是否禁用和启用SQL Server支持的外键约束？或者是我唯一的选择drop,然后重新create约束？
如果要禁用数据库中的所有约束,只需运行以下代码:
-- disable all constraints EXEC sp_MSforeachtable "ALTER TABLE ? NOCHECK CONSTRAINT all"
要重新打开它们,请运行:(打印是可选的,当然只是列出表格)
-- enable all constraints exec sp_MSforeachtable @command1="print '?'", @command2="ALTER TABLE ? WITH CHECK CHECK CONSTRAINT all"
我发现将数据从一个数据库填充到另一个数据库时很有用.这比删除约束要好得多.正如您所提到的,在将所有数据放入数据库并重新填充数据库时(例如在测试环境中),它非常方便.
如果要删除所有数据,可以找到此解决方案很有帮助.
有时也可以方便地禁用所有触发器,您可以在此处查看完整的解决方案.
http://www.sqljunkies.com/WebLog/roman/archive/2005/01/30/7037.aspx
-- Disable all table constraints ALTER TABLE MyTable NOCHECK CONSTRAINT ALL -- Enable all table constraints ALTER TABLE MyTable WITH CHECK CHECK CONSTRAINT ALL -- Disable single constraint ALTER TABLE MyTable NOCHECK CONSTRAINT MyConstraint -- Enable single constraint ALTER TABLE MyTable WITH CHECK CHECK CONSTRAINT MyConstraint
要禁用约束,请使用NOCHECK更改表
ALTER TABLE [TABLE_NAME] NOCHECK CONSTRAINT [ALL|CONSTRAINT_NAME]
要使您必须使用双重检查
ALTER TABLE [TABLE_NAME] WITH CHECK CHECK CONSTRAINT [ALL|CONSTRAINT_NAME]
启用时请注意双重CHECK CHECK.
ALL表示表中的所有约束.
完成后,如果需要检查状态,请使用此脚本列出约束状态.会非常有帮助:
SELECT (CASE
WHEN OBJECTPROPERTY(CONSTID, 'CNSTISDISABLED') = 0 THEN 'ENABLED'
ELSE 'DISABLED'
END) AS STATUS,
OBJECT_NAME(CONSTID) AS CONSTRAINT_NAME,
OBJECT_NAME(FKEYID) AS TABLE_NAME,
COL_NAME(FKEYID, FKEY) AS COLUMN_NAME,
OBJECT_NAME(RKEYID) AS REFERENCED_TABLE_NAME,
COL_NAME(RKEYID, RKEY) AS REFERENCED_COLUMN_NAME
FROM SYSFOREIGNKEYS
ORDER BY TABLE_NAME, CONSTRAINT_NAME,REFERENCED_TABLE_NAME, KEYNO
您最好的选择是DROP和CREATE外键约束.
我没有在这篇文章中找到可以"按原样"为我工作的例子,如果外键引用不同的模式,则无法工作,如果外键引用多个列,则另一个不起作用.此脚本同时考虑每个外键的多个模式和多个列.
这是生成"ADD CONSTRAINT"语句的脚本,对于多个列,它将用逗号分隔它们(确保在执行DROP语句之前保存此输出):
PRINT N'-- CREATE FOREIGN KEY CONSTRAINTS --';
SET NOCOUNT ON;
SELECT '
PRINT N''Creating '+ const.const_name +'...''
