如何确定列是否在其表的主键中？(SQL Server)

Question

我目前正在使用......

select Table_Name, Column_name, data_type, is_Nullable
from information_Schema.Columns

...为了生成DataAccess Layer,确定给定数据库中列的信息.

从哪里可以检索有关这些列是否是其表的主键中的参与者的信息？

Answer 1

这是一种方法(将'keycol'替换为您要搜索的列名称):

SELECT  K.TABLE_NAME ,
    K.COLUMN_NAME ,
    K.CONSTRAINT_NAME
FROM    INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C
        JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K ON C.TABLE_NAME = K.TABLE_NAME
                                                         AND C.CONSTRAINT_CATALOG = K.CONSTRAINT_CATALOG
                                                         AND C.CONSTRAINT_SCHEMA = K.CONSTRAINT_SCHEMA
                                                         AND C.CONSTRAINT_NAME = K.CONSTRAINT_NAME
WHERE   C.CONSTRAINT_TYPE = 'PRIMARY KEY'
        AND K.COLUMN_NAME = 'keycol';

Answer 2

同样,以下内容将为您提供有关所有表及其键的信息,而不是有关特定列的信息.这样,您可以确保拥有所有感兴趣的列并知道它们参与的内容.为了查看所有键(主键,外键,唯一键),请注释WHERE子句.

SELECT K.TABLE_NAME, C.CONSTRAINT_TYPE, K.COLUMN_NAME, K.CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS C
JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS K
ON C.TABLE_NAME = K.TABLE_NAME
AND C.CONSTRAINT_CATALOG = K.CONSTRAINT_CATALOG
AND C.CONSTRAINT_SCHEMA = K.CONSTRAINT_SCHEMA
AND C.CONSTRAINT_NAME = K.CONSTRAINT_NAME
WHERE C.CONSTRAINT_TYPE = 'PRIMARY KEY'
ORDER BY K.TABLE_NAME, C.CONSTRAINT_TYPE, K.CONSTRAINT_NAME