我需要在SQL Server数据库中删除一个高度引用的表。我如何才能得到所有外键约束的列表，我将需要删除以便删除表?
(SQL比在管理工作室的GUI中点击更可取)
当前回答
with tab_list as (
select t.name AS Table_Name, t.object_id, s.name AS Table_Schema from sys.tables t, sys.schemas s
where t.schema_id = s.schema_id
and s.name = 'your schema')
select IIF(col.column_id = 1, tab.TABLE_SCHEMA + '.' + tab.TABLE_NAME, NULL) Table_Name,
col.Name AS Column_Name, IIF(col.IS_NULLABLE= 0, 'NOT NULL', '') Nullable, st.name Type,
CASE WHEN st.name = 'decimal' THEN CONVERT(NVARCHAR(4000), col.Precision) + ',' + CONVERT(NVARCHAR(4000), col.Scale)
WHEN col.max_length = -1 THEN 'max'
WHEN st.name in ('int', 'bit', 'bigint', 'datetime2') THEN NULL
ELSE CONVERT(NVARCHAR(4000), col.max_length / 2)
END
AS Length,
ss.name + '.' + stab.name Referenced_Table, scol.name Referenced_Column
from sys.COLUMNS col
INNER JOIN tab_list tab ON col.object_id = tab.object_id
INNER JOIN sys.types st ON col.system_type_id = st.system_type_id AND col.user_type_id = st.user_type_id
LEFT JOIN [sys].[foreign_key_columns] sfkc ON col.object_id = sfkc.parent_object_id AND col.column_id = sfkc.parent_column_id
LEFT JOIN sys.tables stab ON sfkc.referenced_object_id = stab.object_id
LEFT JOIN sys.columns scol ON sfkc.referenced_object_id = scol.object_id AND sfkc.referenced_column_id = scol.column_id
LEFT JOIN sys.schemas ss ON ss.schema_id = stab.schema_id
其他回答
这里有如何计算所选Id的所有责任。只需更改@dbTableName值，@dbRowId值及其类型(如果是int，则需要在第82行中删除“..设置@sql = ..))。享受。
DECLARE @dbTableName varchar(max) = 'User'
DECLARE @dbRowId uniqueidentifier = '21d34ecd-c1fd-11e2-8545-002219a42e1c'
DECLARE @FK_ROWCOUNT int
DECLARE @SQL nvarchar(max)
DECLARE @PKTABLE_QUALIFIER sysname
DECLARE @PKTABLE_OWNER sysname
DECLARE @PKTABLE_NAME sysname
DECLARE @PKCOLUMN_NAME sysname
DECLARE @FKTABLE_QUALIFIER sysname
DECLARE @FKTABLE_OWNER sysname
DECLARE @FKTABLE_NAME sysname
DECLARE @FKCOLUMN_NAME sysname
DECLARE @UPDATE_RULE smallint
DECLARE @DELETE_RULE smallint
DECLARE @FK_NAME sysname
DECLARE @PK_NAME sysname
DECLARE @DEFERRABILITY sysname
IF OBJECT_ID('tempdb..#Temp1') IS NOT NULL
DROP TABLE #Temp1;
CREATE TABLE #Temp1 (
PKTABLE_QUALIFIER sysname,
PKTABLE_OWNER sysname,
PKTABLE_NAME sysname,
PKCOLUMN_NAME sysname,
FKTABLE_QUALIFIER sysname,
FKTABLE_OWNER sysname,
FKTABLE_NAME sysname,
FKCOLUMN_NAME sysname,
UPDATE_RULE smallint,
DELETE_RULE smallint,
FK_NAME sysname,
PK_NAME sysname,
DEFERRABILITY sysname,
FK_ROWCOUNT int
);
DECLARE FK_Counter_Cursor CURSOR FOR
SELECT PKTABLE_QUALIFIER = CONVERT(SYSNAME,DB_NAME()),
