/*
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

/*
 * @(#)PreparedStatement.java	1.6 03/10/21
 */

package java.sql;

import java.util.Calendar;

/**
 * An object that represents a precompiled SQL statement.
 * <P>A SQL statement is precompiled and stored in a
 * <code>PreparedStatement</code> object. This object can then be used to
 * efficiently execute this statement multiple times. 
 *
 * <P><B>Note:</B> The setter methods (<code>setShort</code>, <code>setString</code>,
 * and so on) for setting IN parameter values
 * must specify types that are compatible with the defined SQL type of
 * the input parameter. For instance, if the IN parameter has SQL type
 * <code>INTEGER</code>, then the method <code>setInt</code> should be used.
 *
 * <p>If arbitrary parameter type conversions are required, the method
 * <code>setObject</code> should be used with a target SQL type.
 * <P>
 * In the following example of setting a parameter, <code>con</code> represents
 * an active connection:  
 * <PRE>
 *   PreparedStatement pstmt = con.prepareStatement("UPDATE EMPLOYEES
 *                                     SET SALARY = ? WHERE ID = ?");
 *   pstmt.setFloat(1, 153833.89)
 *   pstmt.setInt(2, 110592)
 * </PRE>
 *
 * @see Connection#prepareStatement
 * @see ResultSet 
 */

public interface PreparedStatement extends Statement {

    /**
     * Executes the SQL query in this <code>PreparedStatement</code> object
     * and returns the <code>ResultSet</code> object generated by the query.
     *
     * @return a <code>ResultSet</code> object that contains the data produced by the
     *         query; never <code>null</code>
     * @exception SQLException if a database access error occurs or the SQL
     *            statement does not return a <code>ResultSet</code> object
     */
    ResultSet executeQuery() throws SQLException;

    /**
     * Executes the SQL statement in this <code>PreparedStatement</code> object,
     * which must be an SQL <code>INSERT</code>, <code>UPDATE</code> or
     * <code>DELETE</code> statement; or an SQL statement that returns nothing, 
     * such as a DDL statement.
     *
     * @return either (1) the row count for <code>INSERT</code>, <code>UPDATE</code>,
     *         or <code>DELETE</code> statements
     *         or (2) 0 for SQL statements that return nothing
     * @exception SQLException if a database access error occurs or the SQL
     *            statement returns a <code>ResultSet</code> object
     */
    int executeUpdate() throws SQLException;

    /**
     * Sets the designated parameter to SQL <code>NULL</code>.
     *
     * <P><B>Note:</B> You must specify the parameter's SQL type.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param sqlType the SQL type code defined in <code>java.sql.Types</code>
     * @exception SQLException if a database access error occurs
     */
    void setNull(int parameterIndex, int sqlType) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>boolean</code> value.
     * The driver converts this
     * to an SQL <code>BIT</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setBoolean(int parameterIndex, boolean x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>byte</code> value.  
     * The driver converts this
     * to an SQL <code>TINYINT</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setByte(int parameterIndex, byte x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>short</code> value. 
     * The driver converts this
     * to an SQL <code>SMALLINT</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setShort(int parameterIndex, short x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>int</code> value.  
     * The driver converts this
     * to an SQL <code>INTEGER</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setInt(int parameterIndex, int x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>long</code> value. 
     * The driver converts this
     * to an SQL <code>BIGINT</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setLong(int parameterIndex, long x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>float</code> value. 
     * The driver converts this
     * to an SQL <code>FLOAT</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setFloat(int parameterIndex, float x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>double</code> value.  
     * The driver converts this
     * to an SQL <code>DOUBLE</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setDouble(int parameterIndex, double x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java <code>String</code> value. 
     * The driver converts this
     * to an SQL <code>VARCHAR</code> or <code>LONGVARCHAR</code> value
     * (depending on the argument's
     * size relative to the driver's limits on <code>VARCHAR</code> values)
     * when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setString(int parameterIndex, String x) throws SQLException;

    /**
     * Sets the designated parameter to the given Java array of bytes.  The driver converts
     * this to an SQL <code>VARBINARY</code> or <code>LONGVARBINARY</code>
     * (depending on the argument's size relative to the driver's limits on
     * <code>VARBINARY</code> values) when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value 
     * @exception SQLException if a database access error occurs
     */
    void setBytes(int parameterIndex, byte x[]) throws SQLException;

    /**
     * Sets the designated parameter to the given <code>java.sql.Date</code> value.  
     * The driver converts this
     * to an SQL <code>DATE</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setDate(int parameterIndex, java.sql.Date x)
	    throws SQLException;

