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 */
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 */
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 */
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 */
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 */
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 */
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 */
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 */
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 */
195 int getParameterMode(int param) throws SQLException;
196 }