Parameters

Learn IN and OUT parameters.

Procedures take IN, OUT and INOUT parameters.

CREATE PROCEDURE get_count(OUT cnt INT)
LANGUAGE SQL
AS $$
  SELECT COUNT(*) INTO cnt FROM products;
$$;

This query returns the count outward.

The procedure get_count is created. COUNT(*) INTO cnt is selected from products.

Parameters — details

IN takes from outside, OUT gives outward, INOUT does both.

For example, get_count(OUT cnt INT) writes the total row count into cnt; the caller reads this value as the result.

Create a get_count(OUT cnt INT) procedure.

Show example solution

CREATE PROCEDURE get_count(OUT cnt INT)
LANGUAGE SQL
AS $$
  SELECT COUNT(*) INTO cnt FROM products;
$$;

Add OUT

CREATE PROCEDURE get_count(____ cnt INT)

Show answer

CREATE PROCEDURE get_count(OUT cnt INT)

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