    /**
     * Sets the designated parameter to the given <code>java.sql.Time</code> value.  
     * The driver converts this
     * to an SQL <code>TIME</code> value when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    void setTime(int parameterIndex, java.sql.Time x) 
	    throws SQLException;

    /**
     * Sets the designated parameter to the given <code>java.sql.Timestamp</code> value.  
     * The driver
     * converts this to an SQL <code>TIMESTAMP</code> value when it sends it to the
     * database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value 
     * @exception SQLException if a database access error occurs
     */
    void setTimestamp(int parameterIndex, java.sql.Timestamp x)
	    throws SQLException;

    /**
     * Sets the designated parameter to the given input stream, which will have 
     * the specified number of bytes.
     * When a very large ASCII value is input to a <code>LONGVARCHAR</code>
     * parameter, it may be more practical to send it via a
     * <code>java.io.InputStream</code>. Data will be read from the stream
     * as needed until end-of-file is reached.  The JDBC driver will
     * do any necessary conversion from ASCII to the database char format.
     * 
     * <P><B>Note:</B> This stream object can either be a standard
     * Java stream object or your own subclass that implements the
     * standard interface.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the Java input stream that contains the ASCII parameter value
     * @param length the number of bytes in the stream 
     * @exception SQLException if a database access error occurs
     */
    void setAsciiStream(int parameterIndex, java.io.InputStream x, int length)
	    throws SQLException;

    /**
     * Sets the designated parameter to the given input stream, which will have 
     * the specified number of bytes.
     * When a very large binary value is input to a <code>LONGVARBINARY</code>
     * parameter, it may be more practical to send it via a
     * <code>java.io.InputStream</code> object. The data will be read from the 
     * stream as needed until end-of-file is reached.
     * 
     * <P><B>Note:</B> This stream object can either be a standard
     * Java stream object or your own subclass that implements the
     * standard interface.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the java input stream which contains the binary parameter value
     * @param length the number of bytes in the stream 
     * @exception SQLException if a database access error occurs
     */
    void setBinaryStream(int parameterIndex, java.io.InputStream x, 
			 int length) throws SQLException;

    /**
     * Clears the current parameter values immediately.
     * <P>In general, parameter values remain in force for repeated use of a
     * statement. Setting a parameter value automatically clears its
     * previous value.  However, in some cases it is useful to immediately
     * release the resources used by the current parameter values; this can
     * be done by calling the method <code>clearParameters</code>.
     *
     * @exception SQLException if a database access error occurs
     */
    void clearParameters() throws SQLException;

    //----------------------------------------------------------------------
    // Advanced features:

    /**
     * <p>Sets the value of the designated parameter with the given object. The second
     * argument must be an object type; for integral values, the
     * <code>java.lang</code> equivalent objects should be used.
     *
     * <p>The given Java object will be converted to the given targetSqlType
     * before being sent to the database.
     *
     * If the object has a custom mapping (is of a class implementing the 
     * interface <code>SQLData</code>),
     * the JDBC driver should call the method <code>SQLData.writeSQL</code> to 
     * write it to the SQL data stream.
     * If, on the other hand, the object is of a class implementing
     * <code>Blob</code> or <code>Clob</code>
     * , the driver should pass it to the database as a 
     * value of the corresponding SQL type.
     *
     * <p>Note that this method may be used to pass database-specific
     * abstract data types. 
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the object containing the input parameter value
     * @param targetSqlType the SQL type (as defined in java.sql.Types) to be 
     * sent to the database. The scale argument may further qualify this type.
     * @param scale for java.sql.Types.DECIMAL or java.sql.Types.NUMERIC types,
     *          this is the number of digits after the decimal point.  For all other
     *          types, this value will be ignored.
     * @exception SQLException if a database access error occurs
     * @see Types 
     */
    void setObject(int parameterIndex, Object x, int targetSqlType, int scale)
            throws SQLException;

   /**
    * Sets the value of the designated parameter with the given object.
    * This method is like the method <code>setObject</code>
    * above, except that it assumes a scale of zero.
    *
    * @param parameterIndex the first parameter is 1, the second is 2, ...
    * @param x the object containing the input parameter value
    * @param targetSqlType the SQL type (as defined in java.sql.Types) to be 
    *                      sent to the database
    * @exception SQLException if a database access error occurs
    */
    void setObject(int parameterIndex, Object x, int targetSqlType) 
      throws SQLException;

