Question

在SQL Server中，如何从外键获取引用的表+列名？

注意：不是键所在的表/列，而是键所指的键。

示例：

表[FA_MDT_ID]中的键[T_ALV_Ref_FilterDisplay]。是指[T_AP_Ref_Customer].[MDT_ID]

例如在创建这样的约束时：

ALTER TABLE [dbo].[T_ALV_Ref_FilterDisplay]  WITH CHECK ADD  CONSTRAINT [FK_T_ALV_Ref_FilterDisplay_T_AP_Ref_Customer] FOREIGN KEY([FA_MDT_ID])
REFERENCES [dbo].[T_AP_Ref_Customer] ([MDT_ID])
GO

我需要[T_AP_Ref_Customer].[MDT_ID] 给予[T_ALV_Ref_FilterAnzeige].[FA_MDT_ID]作为输入时

Answer 1

没关系，这是正确答案：
http://msdn.microsoft.com/en-us/library/aa175805(SQL.80).aspx

SELECT  
     KCU1.CONSTRAINT_NAME AS FK_CONSTRAINT_NAME 
    ,KCU1.TABLE_NAME AS FK_TABLE_NAME 
    ,KCU1.COLUMN_NAME AS FK_COLUMN_NAME 
    ,KCU1.ORDINAL_POSITION AS FK_ORDINAL_POSITION 
    ,KCU2.CONSTRAINT_NAME AS REFERENCED_CONSTRAINT_NAME 
    ,KCU2.TABLE_NAME AS REFERENCED_TABLE_NAME 
    ,KCU2.COLUMN_NAME AS REFERENCED_COLUMN_NAME 
    ,KCU2.ORDINAL_POSITION AS REFERENCED_ORDINAL_POSITION 
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC 

INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU1 
    ON KCU1.CONSTRAINT_CATALOG = RC.CONSTRAINT_CATALOG  
    AND KCU1.CONSTRAINT_SCHEMA = RC.CONSTRAINT_SCHEMA 
    AND KCU1.CONSTRAINT_NAME = RC.CONSTRAINT_NAME 

INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU2 
    ON KCU2.CONSTRAINT_CATALOG = RC.UNIQUE_CONSTRAINT_CATALOG  
    AND KCU2.CONSTRAINT_SCHEMA = RC.UNIQUE_CONSTRAINT_SCHEMA 
    AND KCU2.CONSTRAINT_NAME = RC.UNIQUE_CONSTRAINT_NAME 
    AND KCU2.ORDINAL_POSITION = KCU1.ORDINAL_POSITION

Answer 2

如果您可以使用SQL Server特定的架构目录视图，则此查询将返回您要查找的内容：

SELECT  
    fk.name,
    OBJECT_NAME(fk.parent_object_id) 'Parent table',
    c1.name 'Parent column',
    OBJECT_NAME(fk.referenced_object_id) 'Referenced table',
    c2.name 'Referenced column'
FROM 
    sys.foreign_keys fk
INNER JOIN 
    sys.foreign_key_columns fkc ON fkc.constraint_object_id = fk.object_id
INNER JOIN
    sys.columns c1 ON fkc.parent_column_id = c1.column_id AND fkc.parent_object_id = c1.object_id
INNER JOIN
    sys.columns c2 ON fkc.referenced_column_id = c2.column_id AND fkc.referenced_object_id = c2.object_id

不确定 - 如果有的话 - 您可以从INFORMATION_SCHEMA视图中获取相同的信息....

Answer 3

我想要一个版本，让我找到所有“Key”和“ID”列都有/缺少一个约束。所以我希望所有列与所有PK OR FK OR Null的列表进行比较，这是我的查询。希望它可以帮助别人！

SELECT 
     c.table_schema
    ,c.table_name
    ,c.column_name
    ,KeyConstraints.constraint_type
    ,KeyConstraints.constraint_schema
    ,KeyConstraints.constraint_name
    ,KeyConstraints.referenced_table_schema
    ,KeyConstraints.referenced_table_name
    ,KeyConstraints.referenced_column_name
    ,KeyConstraints.update_rule
    ,KeyConstraints.delete_rule
FROM information_schema.columns AS c 
LEFT JOIN 
    (
        SELECT 
             FK.table_schema AS TABLE_SCHEMA
            ,FK.table_name
            ,CU.column_name
            ,FK.constraint_type
            ,c.constraint_schema
            ,C.constraint_name
            ,PK.table_schema AS REFERENCED_TABLE_SCHEMA
            ,PK.table_name AS REFERENCED_TABLE_NAME
            ,CCU.column_name AS REFERENCED_COLUMN_NAME
            ,C.update_rule
            ,C.delete_rule
        FROM information_schema.referential_constraints AS C 

