!3 create a user so that subsequent inserts would fail

!|execute procedure|createuser|
|new name|new username|
|arthur dent|adent|

#!3 check for any error

!|execute procedure expect exception|createuser|
|new name|new username|
|arthur dent|adent|

{{{
This doesn't work currently, because Postgres does not support the vendor-specific getErrorCode() API.
Instead of mapping to made-up error codes, a feature needs to be added to check against the SQL state.

#!3 check for a specific error code

!|execute procedure expect exception|createuser|2304|
|new name|new username|
|arthur dent|adent|
}}}