 1.4 */ int getParameterMode(int param) throws SQLException; }