单个字符插入的唯一约束违规

Question

我对SQL Server 2008数据库表有一个唯一约束，约束包含4列。在输入一些测试数据时，我意外地收到了一个唯一的约束违规。对于四列，我只输入一个数字，插入值集，递增数字，然后重复（即（1,1,1,1）（2,2,2,2，）......等） 。当我到达10时发生违规。如果我现在输入任何数字，它将违反约束。然后我尝试输入字母'A'，并试图插入以'A'开头的任何单词，这导致违规。我是否需要在约束中更改某些内容，或者它们实际上应该如何工作？

ALTER TABLE [dbo].[Table] ADD  CONSTRAINT [UC_Table_Column1_Column2_Column3_Column4] 
UNIQUE NONCLUSTERED 
(
    [Column1] ASC,
    [Column2] ASC,
    [Column3] ASC,
    [Column4] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF,    
IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON   
[PRIMARY]

Answer 1

这应该工作得很好。什么是实际的表定义？你的整理是什么？

-- Working Example
CREATE TABLE dbo.[Table](
      Column1 VARCHAR(50)
    , Column2 VARCHAR(50)
    , Column3 INT
    , Column4 VARCHAR(25)
);

ALTER TABLE [dbo].[Table] ADD  CONSTRAINT [UC_Table_Column1_Column2_Column3_Column4] 
UNIQUE NONCLUSTERED 
(
    [Column1] ASC,
    [Column2] ASC,
    [Column3] ASC,
    [Column4] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF,    
IGNORE_DUP_KEY = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON   
[PRIMARY]

DECLARE @iteration INT = 0;

WHILE @iteration < 20
BEGIN
    INSERT INTO [dbo].[Table]
    SELECT @iteration, @iteration, @iteration, @iteration;

    SET @iteration += 1;
END;

SELECT * FROM [dbo].[Table];