Not Exists的使用方法

當要存數據到oracle數據庫中時，要確認某一條數據的某個屬性在數據庫中是否已經存在，不存在則插去，存在則不插入

INSERT INTO PPORDER (
    ASNCREATEKEY,
    BOXCODE,
    SKUCODE,
    FACTORYID,
    DELIVERID,
    TEAMNO,
    ASN,
    PRODTIME,
    ASNLINE,
    STAUTS
) SELECT
    '123' AS ASNCREATEKEY,
    '123' AS BOXCODE,
    '123' AS SKUCODE,
    '123' AS FACTORYID,
    '123' AS DELIVERID,
    '123' AS TEAMNO,
    '123' AS ASN,
    TO_DATE ('1988-5-18', 'yyyy-mm-dd') AS PRODTIME,
    '123' AS ASNLINE,
    '0' AS STAUTS
FROM
    dual
WHERE
    NOT EXISTS (
        SELECT
            *
        FROM
            PPORDER
        WHERE
            ASNCREATEKEY = '123'
    );

注意：
要添加的字段後面記得要添加AS + 屬性 不然插入數據時，如果數據庫中數據存在則不插入，如果不存在則數據庫中有多少條數據就插入多少條要插入的數據，如果數據很多刪除很麻煩的。