Invalid for loop in a function - postgresql

Question

I am trying to make the following function working:
CREATE OR REPLACE FUNCTION validate_count(devices TEXT[], campaign_id INTEGER) RETURNS void AS $$
DECLARE
devices_array TEXT[] := devices;
devices_count INTEGER := array_length(devices, 1);
row_id INTEGER := campaign_id;
BEGIN
FOR device IN unnest(devices_array) LOOP
IF my_count('my_table', device, row_id) != 1;
RAISE EXCEPTION 'invalid_count %', row_id
ENDIF
END LOOP;
END
$$ LANGUAGE plpgsql;
my_count is a working function which returns INTEGER.
The definition fails with the error:
ERROR: syntax error at or near "unnest"
LINE 7: FOR device IN unnest(devices_array) LOOP
Could you spot the issue? Thanks!
I am planning to call the function as follows:
select validate_count('{foo, bar}', 1)

Answer 1

Use a FOREACH loop:
CREATE OR REPLACE FUNCTION validate_count(devices TEXT[], campaign_id INTEGER)
RETURNS void
AS
$$
DECLARE
device text;
devices_count INTEGER := array_length(devices, 1);
BEGIN
FOREACH device IN ARRAY devices LOOP
IF my_count('my_table', device, campaign_id) <> 1 then
RAISE EXCEPTION 'invalid_count %', campaign_id;
END IF;
END LOOP;
END
$$
LANGUAGE plpgsql;

Answer 2

A few things need to be fixed to make this valid.
The FOR loop needs SELECT before the unnest, i.e.:
FOR device IN SELECT unnest(devices_array) LOOP
You need to declare device up top, for example:
DECLARE device RECORD;
The IF statement needs a THEN instead of a ;, i.e.:
IF my_count('my_table', device, row_id) != 1 THEN
The RAISE EXCEPTION statement needs a semicolon at the end of the line, i.e.:
RAISE EXCEPTION 'invalid_count %', row_id;
The END for the IF statement should be END IF;.
The END for the LOOP statement should be END LOOP;.
Here's the net result:
CREATE OR REPLACE FUNCTION validate_count(devices TEXT[], campaign_id INTEGER) RETURNS void AS $$
DECLARE
devices_array TEXT[] := devices;
devices_count INTEGER := array_length(devices, 1);
row_id INTEGER := campaign_id;
device RECORD;
BEGIN
FOR device IN SELECT unnest(devices_array) LOOP
IF my_count('my_table', device, row_id) != 1 THEN
RAISE EXCEPTION 'invalid_count %', row_id;
END IF;
END LOOP;
END
$$ LANGUAGE plpgsql;