PKTABLE_OWNER = CONVERT(SYSNAME,SCHEMA_NAME(O1.SCHEMA_ID)),
PKTABLE_NAME = CONVERT(SYSNAME,O1.NAME),
PKCOLUMN_NAME = CONVERT(SYSNAME,C1.NAME),
FKTABLE_QUALIFIER = CONVERT(SYSNAME,DB_NAME()),
FKTABLE_OWNER = CONVERT(SYSNAME,SCHEMA_NAME(O2.SCHEMA_ID)),
FKTABLE_NAME = CONVERT(SYSNAME,O2.NAME),
FKCOLUMN_NAME = CONVERT(SYSNAME,C2.NAME),
-- Force the column to be non-nullable (see SQL BU 325751)
--KEY_SEQ = isnull(convert(smallint,k.constraint_column_id), sysconv(smallint,0)),
UPDATE_RULE = CONVERT(SMALLINT,CASE OBJECTPROPERTY(F.OBJECT_ID,'CnstIsUpdateCascade')
WHEN 1 THEN 0
ELSE 1
END),
DELETE_RULE = CONVERT(SMALLINT,CASE OBJECTPROPERTY(F.OBJECT_ID,'CnstIsDeleteCascade')
WHEN 1 THEN 0
ELSE 1
END),
FK_NAME = CONVERT(SYSNAME,OBJECT_NAME(F.OBJECT_ID)),
PK_NAME = CONVERT(SYSNAME,I.NAME),
DEFERRABILITY = CONVERT(SMALLINT,7) -- SQL_NOT_DEFERRABLE
FROM SYS.ALL_OBJECTS O1,
SYS.ALL_OBJECTS O2,
SYS.ALL_COLUMNS C1,
SYS.ALL_COLUMNS C2,
SYS.FOREIGN_KEYS F
INNER JOIN SYS.FOREIGN_KEY_COLUMNS K
ON (K.CONSTRAINT_OBJECT_ID = F.OBJECT_ID)
INNER JOIN SYS.INDEXES I
ON (F.REFERENCED_OBJECT_ID = I.OBJECT_ID
AND F.KEY_INDEX_ID = I.INDEX_ID)
WHERE O1.OBJECT_ID = F.REFERENCED_OBJECT_ID
AND O2.OBJECT_ID = F.PARENT_OBJECT_ID
AND C1.OBJECT_ID = F.REFERENCED_OBJECT_ID
AND C2.OBJECT_ID = F.PARENT_OBJECT_ID
AND C1.COLUMN_ID = K.REFERENCED_COLUMN_ID
AND C2.COLUMN_ID = K.PARENT_COLUMN_ID
AND O1.NAME = @dbTableName
OPEN FK_Counter_Cursor;
FETCH NEXT FROM FK_Counter_Cursor INTO @PKTABLE_QUALIFIER, @PKTABLE_OWNER, @PKTABLE_NAME, @PKCOLUMN_NAME, @FKTABLE_QUALIFIER, @FKTABLE_OWNER, @FKTABLE_NAME, @FKCOLUMN_NAME, @UPDATE_RULE, @DELETE_RULE, @FK_NAME, @PK_NAME, @DEFERRABILITY;
WHILE @@FETCH_STATUS = 0
BEGIN
SET @SQL = 'SELECT @dbCountOut = COUNT(*) FROM [' + @FKTABLE_NAME + '] WHERE [' + @FKCOLUMN_NAME + '] = ''' + CAST(@dbRowId AS varchar(max)) + '''';
EXECUTE sp_executesql @SQL, N'@dbCountOut int OUTPUT', @dbCountOut = @FK_ROWCOUNT OUTPUT;
INSERT INTO #Temp1 (PKTABLE_QUALIFIER, PKTABLE_OWNER, PKTABLE_NAME, PKCOLUMN_NAME, FKTABLE_QUALIFIER, FKTABLE_OWNER, FKTABLE_NAME, FKCOLUMN_NAME, UPDATE_RULE, DELETE_RULE, FK_NAME, PK_NAME, DEFERRABILITY, FK_ROWCOUNT) VALUES (@FKTABLE_QUALIFIER, @PKTABLE_OWNER, @PKTABLE_NAME, @PKCOLUMN_NAME, @FKTABLE_QUALIFIER, @FKTABLE_OWNER, @FKTABLE_NAME, @FKCOLUMN_NAME, @UPDATE_RULE, @DELETE_RULE, @FK_NAME, @PK_NAME, @DEFERRABILITY, @FK_ROWCOUNT)
