( [resource connection] )
db2_conn_errormsg() returns an error message and SQLCODE
value representing the reason the last database connection attempt failed.
As db2_connect() returns FALSE in the event of a failed
connection attempt, do not pass any parameters to
db2_conn_errormsg() to retrieve the associated error
message and SQLCODE value.
If, however, the connection was successful but becomes invalid over time,
you can pass the connection parameter to retrieve
the associated error message and SQLCODE value for a specific connection.
Returns a string containing the error message and SQLCODE value resulting
from a failed connection attempt. If there is no error associated with the last
connection attempt, db2_conn_errormsg() returns an empty