PreparedStatement setNull(..)

Question

Java PreparedStatement provides a possibility to explicitely set a Null value. This possibility is:

prepStmt.setNull(parameterIndex, Types.VARCHAR); 

Are the semantics of this call the same as when using a specific setType with a null parameter?

prepStmt.setString(null); 

?

Answer 1

but watch out for this....

Long nullLong = null;  preparedStatement.setLong( nullLong ); 

-thows null pointer exception-

because the protype is

setLong( long )    

NOT

setLong( Long ) 

nice one to catch you out eh.

Answer 2

This guide says:

6.1.5 Sending JDBC NULL as an IN parameter

The setNull method allows a programmer to send a JDBC NULL (a generic SQL NULL) value to the database as an IN parameter. Note, however, that one must still specify the JDBC type of the parameter.

A JDBC NULL will also be sent to the database when a Java null value is passed to a setXXX method (if it takes Java objects as arguments). The method setObject, however, can take a null value only if the JDBC type is specified.

So yes they're equivalent.