oracle编写自定义函数例子

CREATE OR REPLACE 
FUNCTION "GET_MON_BY_OFFSET" (y_value IN NUMBER, offset IN NUMBER)
RETURN VARCHAR2
Authid Current_User
AS
v_mon VARCHAR2(10);
BEGIN

v_mon := SUBSTR(0||TO_CHAR( y_value - offset),length(0 || TO_CHAR( y_value - offset))-1 ,2) ;
    -- routine body goes here, e.g.
    -- DBMS_OUTPUT.PUT_LINE('Navicat for Oracle');
    RETURN v_mon;
END;

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运行结果：