Oracle – PL/SQL to check constraint exists before dropping

DECLARE numberOfRows INTEGER;
BEGIN

numberOfRows := 0;

SELECT

COUNT(*) INTO numberOfRows

FROM

all_constraints

WHERE

CONSTRAINT_NAME = 'Some_Constraint_Name_Goes_Here'
AND table_name = 'Some_Table_X'
AND OWNER = 'SA';

IF numberOfRows > 0 THEN

EXECUTE IMMEDIATE 'ALTER TABLE SA.Some_Table_X

Drop constraint Some_Constraint_Name_Goes_Here';

END IF;

END;