Returns a string containing the SQLSTATE value returned by an SQL statement.
If you do not pass a statement resource as an argument to db2_stmt_error(), the driver returns the SQLSTATE value associated with the last attempt to return a statement resource, for example, from db2_prepare() or db2_exec().
To learn what the SQLSTATE value means, you can issue the following command
at a DB2 Command Line Processor prompt:
db2 '? sqlstate-value'. You
can also call db2_stmt_errormsg() to retrieve an
explicit error message and the associated SQLCODE value.