plpgsql_check: PL/pgSQL Linter

plpgsql_check is a Postgres extension that lints plpgsql for syntax, semantic and other related issues. The tool helps developers to identify and correct errors before executing the code. plpgsql_check is most useful for developers who are working with large or complex SQL codebases, as it can help identify and resolve issues early in the development cycle.

Enable the extension

-- Enable the "plpgsql_check" extension
create extension plpgsql_check;

-- Disable the "plpgsql_check" extension
drop extension if exists plpgsql_check;

API

• plpgsql_check_function( ... ): Scans a function for errors.

plpgsql_check_function is highly customizable. For a complete list of available arguments see the docs

Usage

To demonstrate plpgsql_check we can create a function with a known error. In this case we create a function some_func, that references a non-existent column place.created_at.

create table place(
  x float,
  y float
);

create or replace function public.some_func()
  returns void
  language plpgsql
as $$
declare
  rec record;
begin
  for rec in select * from place
  loop
    -- Bug: There is no column `created_at` on table `place`
    raise notice '%', rec.created_at;
  end loop;
end;
$$;

Note that executing the function would not catch the invalid reference error because the loop does not execute if no rows are present in the table.

select public.some_func();
  some_func
 ───────────

 (1 row)

Now we can use plpgsql_check's plpgsql_check_function function to identify the known error.

select plpgsql_check_function('public.some_func()');

                   plpgsql_check_function
------------------------------------------------------------
 error:42703:8:RAISE:record "rec" has no field "created_at"
 Context: SQL expression "rec.created_at"

Resources

• Official plpgsql_check documentation