GO
ALTER TABLE ' + const.parent_obj + '
ADD CONSTRAINT ' + const.const_name + ' FOREIGN KEY (
' + const.parent_col_csv + '
) REFERENCES ' + const.ref_obj + '(' + const.ref_col_csv + ')
GO'
FROM (
SELECT QUOTENAME(fk.NAME) AS [const_name]
,QUOTENAME(schParent.NAME) + '.' + QUOTENAME(OBJECT_name(fkc.parent_object_id)) AS [parent_obj]
,STUFF((
SELECT ',' + QUOTENAME(COL_NAME(fcP.parent_object_id, fcp.parent_column_id))
FROM sys.foreign_key_columns AS fcP
WHERE fcp.constraint_object_id = fk.object_id
FOR XML path('')
), 1, 1, '') AS [parent_col_csv]
,QUOTENAME(schRef.NAME) + '.' + QUOTENAME(OBJECT_NAME(fkc.referenced_object_id)) AS [ref_obj]
,STUFF((
SELECT ',' + QUOTENAME(COL_NAME(fcR.referenced_object_id, fcR.referenced_column_id))
FROM sys.foreign_key_columns AS fcR
WHERE fcR.constraint_object_id = fk.object_id
FOR XML path('')
), 1, 1, '') AS [ref_col_csv]
FROM sys.foreign_key_columns AS fkc
INNER JOIN sys.foreign_keys AS fk ON fk.object_id = fkc.constraint_object_id
INNER JOIN sys.objects AS oParent ON oParent.object_id = fkc.parent_object_id
INNER JOIN sys.schemas AS schParent ON schParent.schema_id = oParent.schema_id
INNER JOIN sys.objects AS oRef ON oRef.object_id = fkc.referenced_object_id
INNER JOIN sys.schemas AS schRef ON schRef.schema_id = oRef.schema_id
GROUP BY fkc.parent_object_id
,fkc.referenced_object_id
,fk.NAME
,fk.object_id
,schParent.NAME
,schRef.NAME
) AS const
ORDER BY const.const_name
以下是生成"DROP CONSTRAINT"语句的脚本:
PRINT N'-- DROP FOREIGN KEY CONSTRAINTS --'; SET NOCOUNT ON; SELECT ' PRINT N''Dropping ' + fk.NAME + '...'' GO ALTER TABLE [' + sch.NAME + '].[' + OBJECT_NAME(fk.parent_object_id) + ']' + ' DROP CONSTRAINT ' + '[' + fk.NAME + '] GO' FROM sys.foreign_keys AS fk INNER JOIN sys.schemas AS sch ON sch.schema_id = fk.schema_id ORDER BY fk.NAME
SQL-92标准允许将constaint声明为DEFERRABLE,以便可以在事务范围内延迟(隐式或显式).遗憾的是,SQL Server仍然缺少这种SQL-92功能.
对我来说,将约束更改为NOCHECK类似于在飞行中更改数据库结构 - 确实是 - 并且需要避免的事情(例如,用户需要增加的权限).
--Drop and Recreate Foreign Key Constraints
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
--ADD CONSTRAINT:
SELECT
'
ALTER TABLE [' + ForeignKeyConstraintTableSchema + '].[' + ForeignKeyConstraintTableName + ']
ADD CONSTRAINT ' + ForeignKeyConstraintName + ' FOREIGN KEY(' + ForeignKeyConstraintColumnName + ') REFERENCES [' + PrimaryKeyConstraintTableSchema + '].[' + PrimaryKeyConstraintTableName + '](' + PrimaryKeyConstraintColumnName + ')
GO'
FROM
@table
GO
哈林,我同意你的看法.当您使用SSIS传输数据或想要复制数据时,似乎必须暂时禁用或删除外键约束,然后重新启用或重新创建它们.在这些情况下,引用完整性不是问题,因为它已在源数据库中维护.因此,您可以放心这件事.
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),
UpdateRule NVARCHAR(100),
DeleteRule NVARCHAR(100)
)
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
T.PrimaryKeyConstraintName = R.UNIQUE_CONSTRAINT_NAME,
T.UpdateRule = R.UPDATE_RULE,
T.DeleteRule = R.DELETE_RULE
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
SELECT '
BEGIN TRANSACTION
BEGIN TRY'
--DROP CONSTRAINT:
SELECT
'
ALTER TABLE [' + ForeignKeyConstraintTableSchema + '].[' + ForeignKeyConstraintTableName + ']
DROP CONSTRAINT ' + ForeignKeyConstraintName + '
'
FROM
@table
SELECT '
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
RAISERROR(''Operation failed.'', 16, 1)
END CATCH
IF(@@TRANCOUNT != 0)
BEGIN
COMMIT TRANSACTION
RAISERROR(''Operation completed successfully.'', 10, 1)
END
'
--ADD CONSTRAINT:
SELECT '
BEGIN TRANSACTION
BEGIN TRY'
SELECT
'
ALTER TABLE [' + ForeignKeyConstraintTableSchema + '].[' + ForeignKeyConstraintTableName + ']
ADD CONSTRAINT ' + ForeignKeyConstraintName + ' FOREIGN KEY(' + ForeignKeyConstraintColumnName + ') REFERENCES [' + PrimaryKeyConstraintTableSchema + '].[' + PrimaryKeyConstraintTableName + '](' + PrimaryKeyConstraintColumnName + ') ON UPDATE ' + UpdateRule + ' ON DELETE ' + DeleteRule + '
'
FROM
@table
SELECT '
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION
RAISERROR(''Operation failed.'', 16, 1)
END CATCH
IF(@@TRANCOUNT != 0)
BEGIN
COMMIT TRANSACTION
RAISERROR(''Operation completed successfully.'', 10, 1)
END'
GO
第一篇文章:)
对于OP,kristof的解决方案将起作用,除非在大删除上存在大量数据和事务日志气球问题.此外,即使使用tlog存储,由于删除写入tlog,因此对于具有数亿行的表,操作可能需要很长时间.
