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
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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
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24 */
25
26package 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
43public 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}
197