-- -- Test error trapping -- create function trap_zero_divide(int) returns int as $$ declare x int; sx smallint; begin begin -- start a subtransaction raise notice 'should see this'; x := 100 / $1; raise notice 'should see this only if % <> 0', $1; sx := $1; raise notice 'should see this only if % fits in smallint', $1; if $1 < 0 then raise exception '% is less than zero', $1; end if; exception when division_by_zero then raise notice 'caught division_by_zero'; x := -1; when NUMERIC_VALUE_OUT_OF_RANGE then raise notice 'caught numeric_value_out_of_range'; x := -2; end; return x; end$$ language plpgsql; select trap_zero_divide(50); select trap_zero_divide(0); select trap_zero_divide(100000); select trap_zero_divide(-100); create table match_source as select x as id, x*10 as data, x/10 as ten from generate_series(1,100) x; create function trap_matching_test(int) returns int as $$ declare x int; sx smallint; y int; begin begin -- start a subtransaction x := 100 / $1; sx := $1; select into y data from match_source where id = (select id from match_source b where ten = $1); exception when data_exception then -- category match raise notice 'caught data_exception'; x := -1; when NUMERIC_VALUE_OUT_OF_RANGE OR CARDINALITY_VIOLATION then raise notice 'caught numeric_value_out_of_range or cardinality_violation'; x := -2; end; return x; end$$ language plpgsql; select trap_matching_test(50); select trap_matching_test(0); select trap_matching_test(100000); select trap_matching_test(1); create temp table foo (f1 int); create function subxact_rollback_semantics() returns int as $$ declare x int; begin x := 1; insert into foo values(x); begin x := x + 1; insert into foo values(x); raise exception 'inner'; exception when others then x := x * 10; end; insert into foo values(x); return x; end$$ language plpgsql; select subxact_rollback_semantics(); select * from foo; drop table foo; create function trap_timeout() returns void as $$ begin declare x int; begin -- we assume this will take longer than 1 second: select count(*) into x from generate_series(1, 1000000000000); exception when others then raise notice 'caught others?'; when query_canceled then raise notice 'nyeah nyeah, can''t stop me'; end; -- Abort transaction to abandon the statement_timeout setting. Otherwise, -- the next top-level statement would be vulnerable to the timeout. raise exception 'end of function'; end$$ language plpgsql; begin; set statement_timeout to 1000; select trap_timeout(); rollback; -- Test for pass-by-ref values being stored in proper context create function test_variable_storage() returns text as $$ declare x text; begin x := '1234'; begin x := x || '5678'; -- force error inside subtransaction SPI context perform trap_zero_divide(-100); exception when others then x := x || '9012'; end; return x; end$$ language plpgsql; select test_variable_storage(); -- -- test foreign key error trapping -- create temp table root(f1 int primary key); create temp table leaf(f1 int references root deferrable); insert into root values(1); insert into leaf values(1); insert into leaf values(2); -- fails create function trap_foreign_key(int) returns int as $$ begin begin -- start a subtransaction insert into leaf values($1); exception when foreign_key_violation then raise notice 'caught foreign_key_violation'; return 0; end; return 1; end$$ language plpgsql; create function trap_foreign_key_2() returns int as $$ begin begin -- start a subtransaction set constraints all immediate; exception when foreign_key_violation then raise notice 'caught foreign_key_violation'; return 0; end; return 1; end$$ language plpgsql; select trap_foreign_key(1); select trap_foreign_key(2); -- detects FK violation begin; set constraints all deferred; select trap_foreign_key(2); -- should not detect FK violation savepoint x; set constraints all immediate; -- fails rollback to x; select trap_foreign_key_2(); -- detects FK violation commit; -- still fails drop function trap_foreign_key(int); drop function trap_foreign_key_2();