1 /* 2 * Copyright (c) 2000, 2006, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.sql; 27 28 /** 29 * An object that can be used to get information about the types 30 * and properties for each parameter marker in a 31 * <code>PreparedStatement</code> object. For some queries and driver 32 * implementations, the data that would be returned by a <code>ParameterMetaData</code> 33 * object may not be available until the <code>PreparedStatement</code> has 34 * been executed. 35 *<p> 36 *Some driver implementations may not be able to provide information about the 37 *types and properties for each parameter marker in a <code>CallableStatement</code> 38 *object. 39 * 40 * @since 1.4 41 */ 42 43 public interface ParameterMetaData extends Wrapper { 44 45 /** 46 * Retrieves the number of parameters in the <code>PreparedStatement</code> 47 * object for which this <code>ParameterMetaData</code> object contains 48 * information. 49 * 50 * @return the number of parameters 51 * @exception SQLException if a database access error occurs 52 * @since 1.4 53 */ getParameterCount()54 int getParameterCount() throws SQLException; 55 56 /** 57 * Retrieves whether null values are allowed in the designated parameter. 58 * 59 * @param param the first parameter is 1, the second is 2, ... 60 * @return the nullability status of the given parameter; one of 61 * <code>ParameterMetaData.parameterNoNulls</code>, 62 * <code>ParameterMetaData.parameterNullable</code>, or 63 * <code>ParameterMetaData.parameterNullableUnknown</code> 64 * @exception SQLException if a database access error occurs 65 * @since 1.4 66 */ isNullable(int param)67 int isNullable(int param) throws SQLException; 68 69 /** 70 * The constant indicating that a 71 * parameter will not allow <code>NULL</code> values. 72 */ 73 int parameterNoNulls = 0; 74 75 /** 76 * The constant indicating that a 77 * parameter will allow <code>NULL</code> values. 78 */ 79 int parameterNullable = 1; 80 81 /** 82 * The constant indicating that the 83 * nullability of a parameter is unknown. 84 */ 85 int parameterNullableUnknown = 2; 86 87 /** 88 * Retrieves whether values for the designated parameter can be signed numbers. 89 * 90 * @param param the first parameter is 1, the second is 2, ... 91 * @return <code>true</code> if so; <code>false</code> otherwise 92 * @exception SQLException if a database access error occurs 93 * @since 1.4 94 */ isSigned(int param)95 boolean isSigned(int param) throws SQLException; 96 97 /** 98 * Retrieves the designated parameter's specified column size. 99 * 100 * <P>The returned value represents the maximum column size for the given parameter. 101 * For numeric data, this is the maximum precision. For character data, this is the length in characters. 102 * For datetime datatypes, this is the length in characters of the String representation (assuming the 103 * maximum allowed precision of the fractional seconds component). For binary data, this is the length in bytes. For the ROWID datatype, 104 * this is the length in bytes. 0 is returned for data types where the 105 * column size is not applicable. 106 * 107 * @param param the first parameter is 1, the second is 2, ... 108 * @return precision 109 * @exception SQLException if a database access error occurs 110 * @since 1.4 111 */ getPrecision(int param)112 int getPrecision(int param) throws SQLException; 113 114 /** 115 * Retrieves the designated parameter's number of digits to right of the decimal point. 116 * 0 is returned for data types where the scale is not applicable. 117 * 118 * @param param the first parameter is 1, the second is 2, ... 119 * @return scale 120 * @exception SQLException if a database access error occurs 121 * @since 1.4 122 */ getScale(int param)123 int getScale(int param) throws SQLException; 124 125 /** 126 * Retrieves the designated parameter's SQL type. 127 * 128 * @param param the first parameter is 1, the second is 2, ... 129 * @return SQL type from <code>java.sql.Types</code> 130 * @exception SQLException if a database access error occurs 131 * @since 1.4 132 * @see Types 133 */ getParameterType(int param)134 int getParameterType(int param) throws SQLException; 135 136 /** 137 * Retrieves the designated parameter's database-specific type name. 138 * 139 * @param param the first parameter is 1, the second is 2, ... 140 * @return type the name used by the database. If the parameter type is 141 * a user-defined type, then a fully-qualified type name is returned. 142 * @exception SQLException if a database access error occurs 143 * @since 1.4 144 */ getParameterTypeName(int param)145 String getParameterTypeName(int param) throws SQLException; 146 147 148 /** 149 * Retrieves the fully-qualified name of the Java class whose instances 150 * should be passed to the method <code>PreparedStatement.setObject</code>. 151 * 152 * @param param the first parameter is 1, the second is 2, ... 153 * @return the fully-qualified name of the class in the Java programming 154 * language that would be used by the method 155 * <code>PreparedStatement.setObject</code> to set the value 156 * in the specified parameter. This is the class name used 157 * for custom mapping. 158 * @exception SQLException if a database access error occurs 159 * @since 1.4 160 */ getParameterClassName(int param)161 String getParameterClassName(int param) throws SQLException; 162 163 /** 164 * The constant indicating that the mode of the parameter is unknown. 165 */ 166 int parameterModeUnknown = 0; 167 168 /** 169 * The constant indicating that the parameter's mode is IN. 170 */ 171 int parameterModeIn = 1; 172 173 /** 174 * The constant indicating that the parameter's mode is INOUT. 175 */ 176 int parameterModeInOut = 2; 177 178 /** 179 * The constant indicating that the parameter's mode is OUT. 180 */ 181 int parameterModeOut = 4; 182 183 /** 184 * Retrieves the designated parameter's mode. 185 * 186 * @param param the first parameter is 1, the second is 2, ... 187 * @return mode of the parameter; one of 188 * <code>ParameterMetaData.parameterModeIn</code>, 189 * <code>ParameterMetaData.parameterModeOut</code>, or 190 * <code>ParameterMetaData.parameterModeInOut</code> 191 * <code>ParameterMetaData.parameterModeUnknown</code>. 192 * @exception SQLException if a database access error occurs 193 * @since 1.4 194 */ getParameterMode(int param)195 int getParameterMode(int param) throws SQLException; 196 } 197