Sql 如何删除所有表中的所有外键约束?
我想编写sql命令来删除所有表中的所有约束。我在互联网上搜索发现,如果数据库很小且不复杂,那么下面的方法就可以了Sql 如何删除所有表中的所有外键约束?,sql,sql-server,sql-server-2008,Sql,Sql Server,Sql Server 2008,我想编写sql命令来删除所有表中的所有约束。我在互联网上搜索发现,如果数据库很小且不复杂,那么下面的方法就可以了 DECLARE @name VARCHAR(128) DECLARE @constraint VARCHAR(254) DECLARE @SQL VARCHAR(254) DECLARE @schema VARCHAR(128) SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONS
DECLARE @name VARCHAR(128)
DECLARE @constraint VARCHAR(254)
DECLARE @SQL VARCHAR(254)
DECLARE @schema VARCHAR(128)
SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' ORDER BY TABLE_NAME)
SELECT @schema = (SELECT TOP 1 schema_name(schema_id) FROM sys.objects WHERE [name] = @name)
WHILE @name is not null
BEGIN
SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' AND TABLE_NAME = @name ORDER BY CONSTRAINT_NAME)
WHILE @constraint IS NOT NULL
BEGIN
SELECT @SQL = 'ALTER TABLE ' + @schema + '.[' + RTRIM(@name) +'] DROP CONSTRAINT [' + RTRIM(@constraint) +']'
EXEC (@SQL)
PRINT 'Dropped FK Constraint: ' + @constraint + ' on ' + @name
SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' AND CONSTRAINT_NAME <> @constraint AND TABLE_NAME = @name ORDER BY CONSTRAINT_NAME)
END
SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'FOREIGN KEY' ORDER BY TABLE_NAME)
SELECT @schema = (SELECT TOP 1 schema_name(schema_id) FROM sys.objects WHERE [name] = @name)
END
GO
原因是某些FK被其他表引用。我必须运行这个脚本几次,直到数据库干净为止
我想知道如何清除数据库中的所有FK。关于该主题的信息很多。由@AaronBertrand检查。它谈到暂时禁用外键,但阅读所有外键并随意修改,您将有一个很好的脚本可以玩,并取得很多成果 从我的角度来看,我可以提出两种不同的脚本来获取所有外键。在这两种情况下,取消对-EXEC@SQL的注释以执行ALTER代码。或者,您可以等到它打印所有alter子句,然后复制粘贴以执行它们 第一种方法使用信息模式获取约束:
DECLARE @SQL VARCHAR(MAX)=''
SELECT @SQL = @SQL + 'ALTER TABLE ' + QUOTENAME(FK.TABLE_SCHEMA) + '.' + QUOTENAME(FK.TABLE_NAME) + ' DROP CONSTRAINT [' + RTRIM(C.CONSTRAINT_NAME) +'];' + CHAR(13)
--SELECT K_Table = FK.TABLE_NAME, FK_Column = CU.COLUMN_NAME, PK_Table = PK.TABLE_NAME, PK_Column = PT.COLUMN_NAME, Constraint_Name = C.CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU
ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
INNER JOIN (
SELECT i1.TABLE_NAME, i2.COLUMN_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2
ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
) PT
ON PT.TABLE_NAME = PK.TABLE_NAME
--EXEC (@SQL)
PRINT @SQL
这一个使用不同的系统视图和CTE表
DECLARE @SQL varchar(4000)=''
;WITH ReferencingFK AS
(
SELECT fk.Name AS 'FKName', OBJECT_NAME(fk.parent_object_id) 'ParentTable',
cpa.name 'ParentColumnName', OBJECT_NAME(fk.referenced_object_id) 'ReferencedTable',
cref.name 'ReferencedColumnName'
FROM sys.foreign_keys fk
INNER JOIN sys.foreign_key_columns fkc ON fkc.constraint_object_id = fk.object_id
INNER JOIN sys.columns cpa ON fkc.parent_object_id = cpa.object_id AND fkc.parent_column_id = cpa.column_id
INNER JOIN sys.columns cref ON fkc.referenced_object_id = cref.object_id AND fkc.referenced_column_id = cref.column_id
)
SELECT @SQL = @SQL + 'ALTER TABLE ' + ParentTable + ' DROP CONSTRAINT [' + RTRIM(FKName) +'];' + CHAR(13)
--SELECT FKName, ParentTable, ParentColumnName, ReferencedTable, ReferencedColumnName