    /**
     * <p>Sets the value of the designated parameter using the given object. 
     * The second parameter must be of type <code>Object</code>; therefore, the
     * <code>java.lang</code> equivalent objects should be used for built-in types.
     *
     * <p>The JDBC specification specifies a standard mapping from
     * Java <code>Object</code> types to SQL types.  The given argument 
     * will be converted to the corresponding SQL type before being
     * sent to the database.
     *
     * <p>Note that this method may be used to pass datatabase-
     * specific abstract data types, by using a driver-specific Java
     * type.
     *
     * If the object is of a class implementing the interface <code>SQLData</code>,
     * the JDBC driver should call the method <code>SQLData.writeSQL</code>
     * to write it to the SQL data stream.
     * If, on the other hand, the object is of a class implementing
     * <code>Blob</code> or <code>Clob</code>, 
     * the driver should pass it to the database as a 
     * value of the corresponding SQL type.
     * <P>
     * This method throws an exception if there is an ambiguity, for example, if the
     * object is of a class implementing more than one of the interfaces named above.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the object containing the input parameter value 
     * @exception SQLException if a database access error occurs or the type 
     *            of the given object is ambiguous
     */
    void setObject(int parameterIndex, Object x) throws SQLException;

    /**
     * Executes the SQL statement in this <code>PreparedStatement</code> object,
     * which may be any kind of SQL statement.
     * Some prepared statements return multiple results; the <code>execute</code>
     * method handles these complex statements as well as the simpler
     * form of statements handled by the methods <code>executeQuery</code>
     * and <code>executeUpdate</code>.
     * <P>
     * The <code>execute</code> method returns a <code>boolean</code> to
     * indicate the form of the first result.  You must call either the method
     * <code>getResultSet</code> or <code>getUpdateCount</code>
     * to retrieve the result; you must call <code>getMoreResults</code> to
     * move to any subsequent result(s).
     *
     * @return <code>true</code> if the first result is a <code>ResultSet</code>
     *         object; <code>false</code> if the first result is an update
     *         count or there is no result
     * @exception SQLException if a database access error occurs or an argument
     *            is supplied to this method
     * @see Statement#execute
     * @see Statement#getResultSet
     * @see Statement#getUpdateCount
     * @see Statement#getMoreResults

     */
    boolean execute() throws SQLException;

    //--------------------------JDBC 2.0-----------------------------

    /**
     * Adds a set of parameters to this <code>PreparedStatement</code>
     * object's batch of commands.
     * 
     * @exception SQLException if a database access error occurs
     * @see Statement#addBatch
     * @since 1.2
     */
    void addBatch() throws SQLException;

    /**
     * Sets the designated parameter to the given <code>Reader</code>
     * object, which is the given number of characters long.
     * When a very large UNICODE value is input to a <code>LONGVARCHAR</code>
     * parameter, it may be more practical to send it via a
     * <code>java.io.Reader</code> object. The data will be read from the stream
     * as needed until end-of-file is reached.  The JDBC driver will
     * do any necessary conversion from UNICODE to the database char format.
     * 
     * <P><B>Note:</B> This stream object can either be a standard
     * Java stream object or your own subclass that implements the
     * standard interface.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param reader the <code>java.io.Reader</code> object that contains the 
     *        Unicode data
     * @param length the number of characters in the stream 
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    void setCharacterStream(int parameterIndex,
       			  java.io.Reader reader,
			  int length) throws SQLException;

    /**
     * Sets the designated parameter to the given <code>Blob</code> object.
     * The driver converts this to an SQL <code>BLOB</code> value when it
     * sends it to the database.
     *
     * @param i the first parameter is 1, the second is 2, ...
     * @param x a <code>Blob</code> object that maps an SQL <code>BLOB</code> value
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    void setBlob (int i, Blob x) throws SQLException;

    /**
     * Sets the designated parameter to the given <code>Clob</code> object.
     * The driver converts this to an SQL <code>CLOB</code> value when it
     * sends it to the database.
     *
     * @param i the first parameter is 1, the second is 2, ...
     * @param x a <code>Clob</code> object that maps an SQL <code>CLOB</code> value
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    void setClob (int i, Clob x) throws SQLException;

