Tuesday, March 20, 2012

Postgres script - for loop two dimension array using array upper and lower


A basic script to loop over an array in psql-


CREATE OR REPLACE FUNCTION func1(n character varying, v character varying)

  RETURNS integer AS

$BODY$

    DECLARE   

       return_code integer;

    BEGIN

       RAISE NOTICE '(%,%)', n, v;          

       return_code := 1;

    RETURN return_code; 

    EXCEPTION 

        WHEN NO_DATA_FOUND THEN           
           RETURN -1;
    END;

    $BODY$

  LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION func2()

  RETURNS integer AS

$BODY$

    DECLARE      

       return_code integer;

       pairs varchar[][] := array[['key2','val2'],

                            ['key1','val2']];

    BEGIN

        FOR i IN array_lower(pairs, 1) .. array_upper(pairs, 1)

        LOOP

         --RAISE NOTICE '%,%',pairs[i][1]::varchar, pairs[i][2]::varchar;

           PERFORM func1(pairs[i][1]::varchar, pairs[i][2]::varchar);

        END LOOP;

    return 1;

    END;

    $BODY$

  LANGUAGE plpgsql;

SELECT * from func2();

1 comment:

Harpreet Singh said...

from stackoverflow-

Since PostgreSQL 9.1 there is the very convenient (and fast) FOREACH you can:

DO
$BODY$
DECLARE
m varchar[];
arr varchar[][] := array[['key1','val1'],['key2','val2']];
BEGIN
FOREACH m SLICE 1 IN ARRAY arr
LOOP
RAISE NOTICE 'another_func(%,%)',m[1], m[2];
END LOOP;
END;
$BODY$ language plpgsql