我使用一系列游标来频繁截断并重新加载我们庞大的生产数据库的大型副本.该解决方案设计了多个模式,多个外键列,最重要的是可以在SSIS中使用.
它涉及创建三个临时表(实际表)以容纳DROP,CREATE和CHECK FK脚本,创建这些脚本并将其插入表中,然后循环遍历表并执行它们.附加的脚本分为四个部分:1.)在三个临时(实际)表中创建和存储脚本,2.通过游标逐个执行drop FK脚本,3.)使用sp_MSforeachtable截断所有除了我们的三个临时表之外的数据库中的表和4.)执行create FK并检查ETL SSIS包末尾的FK脚本.
在SSIS中的"执行SQL"任务中运行脚本创建部分.在第二个执行SQL任务中运行"execute Drop FK Scripts"部分.将截断脚本放在第三个执行SQL任务中,然后在控制流结束时将CREATE和CHECK脚本附加到最终的执行SQL任务(或两个,如果需要)之前,执行您需要执行的任何其他ETL过程.
当重新应用外键失败时,实际表中脚本的存储已被证明是非常宝贵的,因为您可以从sync_CreateFK中选择*,复制/粘贴到查询窗口,一次运行一个,并在您修复数据问题后找到失败/仍未能重新申请的人.
如果脚本失败而不确保在执行此操作之前重新应用所有外键/检查,请不要再次重新运行脚本,否则您很可能会丢失一些创建并检查fk脚本,因为我们的登台表已被删除在创建要执行的脚本之前重新创建.
----------------------------------------------------------------------------
1)
/*
Author: Denmach
DateCreated: 2014-04-23
Purpose: Generates SQL statements to DROP, ADD, and CHECK existing constraints for a
database. Stores scripts in tables on target database for execution. Executes
those stored scripts via independent cursors.
DateModified:
ModifiedBy
Comments: This will eliminate deletes and the T-log ballooning associated with it.
*/
DECLARE @schema_name SYSNAME;
DECLARE @table_name SYSNAME;
DECLARE @constraint_name SYSNAME;
DECLARE @constraint_object_id INT;
DECLARE @referenced_object_name SYSNAME;
DECLARE @is_disabled BIT;
DECLARE @is_not_for_replication BIT;
DECLARE @is_not_trusted BIT;
DECLARE @delete_referential_action TINYINT;
DECLARE @update_referential_action TINYINT;
DECLARE @tsql NVARCHAR(4000);
DECLARE @tsql2 NVARCHAR(4000);
DECLARE @fkCol SYSNAME;
DECLARE @pkCol SYSNAME;
DECLARE @col1 BIT;
DECLARE @action CHAR(6);
DECLARE @referenced_schema_name SYSNAME;
--------------------------------Generate scripts to drop all foreign keys in a database --------------------------------
IF OBJECT_ID('dbo.sync_dropFK') IS NOT NULL
DROP TABLE sync_dropFK
CREATE TABLE sync_dropFK
(
ID INT IDENTITY (1,1) NOT NULL
, Script NVARCHAR(4000)
)
DECLARE FKcursor CURSOR FOR
SELECT
OBJECT_SCHEMA_NAME(parent_object_id)
, OBJECT_NAME(parent_object_id)
, name
FROM
sys.foreign_keys WITH (NOLOCK)
ORDER BY
1,2;
OPEN FKcursor;
FETCH NEXT FROM FKcursor INTO
@schema_name
, @table_name
, @constraint_name
WHILE @@FETCH_STATUS = 0
BEGIN
SET @tsql = 'ALTER TABLE '
+ QUOTENAME(@schema_name)
+ '.'
