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3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5    * This code is free software; you can redistribute it and/or modify it
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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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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 }