PL/pgSQL syntax error

Question

I have a very simple PL/pgSQL script:

     declare x varchar(100);

When I run it I get a message:

    [WARNING  ] declare x varchar(100)
        ERROR:  syntax error at or near "varchar"
        LINE 1: declare x varchar(100)
                          ^

I really don't understand what is wrong with this.

Answer 1

you can use procedural statements only inside function body in PostgreSQL.

CREATE OR REPLACE FUNCTION foo()
RETURNS int AS 
$$ -- here start procedural part
   DECLARE x int;
   BEGIN
     x := 10;
     RETURN x;
   END;
$$ -- here finish procedural part
LANGUAGE plpgsql; -- language specification 

or in temporary function (anonymous block)

DO $$
DECLARE x int;
BEGIN
  x := 10;
  RAISE NOTICE '>>>%<<<', x;
END;
$$;

isn't possible to use procedural statements as SQL statements like T-SQL.