Retrieves the first warning reported by calls on this Statement object. Subsequent Statement object warnings will be chained to this SQLWarning object.

The warning chain is automatically cleared each time a statement is (re)executed. This method may not be called on a closed Statement object; doing so will cause an SQLException to be thrown.

Note: If you are processing a ResultSet object, any warnings associated with reads on that ResultSet object will be chained on it rather than on the Statement object that produced it.

Returns:  the first SQLWarning object or null if there are no warnings

Exceptions:

SQLException

if a database access error occurs or this method is called on a closed Statement