Assert is usually implemented as custom functions and used via PERFORM statement now
-- usual current solution
PERFORM Assert(some expression)
I would to implement Assert as plpgsql internal statement due bigger possibilities to design syntax and internal implementation now and in future. More - as plpgsql statement should be compatible with any current code - because there should not be collision between SQL and PLpgSQL space. So this design doesn't break any current code.
I propose following syntax with following ecosystem:
ASSERT [ NOTICE, WARNING, >>EXCEPTION<< ]
[ string expression or literal - explicit message ]
[ USING clause - same as RAISE stmt (possible in future ) ]
( ROW_COUNT ( = | <> ) ( 1 | 0 ) |
( QUERY some query should not be empty ) |
( CHECK some expression should be true )
( IS NOT NULL expression should not be null )
Every variant (ROW_COUNT, QUERY, CHECK, IS NOT NULL) has own default message
These asserts can be controlled by set of options (by default asserts are enabled):