FROM ReferencingFK
WHERE ReferencedTable = 'Employee'
ORDER BY ParentTable, ReferencedTable, FKName
--EXEC (@SQL)
PRINT @SQL
最简单的变体:
DECLARE @sql nvarchar(MAX)
SET @sql = N''
SELECT @sql = @sql + N'ALTER TABLE ' + QUOTENAME(KCU1.TABLE_SCHEMA)
+ N'.' + QUOTENAME(KCU1.TABLE_NAME)
+ N' DROP CONSTRAINT ' -- + QUOTENAME(rc.CONSTRAINT_SCHEMA) + N'.' -- not in MS-SQL
+ QUOTENAME(rc.CONSTRAINT_NAME) + N'; ' + CHAR(13) + CHAR(10)
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
-- PRINT @sql
EXECUTE(@sql)
我改进了@Yaroslav提供的第一个脚本和@Quandary提供的脚本,因此它们现在适用于SQL查询逐个删除所有外键的大小超过分配给SQL变量4000或最多字符的数据库 为了安全起见,修改后的脚本在每次迭代中删除5个外键,通过添加前5个来实现。当没有外键可供删除时,脚本停止。SQL变量在运行SELECT后保持为空 @Yaroslav的第一个脚本
DECLARE @SQL varchar(4000)
IterationStart:
SET @SQL=''
SELECT TOP 5 @SQL = @SQL + 'ALTER TABLE ' + FK.TABLE_NAME + ' DROP CONSTRAINT [' + RTRIM(C.CONSTRAINT_NAME) +'];' + CHAR(13)
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU
ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
INNER JOIN (
SELECT i1.TABLE_NAME, i2.COLUMN_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2
ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
) PT
ON PT.TABLE_NAME = PK.TABLE_NAME
IF @SQL <> ''
BEGIN
EXEC(@SQL)
GOTO IterationStart
END
由@Quandary编写的脚本
DECLARE @sql nvarchar(MAX)
IterationStart:
SET @sql = ''
SELECT TOP 5 @sql = @sql + 'ALTER TABLE ' + QUOTENAME(RC.CONSTRAINT_SCHEMA)
+ '.' + QUOTENAME(KCU1.TABLE_NAME)
+ ' DROP CONSTRAINT ' + QUOTENAME(rc.CONSTRAINT_NAME) + '; '
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
IF @SQL <> ''
BEGIN
EXEC(@SQL)
GOTO IterationStart
END
我使用了@Yaroslav提到的INFORMATION_模式解决方案,但数据库中的外键常量太多,无法将它们全部放入varcharMAX中。因此,我不得不修改脚本以使用临时表和游标 另外,我在表名周围添加了[]
DECLARE @SQL TABLE (Command VARCHAR(MAX))
INSERT @SQL
SELECT 'ALTER TABLE [' + FK.TABLE_NAME + '] DROP CONSTRAINT [' + RTRIM(C.CONSTRAINT_NAME) +'];' + CHAR(13)
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK
ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK
ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU
ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
INNER JOIN (
SELECT i1.TABLE_NAME, i2.COLUMN_NAME
FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS i1
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE i2
ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME
WHERE i1.CONSTRAINT_TYPE = 'PRIMARY KEY'
) PT
ON PT.TABLE_NAME = PK.TABLE_NAME
DECLARE cmdCursor CURSOR
FOR SELECT Command FROM @SQL
OPEN cmdCursor
DECLARE @Command VARCHAR(MAX)
FETCH NEXT FROM cmdCursor INTO @Command
WHILE @@FETCH_STATUS = 0
BEGIN
PRINT @Command
EXEC (@Command)
FETCH NEXT FROM cmdCursor INTO @Command
END
CLOSE cmdCursor;
DEALLOCATE cmdCursor;
下面是我在SQL Server 2008及更高版本上使用的一个简短脚本,用于删除所有也考虑对象架构的外键:
declare @sql nvarchar(max) = (
select
'alter table ' + quotename(schema_name(schema_id)) + '.' +
quotename(object_name(parent_object_id)) +
' drop constraint '+quotename(name) + ';'
from sys.foreign_keys
for xml path('')
);
exec sp_executesql @sql;
从这个链接可以看到皮纳尔的答案,这非常有帮助