FETCH NEXT FROM FK_Counter_Cursor INTO @PKTABLE_QUALIFIER, @PKTABLE_OWNER, @PKTABLE_NAME, @PKCOLUMN_NAME, @FKTABLE_QUALIFIER, @FKTABLE_OWNER, @FKTABLE_NAME, @FKCOLUMN_NAME, @UPDATE_RULE, @DELETE_RULE, @FK_NAME, @PK_NAME, @DEFERRABILITY;
END;
CLOSE FK_Counter_Cursor;
DEALLOCATE FK_Counter_Cursor;
GO
SELECT * FROM #Temp1
GO
上面有一些不错的答案。但我更喜欢一个问题就能得到答案。 这段代码来自sys. .Sp_helpconstraint (sys proc)
这是微软查找是否有与tbl关联的外键的方法。
--setup variables. Just change 'Customer' to tbl you want
declare @objid int,
@objname nvarchar(776)
select @objname = 'Customer'
select @objid = object_id(@objname)
if exists (select * from sys.foreign_keys where referenced_object_id = @objid)
select 'Table is referenced by foreign key' =
db_name() + '.'
+ rtrim(schema_name(ObjectProperty(parent_object_id,'schemaid')))
+ '.' + object_name(parent_object_id)
+ ': ' + object_name(object_id)
from sys.foreign_keys
where referenced_object_id = @objid
order by 1
答案看起来像这样:test_db_name.dbo。账户:FK_Account_Customer
你可以通过以下查询找到:
SELECT OBJECT_NAME (FK.referenced_object_id) 'Referenced Table',
OBJECT_NAME(FK.parent_object_id) 'Referring Table', FK.name 'Foreign Key',
COL_NAME(FK.referenced_object_id, FKC.referenced_column_id) 'Referenced Column',
COL_NAME(FK.parent_object_id,FKC.parent_column_id) 'Referring Column'
FROM sys.foreign_keys AS FK
INNER JOIN sys.foreign_key_columns AS FKC
ON FKC.constraint_object_id = FK.OBJECT_ID
WHERE OBJECT_NAME (FK.referenced_object_id) = 'YourTableName'
AND COL_NAME(FK.referenced_object_id, FKC.referenced_column_id) = 'YourColumnName'
order by OBJECT_NAME(FK.parent_object_id)
SELECT OBJECT_NAME(fk.parent_object_id) as ReferencingTable,
OBJECT_NAME(fk.constraint_object_id) as [FKContraint]
FROM sys.foreign_key_columns as fk
WHERE fk.referenced_object_id = OBJECT_ID('ReferencedTable', 'U')
这只显示了外键约束的关系。我的数据库显然早于FK约束。一些表使用触发器来强制引用完整性，有时除了一个类似命名的列来指示关系之外什么都没有(根本没有引用完整性)。
幸运的是，我们有一个一致的命名场景，所以我能够找到引用表 观点是这样的:
SELECT OBJECT_NAME(object_id) from sys.columns where name like 'client_id'
我使用这个选择作为生成一个脚本的基础，做我需要做的事情 相关的表格。
SELECT
OBJECT_NAME(parent_object_id) 'Parent table',
c.NAME 'Parent column name',
OBJECT_NAME(referenced_object_id) 'Referenced table',
cref.NAME 'Referenced column name'
FROM
sys.foreign_key_columns fkc
INNER JOIN
sys.columns c
ON fkc.parent_column_id = c.column_id
AND fkc.parent_object_id = c.object_id
INNER JOIN
sys.columns cref
ON fkc.referenced_column_id = cref.column_id
AND fkc.referenced_object_id = cref.object_id where OBJECT_NAME(parent_object_id) = 'tablename'
如果你想获得所有表的外键关系，排除where子句，否则写你的tablename而不是tablename
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