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java.sql
Interface SQLData

public interface SQLData

The interface used for the custom mapping of SQL user-defined types. This interface must be implemented by any Java class that is registered in a type mapping. It is expected that this interface will normally be implemented by a tool. The methods in this interface are called by the driver and are never called by a programmer directly.

Since:

1.2

See Also:

What Is in the JDBC 2.0 API

Method Summary

String	getSQLTypeName() Returns the fully-qualified name of the SQL user-defined type that this object represents.
void	readSQL(SQLInput stream, String typeName) Populates this object with data read from the database.
void	writeSQL(SQLOutput stream) Writes this object to the given SQL data stream, converting it back to its SQL value in the data source.

Method Detail

getSQLTypeName

public String getSQLTypeName()
                      throws SQLException

Returns the fully-qualified name of the SQL user-defined type that this object represents. This method is called by the JDBC driver to get the name of the UDT instance that is being mapped to this instance of SQLData.

Returns:

the type name that was passed to the method readSql when this object was constructed and populated

Throws:

SQLException - if there is a database access error

Since:

1.2

See Also:

What Is in the JDBC 2.0 API

readSQL

public void readSQL(SQLInput stream,
                    String typeName)
             throws SQLException

Populates this object with data read from the database. The implementation of the method must follow this protocol:

• It must read each of the attributes or elements of the SQL type from the given input stream. This is done by calling a method of the input stream to read each item, in the order that they appear in the SQL definition of the type.
• The method readSQL then assigns the data to appropriate fields or elements (of this or other objects). Specifically, it must call the appropriate SQLInput.readXXX method(s) to do the following: for a distinct type, read its single data element; for a structured type, read a value for each attribute of the SQL type.

The JDBC driver initializes the input stream with a type map before calling this method, which is used by the appropriate SQLInput.readXXX method on the stream.

Parameters:

stream - the SQLInput object from which to read the data for the value that is being custom mapped

typeName - the SQL type name of the value on the data stream

Throws:

SQLException - if there is a database access error

See Also:

SQLInput

writeSQL

public void writeSQL(SQLOutput stream)
              throws SQLException

Writes this object to the given SQL data stream, converting it back to its SQL value in the data source. The implementation of the method must follow this protocol:
It must write each of the attributes of the SQL type to the given output stream. This is done by calling a method of the output stream to write each item, in the order that they appear in the SQL definition of the type. Specifically, it must call the appropriate SQLOutput.writeXXX method(s) to do the following: for a Distinct Type, write its single data element; for a Structured Type, write a value for each attribute of the SQL type.

Parameters:

stream - the SQLOutput object to which to write the data for the value that was custom mapped

Throws:

SQLException - if there is a database access error

Since:

1.2

See Also:

SQLOutput, What Is in the JDBC 2.0 API