Question

我尝试创建一个允许我在shipment_value表中添加新记录的程序，但我不想添加任何已存在的记录。所以我使用了WHERE NOT EXISTS条件，但我收到了一些编译错误。

CREATE OR REPLACE PROCEDURE Add_Shipment_Method(
shipment_method_id_p IN NUMBER,
shipment_description_p IN VARCHAR2)
AS
BEGIN
INSERT INTO shipment_method VALUES(shipment_method_id_p, shipment_description_p)
WHERE NOT EXISTS (SELECT * FROM SHIPMENT_METHOD WHERE SHIPMENT_METHOD_ID = shipment_method_id_p AND SHIPMENT_DESCRIPTION = shipment_description_p);
COMMIT;
END;

我的程序在添加＆＃34; NOT EXISTS＆＃34;之前运行良好，但现在我有编译错误

Answer 1

要使用不存在，您必须插入查询结果，而不是值列表。

如果您的数据库是oracle，您可以像这样使用

来插入插件

INSERT INTO shipment_method 
    SELECT shipment_method_id_p, shipment_description_p
    FROM dual
    WHERE NOT EXISTS (SELECT * FROM SHIPMENT_METHOD WHERE SHIPMENT_METHOD_ID = shipment_method_id_p AND SHIPMENT_DESCRIPTION = shipment_description_p);

或者如果您有唯一索引，则可以捕获异常。

带有NOT EXISTS编译错误的PL / SQL过程

1 个答案: