( [resource connection] )
db2_conn_error() returns an SQLSTATE value representing
the reason the last attempt to connect to a database failed. As
db2_connect() returns FALSE in the event of a failed
connection attempt, you do not pass any parameters to
db2_conn_error() to retrieve the SQLSTATE value.
If, however, the connection was successful but becomes invalid over time,
you can pass the connection parameter to retrieve
the SQLSTATE value for a specific connection.
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_conn_errormsg() to retrieve an
explicit error message and the associated SQLCODE value.