Oracle中定義方法以及呼叫方法

-- 定義方法
CREATE OR REPLACE FUNCTION get_user_id(customer_name VARCHAR2)
    RETURN NUMBER
    IS
        cus_id NUMBER(4);
    BEGIN
        SELECT customerID INTO cus_id
        FROM userInfo
        WHERE customerName=customer_name;
    RETURN cus_id;
END;

-- 呼叫方法
VAR result NUMBER;
CALL
 
 get_user_id('') into :result;
PRINT result;

-- 也可以在查詢中直接呼叫方法
select * from userInfo where customerID=(get_user_id('username'));