使用SQL Server 2005如何知道CONSTRAINT_NAME是主键还是外键?
SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_NAME = @TableName
AND [email protected]
这个SQL,我得到了主键和外键。
我怎样才能得到外键? 如何查看约束是主键还是外键?
感谢
使用SQL Server 2005如何知道CONSTRAINT_NAME是主键还是外键?
SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_NAME = @TableName
AND [email protected]
这个SQL,我得到了主键和外键。
我怎样才能得到外键? 如何查看约束是主键还是外键?
感谢
我用下面的SQL与SQL Server 2005,以获得通过主键约束名称:
SELECT Constraint_Name
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS
WHERE UNIQUE_CONSTRAINT_NAME =
(SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_NAME = @TableName AND COLUMN_NAME = @ColumnName)
要通过Foreing重点得到约束名称:
SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_NAME = @TableName AND COLUMN_NAME = @ColumnName
为了得到外键的表和字段的约束名称:
SELECT TABLE_NAME, COLUMN_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE CONSTRAINT_NAME = @ConstraintName
要获取主键的表和字段由C onstraint名称:
SELECT TABLE_NAME, COLUMN_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE CONSTRAINT_NAME =
(SELECT UNIQUE_CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS
WHERE CONSTRAINT_NAME = @ConstraintName)
这取决于你的DBMS,但是约束应该在目标表和列的地方。
如果是外键约束,目标表将与当前表不同。尝试
select *
,而不是
select constraint_name
看到所有你能一起工作的神奇列。
SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_NAME = @TableName
AND [email protected]
AND REFERENCED_COLUMN_NAME IS NOT NULL
这不是最优雅的解决方案,但MS SQL Server使用PK & FK前缀键命名约定,所以你可以使用类似...
SELECT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_NAME = @TableName
AND LEFT(CONSTRAINT_NAME,2) = 'FK'
如果这是你的DBMS :)
编辑
当我试图通过Quassnoi的答案我有一个“无效列名称“REFERENCED_COLUMN_NAME”。“错误。
找到一个更好的解决方案here
代码下面添加的完整性,但都归功于皮纳尔戴夫
SELECT f.name AS ForeignKey,
OBJECT_NAME(f.parent_object_id) AS TableName,
COL_NAME(fc.parent_object_id,
fc.parent_column_id) AS ColumnName,
OBJECT_NAME (f.referenced_object_id) AS ReferenceTableName,
COL_NAME(fc.referenced_object_id,
fc.referenced_column_id) AS ReferenceColumnName
FROM sys.foreign_keys AS f
LEFT JOIN sys.foreign_key_columns AS fc
ON f.OBJECT_ID = fc.constraint_object_id
如果你只是想在主键...
SELECT i.name AS IndexName,
OBJECT_NAME(ic.OBJECT_ID) AS TableName,
COL_NAME(ic.OBJECT_ID,ic.column_id) AS ColumnName
FROM sys.indexes AS i
INNER JOIN sys.index_columns AS ic
ON i.OBJECT_ID = ic.OBJECT_ID
AND i.index_id = ic.index_id
WHERE i.is_primary_key = 1
添加此为一个额外的答案,因为它是从我以前的一个很远:)
我使用类似的东西。它也适用于SQL Server 2000。
select object_name(fkx.constid) as fk_name,
fkx.keyno as num,
object_name(fkx.fkeyid) as child_table,
col_name(fkx.fkeyid, fkx.fkey) as child_column,
object_name(fkx.rkeyid) as parent_table,
col_name(fkx.rkeyid, fkx.rkey) as parent_column
from sysforeignkeys fkx
order by fk_name, fkx.keyno
这一切都在系统表和视图,这是很好的记录。
我使用SQL Server 2005 – 2009-02-17 11:09:39