    /**
     * Retrieves a <code>ResultSetMetaData</code> object that contains
     * information about the columns of the <code>ResultSet</code> object
     * that will be returned when this <code>PreparedStatement</code> object 
     * is executed.
     * <P>
     * Because a <code>PreparedStatement</code> object is precompiled, it is
     * possible to know about the <code>ResultSet</code> object that it will
     * return without having to execute it.  Consequently, it is possible
     * to invoke the method <code>getMetaData</code> on a
     * <code>PreparedStatement</code> object rather than waiting to execute
     * it and then invoking the <code>ResultSet.getMetaData</code> method
     * on the <code>ResultSet</code> object that is returned.
     * <P>
     * <B>NOTE:</B> Using this method may be expensive for some drivers due
     * to the lack of underlying DBMS support.
     *
     * @return the description of a <code>ResultSet</code> object's columns or
     *         <code>null</code> if the driver cannot return a
     *         <code>ResultSetMetaData</code> object
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    ResultSetMetaData getMetaData() throws SQLException;

    /**
     * Sets the designated parameter to the given <code>java.sql.Date</code> value,
     * using the given <code>Calendar</code> object.  The driver uses
     * the <code>Calendar</code> object to construct an SQL <code>DATE</code> value,
     * which the driver then sends to the database.  With a
     * a <code>Calendar</code> object, the driver can calculate the date
     * taking into account a custom timezone.  If no
     * <code>Calendar</code> object is specified, the driver uses the default
     * timezone, which is that of the virtual machine running the application.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @param cal the <code>Calendar</code> object the driver will use
     *            to construct the date
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    void setDate(int parameterIndex, java.sql.Date x, Calendar cal)
	    throws SQLException;

    /**
     * Sets the designated parameter to the given <code>java.sql.Time</code> value,
     * using the given <code>Calendar</code> object.  The driver uses
     * the <code>Calendar</code> object to construct an SQL <code>TIME</code> value,
     * which the driver then sends to the database.  With a
     * a <code>Calendar</code> object, the driver can calculate the time
     * taking into account a custom timezone.  If no
     * <code>Calendar</code> object is specified, the driver uses the default
     * timezone, which is that of the virtual machine running the application.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @param cal the <code>Calendar</code> object the driver will use
     *            to construct the time
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    void setTime(int parameterIndex, java.sql.Time x, Calendar cal) 
	    throws SQLException;

    /**
     * Sets the designated parameter to the given <code>java.sql.Timestamp</code> value,
     * using the given <code>Calendar</code> object.  The driver uses
     * the <code>Calendar</code> object to construct an SQL <code>TIMESTAMP</code> value,
     * which the driver then sends to the database.  With a
     *  <code>Calendar</code> object, the driver can calculate the timestamp
     * taking into account a custom timezone.  If no
     * <code>Calendar</code> object is specified, the driver uses the default
     * timezone, which is that of the virtual machine running the application.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value 
     * @param cal the <code>Calendar</code> object the driver will use
     *            to construct the timestamp
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    void setTimestamp(int parameterIndex, java.sql.Timestamp x, Calendar cal)
	    throws SQLException;

    /**
     * Sets the designated parameter to SQL <code>NULL</code>.
     * This version of the method <code>setNull</code> should
     * be used for user-defined types.  Examples
     * of user-defined types include: DISTINCT, JAVA_OBJECT, and 
     * named array types.
     *
     * <P><B>Note:</B> To be portable, applications must give the
     * SQL type code and the fully-qualified SQL type name when specifying
     * a NULL user-defined.  In the case of a user-defined type 
     * the name is the type name of the parameter itself.  For a REF 
     * parameter, the name is the type name of the referenced type.  If 
     * a JDBC driver does not need the type code or type name information, 
     * it may ignore it.     
     *
     * Although it is intended for user-defined,
     * this method may be used to set a null parameter of any JDBC type.
     * If the parameter does not have a user-defined, the given
     * typeName is ignored
     *
     *
     * @param paramIndex the first parameter is 1, the second is 2, ...
     * @param sqlType a value from <code>java.sql.Types</code>
     * @param typeName the fully-qualified name of an SQL user-defined type;
     *  ignored if the parameter is not a user-defined type 
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
  void setNull (int paramIndex, int sqlType, String typeName) 
    throws SQLException;

    //------------------------- JDBC 3.0 -----------------------------------

    /**
     * Sets the designated parameter to the given <code>java.net.URL</code> value. 
     * The driver converts this to an SQL <code>DATALINK</code> value
     * when it sends it to the database.
     *
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the <code>java.net.URL</code> object to be set
     * @exception SQLException if a database access error occurs
     * @since 1.4
     */ 
    void setURL(int parameterIndex, java.net.URL x) throws SQLException;

}