+ QUOTENAME(@table_name)
+ ' DROP CONSTRAINT '
+ QUOTENAME(@constraint_name)
+ ';';
--PRINT @tsql;
INSERT sync_dropFK (
Script
)
VALUES (
@tsql
)
FETCH NEXT FROM FKcursor INTO
@schema_name
, @table_name
, @constraint_name
;
END;
CLOSE FKcursor;
DEALLOCATE FKcursor;
---------------Generate scripts to create all existing foreign keys in a database --------------------------------
----------------------------------------------------------------------------------------------------------
IF OBJECT_ID('dbo.sync_createFK') IS NOT NULL
DROP TABLE sync_createFK
CREATE TABLE sync_createFK
(
ID INT IDENTITY (1,1) NOT NULL
, Script NVARCHAR(4000)
)
IF OBJECT_ID('dbo.sync_createCHECK') IS NOT NULL
DROP TABLE sync_createCHECK
CREATE TABLE sync_createCHECK
(
ID INT IDENTITY (1,1) NOT NULL
, Script NVARCHAR(4000)
)
DECLARE FKcursor CURSOR FOR
SELECT
OBJECT_SCHEMA_NAME(parent_object_id)
, OBJECT_NAME(parent_object_id)
, name
, OBJECT_NAME(referenced_object_id)
, OBJECT_ID
, is_disabled
, is_not_for_replication
, is_not_trusted
, delete_referential_action
, update_referential_action
, OBJECT_SCHEMA_NAME(referenced_object_id)
FROM
sys.foreign_keys WITH (NOLOCK)
ORDER BY
1,2;
OPEN FKcursor;
FETCH NEXT FROM FKcursor INTO
@schema_name
, @table_name
, @constraint_name
, @referenced_object_name
, @constraint_object_id
, @is_disabled
, @is_not_for_replication
, @is_not_trusted
, @delete_referential_action
, @update_referential_action
, @referenced_schema_name;
WHILE @@FETCH_STATUS = 0
BEGIN
BEGIN
SET @tsql = 'ALTER TABLE '
+ QUOTENAME(@schema_name)
+ '.'
+ QUOTENAME(@table_name)
+ CASE
@is_not_trusted
WHEN 0 THEN ' WITH CHECK '
ELSE ' WITH NOCHECK '
END
+ ' ADD CONSTRAINT '
+ QUOTENAME(@constraint_name)
+ ' FOREIGN KEY (';
SET @tsql2 = '';
DECLARE ColumnCursor CURSOR FOR
SELECT
COL_NAME(fk.parent_object_id
, fkc.parent_column_id)
, COL_NAME(fk.referenced_object_id
, fkc.referenced_column_id)
FROM
sys.foreign_keys fk WITH (NOLOCK)
INNER JOIN sys.foreign_key_columns fkc WITH (NOLOCK) ON fk.[object_id] = fkc.constraint_object_id
WHERE
fkc.constraint_object_id = @constraint_object_id
ORDER BY
fkc.constraint_column_id;
OPEN ColumnCursor;
SET @col1 = 1;
FETCH NEXT FROM ColumnCursor INTO @fkCol, @pkCol;
WHILE @@FETCH_STATUS = 0
BEGIN
IF (@col1 = 1)
SET @col1 = 0;
ELSE
BEGIN
SET @tsql = @tsql + ',';
SET @tsql2 = @tsql2 + ',';
END;
SET @tsql = @tsql + QUOTENAME(@fkCol);
SET @tsql2 = @tsql2 + QUOTENAME(@pkCol);
--PRINT '@tsql = ' + @tsql
--PRINT '@tsql2 = ' + @tsql2
FETCH NEXT FROM ColumnCursor INTO @fkCol, @pkCol;
--PRINT 'FK Column ' + @fkCol
--PRINT 'PK Column ' + @pkCol
END;
CLOSE ColumnCursor;
DEALLOCATE ColumnCursor;
SET @tsql = @tsql + ' ) REFERENCES '
+ QUOTENAME(@referenced_schema_name)
+ '.'