        INNER JOIN information_schema.table_constraints AS FK 
            ON C.constraint_name = FK.constraint_name 

        INNER JOIN information_schema.table_constraints AS PK 
            ON C.unique_constraint_name = PK.constraint_name 

        INNER JOIN information_schema.key_column_usage AS CU 
            ON C.constraint_name = CU.constraint_name 

        INNER JOIN information_schema.constraint_column_usage AS CCU 
            ON PK.constraint_name = CCU.constraint_name 

        WHERE ( FK.constraint_type = 'FOREIGN KEY' ) 

        UNION 

        SELECT 
             ccu.table_schema
            ,ccu.table_name
            ,ccu.column_name
            ,tc.constraint_type
            ,ccu.constraint_schema
            ,ccu.constraint_name
            ,NULL
            ,NULL
            ,NULL
            ,NULL
            ,NULL
        FROM information_schema.constraint_column_usage ccu 

        INNER JOIN information_schema.table_constraints tc 
            ON ccu.table_schema = tc.table_schema 
            AND ccu.table_name = tc.table_name 

        WHERE tc.constraint_type = 'PRIMARY KEY'

    ) AS KeyConstraints 
    ON c.table_schema = KeyConstraints.table_schema 
    AND c.table_name = KeyConstraints.table_name 
    AND c.column_name = KeyConstraints.column_name 

WHERE c.column_name LIKE '%ID' OR c.column_name LIKE '%Key' 
ORDER BY  c.table_schema 
         ,c.table_name 
         ,c.column_name 
;

格式礼貌：http://www.dpriver.com/pp/sqlformat.htm

Answer 4

you can use the following script in order to find all the fk,pk relationship for specific table 

    *DECLARE @tablename VARCHAR(100)
    SET @tablename='xxxxxxx'
    Select 'Referenced by FK table' AS Type,  FK.TABLE_SCHEMA, FK.TABLE_NAME AS 
    'FK_TABLE_NAME' ,cu.COLUMN_NAME AS 'FK_ReferencingColumn',PK.TABLE_NAME AS 
    'PK_TABLE_NAME',
   ku.COLUMN_NAME AS 'PK_ReferencedColumn'
    From INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS As RC
        Join INFORMATION_SCHEMA.TABLE_CONSTRAINTS As PK
            On PK.CONSTRAINT_NAME = RC.UNIQUE_CONSTRAINT_NAME
        Join INFORMATION_SCHEMA.TABLE_CONSTRAINTS As FK
            On FK.CONSTRAINT_NAME = RC.CONSTRAINT_NAME
       JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE cu
       ON cu.CONSTRAINT_NAME = Rc.CONSTRAINT_NAME
         JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE ku
    ON ku.CONSTRAINT_NAME = RC.UNIQUE_CONSTRAINT_NAME
    Where 
        PK.TABLE_NAME = @tablename
    UNION  
    SELECT 'Referencing PK table' AS Type, FK.TABLE_SCHEMA, FK.TABLE_NAME AS 
    'FK_TABLE_NAME' ,cu.COLUMN_NAME AS 'FK_ReferencingColumn',PK.TABLE_NAME AS 
    'PK_TABLE_NAME',
     ku.COLUMN_NAME AS 'PK_ReferencedColumn'
    From INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS As RC
        Join INFORMATION_SCHEMA.TABLE_CONSTRAINTS As PK
            On PK.CONSTRAINT_NAME = RC.UNIQUE_CONSTRAINT_NAME
        Join INFORMATION_SCHEMA.TABLE_CONSTRAINTS As FK
            On FK.CONSTRAINT_NAME = RC.CONSTRAINT_NAME
       JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE cu
       ON cu.CONSTRAINT_NAME = Rc.CONSTRAINT_NAME
         JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE ku
    ON ku.CONSTRAINT_NAME = RC.UNIQUE_CONSTRAINT_NAME
   Where 
        fk.TABLE_NAME = @tablename*

SQL Server：如何从information_schema获取外键引用？

4 个答案: