t-sql NOT IN有多列

Question

我有一个Microsoft SQL数据库,我试图插入一些数据.我在4列上有一个唯一的键,我想在检查数据时将多个表中的数据插入到该表中,以确保它不会违反键的唯一性.如果我在一个列上做这个,我会做一个NOT IN,就像这样.

INSERT TABLE_A (FLD_1)
    SELECT FLD_1
        FROM TBL_B
        INNER JOIN TBL_C
            ON TBL_B.FLD_1 = TBL_C.FLD_1
    WHERE TBL_B.FLD_1 NOT IN
        (
        SELECT TBL_A.FLD_1 FROM TBL_A
        )

有什么想法吗？

Answer 1

请使用NOT EXISTS,因为您必须处理多个列.

http://www.techonthenet.com/sql/exists.php

编辑:

未经测试,但大致是这样的:

SELECT FLD_1
FROM TBL_B
INNER JOIN TBL_C  ON TBL_B.FLD_1 = TBL_C.FLD_1
WHERE NOT EXISTS 
    (
    SELECT TBL_A.FLD_1 FROM TBL_A INNER JOIN TBL_B ON TBL_B.FLD1 = TBL_A.FLD1
    )

对于多列检查,大致如下:

SELECT FLD_1, FLD_2, FLD_3, FLD_4)
FROM TBL_B
INNER JOIN TBL_C  ON TBL_B.FLD_1 = TBL_C.FLD_1
WHERE NOT EXISTS 
    (
    SELECT TBL_A.FLD_1, TBL_A.FLD_2, TBL_A.FLD_3, TBL_A.FLD_4 
    FROM TBL_A 
    INNER JOIN TBL_B ON TBL_B.FLD1 = TBL_A.FLD1 AND 
                        TBL_B.FLD2 = TBL_A.FLD2 AND 
                        TBL_B.FLD3 = TBL_A.FLD3 AND 
                        TBL_B.FLD4 = TBL_A.FLD4 
    )