Question

鉴于以下T-SQL语句，我如何（通过检查）确定主键？如果没有列出（就像我怀疑的那样）它会是什么样子？

CREATE TABLE [dbo].[BLDGINFO](
    [LBLDGRUNNO] [int] NULL,
    [LBLDGNO] [int] NOT NULL,
    [FBIVOLUME] [float] NULL,
    [FBIACOND] [float] NULL,
    [NBIHTYPE] [float] NULL,
    [NBILTYPE] [float] NULL,
    [NBISTORIES] [float] NULL,
    [NBIFTYPE] [float] NULL,
    [NBIBEDS] [float] NULL,
    [NBIUNITS] [float] NULL,
    [SBIRATENO] [nvarchar](31) NULL,
    [NBICTYPE] [float] NULL,
    [NBIYEARBLT] [int] NULL DEFAULT ((0)),
    [NBITHBNDRY] [int] NULL
) ON [PRIMARY]

Answer 1

表中唯一可能作为主键使用的字段是LBLDGNO，因为主键列不能为空。

Answer 2

您问题中的表定义不包含主键，以下是将主键定义为id列的示例：

CREATE TABLE [dbo].[BLDGINFO](
    id int NOT NULL,
    [LBLDGRUNNO] [int] NULL,
    [LBLDGNO] [int] NOT NULL,
    [FBIVOLUME] [float] NULL,
    [FBIACOND] [float] NULL,
    [NBIHTYPE] [float] NULL,
    [NBILTYPE] [float] NULL,
    [NBISTORIES] [float] NULL,
    [NBIFTYPE] [float] NULL,
    [NBIBEDS] [float] NULL,
    [NBIUNITS] [float] NULL,
    [SBIRATENO] [nvarchar](31) NULL,
    [NBICTYPE] [float] NULL,
    [NBIYEARBLT] [int] NULL DEFAULT ((0)),
    [NBITHBNDRY] [int] NULL,
    PRIMARY KEY (id)
) ON [PRIMARY]

Answer 3

如果已经定义了主键，则它将是LBLDGNO。但是，很可能根本没有定义主键。您可以按如下方式确定：

SELECT c.name
FROM sys.indexes i, sys.index_columns ic, sys.objects o, sys.columns c
WHERE o.object_id = i.object_id
AND ic.index_id = i.index_id AND ic.object_id = i.object_id
AND c.object_id = o.object_id AND c.column_id = ic.column_id
AND i.is_primary_key = 1
AND o.name = 'BLDGINFO'

此查询将返回主键中包含的所有列。如果它返回一个空的结果集，则没有定义主键。

从SQL Server语句确定主键

3 个答案: