CallableStatement interface

• The interface used to execute SQL stored procedures.
• The JDBC API provides a stored procedure SQL escape syntax that allows stored procedures to be called in a standard way for all RDBMSs.
• This escape syntax has one form that includes a result parameter

{?= call <procedure-name>[(<arg1>,<arg2>, ...)]}

• If used, the result parameter must be registered as an OUT parameter.
• The other for that does not include a result parameter

{call <procedure-name>[(<arg1>,<arg2>, ...)]}

• The other parameters can be used for input, output or both. Parameters are referred to sequentially, by number, with the first parameter being 1.
• IN parameter values are set using the set methods inherited from PreparedStatement.
• The type of all OUT parameters must be registered prior to executing the stored procedure; their values are retrieved after execution via the get methods provided in CallableStatement.
• A CallableStatement can return one ResultSet object or multiple ResultSet objects.
• Multiple ResultSet objects are handled using operations inherited from Statement.
• For maximum portability, a call's ResultSet objects and update counts should be processed prior to getting the values of output parameters

Commonly used methods of CallableStatement interface

Modifier and Type	Method and Description
int	getInt(int parameterIndex) Retrieves the value of the designated JDBC INTEGER parameter as an int in the Java programming language.
int	getInt(String parameterName) Retrieves the value of a JDBC INTEGER parameter as an int in the Java programming language.
String	getString(int parameterIndex) Retrieves the value of the designated JDBC CHAR, VARCHAR, or LONGVARCHAR parameter as a String in the Java programming language.
String	getString(String parameterName) Retrieves the value of a JDBC CHAR, VARCHAR, or LONGVARCHAR parameter as a String in the Java programming language.