根据您的标题,您希望删除外键。但是,您的最后一个问题要求对所有内容进行清楚的说明,包括表、存储过程和函数。你这是什么意思?虽然我肯定,你一定已经检查过类似的问题,但我想请你重新审视一下这里的解决方案:@Yaroslav谢谢你指出。我满负荷的任务。我只是更新我的问题细节,使其与标题匹配。它产生的结果与我的查询相同。Msg 2801,16级,状态1,程序XXX,第31行对象“XXX”的定义自编译以来发生了变化。虽然此代码可以回答问题,提供有关此代码为什么和/或如何回答此问题的其他上下文可提高其长期价值。对于具有许多约束的数据库,其他提到的解决方案失败,但此解决方案对我有效。您应该使用varcharmax和“ALTER TABLE”+QUOTENAMEFK.TABLE“u SCHEMA+”。+QUOTENAMEFK.TABLE“u NAME+”以避免语法错误。这工作得很好。请注意,在SQL Server Express Edition上,您需要将参数定义为nvarchar,使用varchar将引发以下错误:过程需要类型为“ntext/nchar/nvarchar”的参数“@statement”。某些最新的SQL Server版本也可能如此,但我无法进行测试。我在您的答案中使用了@Quandary的脚本,它工作得非常好。荣誉
CREATE TABLE #Commands (Command VARCHAR(MAX))
INSERT #Commands
SELECT 'ALTER TABLE ' + QUOTENAME(RC.CONSTRAINT_SCHEMA)
+ '.' + QUOTENAME(KCU1.TABLE_NAME)
+ ' DROP CONSTRAINT ' + QUOTENAME(rc.CONSTRAINT_NAME) + '; '
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
WHERE ORDINAL_POSITION=1
--SELECT * FROM #Commands
DECLARE @Command VARCHAR(MAX)
DECLARE curCommand CURSOR FOR
SELECT Command FROM #Commands
OPEN curCommand
FETCH NEXT FROM curCommand INTO @Command
WHILE @@FETCH_STATUS =0
BEGIN
EXEC(@Command)
FETCH NEXT FROM curCommand INTO @Command
END
CLOSE curCommand
DEALLOCATE curCommand
DROP TABLE #Commands
declare @sql nvarchar(max) = (
select
'alter table ' + quotename(schema_name(schema_id)) + '.' +
quotename(object_name(parent_object_id)) +
' drop constraint '+quotename(name) + ';'
from sys.foreign_keys
for xml path('')
);
exec sp_executesql @sql;
SET NOCOUNT ON
DECLARE @table TABLE(
RowId INT PRIMARY KEY IDENTITY(1, 1),
ForeignKeyConstraintName NVARCHAR(200),
ForeignKeyConstraintTableSchema NVARCHAR(200),
ForeignKeyConstraintTableName NVARCHAR(200),
ForeignKeyConstraintColumnName NVARCHAR(200),
PrimaryKeyConstraintName NVARCHAR(200),
PrimaryKeyConstraintTableSchema NVARCHAR(200),
PrimaryKeyConstraintTableName NVARCHAR(200),
PrimaryKeyConstraintColumnName NVARCHAR(200)
)
INSERT INTO @table(ForeignKeyConstraintName, ForeignKeyConstraintTableSchema, ForeignKeyConstraintTableName, ForeignKeyConstraintColumnName)
SELECT
U.CONSTRAINT_NAME,
U.TABLE_SCHEMA,
U.TABLE_NAME,
U.COLUMN_NAME
FROM
INFORMATION_SCHEMA.KEY_COLUMN_USAGE U
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS C
ON U.CONSTRAINT_NAME = C.CONSTRAINT_NAME
WHERE
C.CONSTRAINT_TYPE = 'FOREIGN KEY'
UPDATE @table SET
PrimaryKeyConstraintName = UNIQUE_CONSTRAINT_NAME
FROM
@table T
INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS R
ON T.ForeignKeyConstraintName = R.CONSTRAINT_NAME
UPDATE @table SET
PrimaryKeyConstraintTableSchema = TABLE_SCHEMA,
PrimaryKeyConstraintTableName = TABLE_NAME
FROM @table T
INNER JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS C
ON T.PrimaryKeyConstraintName = C.CONSTRAINT_NAME
UPDATE @table SET
PrimaryKeyConstraintColumnName = COLUMN_NAME
FROM @table T
INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE U
ON T.PrimaryKeyConstraintName = U.CONSTRAINT_NAME
--SELECT * FROM @table
--DROP CONSTRAINT:
SELECT
'
ALTER TABLE [' + ForeignKeyConstraintTableSchema + '].[' + ForeignKeyConstraintTableName + ']
DROP CONSTRAINT [' + ForeignKeyConstraintName + ']
GO'
FROM
@table