附加唯一值 MS Access Query

Question

我有 2 个表，源表名为 “QA”，目标表名为 “Combine”。我只想根据 [Call_ID] 标准附加唯一记录。我需要 where 子句方面的帮助，插入查询是：

INSERT INTO combine ( source, date_update, [Year], [Month], [Day], quarter, week, QAcount, sup, agent_name, QA_A, date_c, login_name, QA_CALL_ID )
SELECT "QA" AS source, Date() AS CURDATE, Year([date_c]) AS Y, Month([date_c]) AS M, Day([date_c]) AS D, DatePart('q',[date_c]) AS Q, Weekday([date_c],1) AS W, "1" AS [count], Roster.Supervisor, Roster.agent_name, QA.QA_A, QA.date_c, QA.login_name, QA.[Call ID]
FROM QA LEFT JOIN Roster ON QA.login_name = Roster.tCAM;

仅在 [QA].[Call ID] 不同于 [combine].[QA_CALL_ID] 且不为空的情况下插入。请帮我看看这句话。

Answer 1

WHERE [QA].[Call ID] <> [combine].[QA_CALL_ID] AND [combine].[QA_CALL_ID] NOT IS NULL

可能缺少 Access 喜欢使用大量的括号。