cara menghindari kolom di klausa 'di mana' jika parameter 'TIDAK LULUS' postgresql

Tidak terlalu jelas apa yang Anda maksud dengan dilewati , tapi mungkin maksud Anda $3 adalah parameter opsional, dengan $3 absen artinya:tidak peduli ?

SELECT *
FROM employee
WHERE name = $1
AND age = $2
AND ( $3 IS NULL OR salary = $3)
   ;

Beberapa data:

CREATE TABLE employee
        ( name varchar NOT NULL PRIMARY KEY
        , age integer
        , salary integer
        );

INSERT INTO employee ( name , age , salary ) VALUES
 ( 'Alice' , 13 , 3 )
,( 'Bob' , 11 , 5 )
,( 'Charlotte' , 15 , 9 )
,( 'David' , 17 , 10 )
        ;

Sama seperti kueri yang disiapkan:

PREPARE qry (text, integer , integer) AS
SELECT *
FROM employee
WHERE name = $1
AND age = $2
AND ( $3 IS NULL OR salary = $3)
   ;

    -- and call the prepared statement:
EXECUTE qry ('Alice', 13, 3);
EXECUTE qry ('Alice', 13, NULL);

Keluaran:

CREATE TABLE
INSERT 0 4
PREPARE
 name  | age | salary 
-------+-----+--------
 Alice |  13 |      3
(1 row)

 name  | age | salary 
-------+-----+--------
 Alice |  13 |      3
(1 row)