+ QUOTENAME(@referenced_object_name)
+ ' ('
+ @tsql2 + ')';
SET @tsql = @tsql
+ ' ON UPDATE '
+
CASE @update_referential_action
WHEN 0 THEN 'NO ACTION '
WHEN 1 THEN 'CASCADE '
WHEN 2 THEN 'SET NULL '
ELSE 'SET DEFAULT '
END
+ ' ON DELETE '
+
CASE @delete_referential_action
WHEN 0 THEN 'NO ACTION '
WHEN 1 THEN 'CASCADE '
WHEN 2 THEN 'SET NULL '
ELSE 'SET DEFAULT '
END
+
CASE @is_not_for_replication
WHEN 1 THEN ' NOT FOR REPLICATION '
ELSE ''
END
+ ';';
END;
-- PRINT @tsql
INSERT sync_createFK
(
Script
)
VALUES (
@tsql
)
-------------------Generate CHECK CONSTRAINT scripts for a database ------------------------------
----------------------------------------------------------------------------------------------------------
BEGIN
SET @tsql = 'ALTER TABLE '
+ QUOTENAME(@schema_name)
+ '.'
+ QUOTENAME(@table_name)
+
CASE @is_disabled
WHEN 0 THEN ' CHECK '
ELSE ' NOCHECK '
END
+ 'CONSTRAINT '
+ QUOTENAME(@constraint_name)
+ ';';
--PRINT @tsql;
INSERT sync_createCHECK
(
Script
)
VALUES (
@tsql
)
END;
FETCH NEXT FROM FKcursor INTO
@schema_name
, @table_name
, @constraint_name
, @referenced_object_name
, @constraint_object_id
, @is_disabled
, @is_not_for_replication
, @is_not_trusted
, @delete_referential_action
, @update_referential_action
, @referenced_schema_name;
END;
CLOSE FKcursor;
DEALLOCATE FKcursor;
--SELECT * FROM sync_DropFK
--SELECT * FROM sync_CreateFK
--SELECT * FROM sync_CreateCHECK
---------------------------------------------------------------------------
2.)
-----------------------------------------------------------------------------------------------------------------
----------------------------execute Drop FK Scripts --------------------------------------------------
DECLARE @scriptD NVARCHAR(4000)
DECLARE DropFKCursor CURSOR FOR
SELECT Script
FROM sync_dropFK WITH (NOLOCK)
OPEN DropFKCursor
FETCH NEXT FROM DropFKCursor
INTO @scriptD
WHILE @@FETCH_STATUS = 0
BEGIN
--PRINT @scriptD
EXEC (@scriptD)
FETCH NEXT FROM DropFKCursor
INTO @scriptD
END
CLOSE DropFKCursor
DEALLOCATE DropFKCursor
--------------------------------------------------------------------------------
3.)
------------------------------------------------------------------------------------------------------------------
----------------------------Truncate all tables in the database other than our staging tables --------------------
------------------------------------------------------------------------------------------------------------------
EXEC sp_MSforeachtable 'IF OBJECT_ID(''?'') NOT IN
(
ISNULL(OBJECT_ID(''dbo.sync_createCHECK''),0),
ISNULL(OBJECT_ID(''dbo.sync_createFK''),0),
ISNULL(OBJECT_ID(''dbo.sync_dropFK''),0)
)
BEGIN TRY
TRUNCATE TABLE ?
END TRY
BEGIN CATCH
PRINT ''Truncation failed on''+ ? +''
END CATCH;'
GO
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------
----------------------------execute Create FK Scripts and CHECK CONSTRAINT Scripts---------------
----------------------------tack me at the end of the ETL in a SQL task-------------------------
-------------------------------------------------------------------------------------------------
DECLARE @scriptC NVARCHAR(4000)
DECLARE CreateFKCursor CURSOR FOR
SELECT Script
FROM sync_createFK WITH (NOLOCK)
OPEN CreateFKCursor
FETCH NEXT FROM CreateFKCursor
INTO @scriptC
WHILE @@FETCH_STATUS = 0
BEGIN
--PRINT @scriptC
EXEC (@scriptC)
FETCH NEXT FROM CreateFKCursor
INTO @scriptC
END
CLOSE CreateFKCursor
DEALLOCATE CreateFKCursor
-------------------------------------------------------------------------------------------------
DECLARE @scriptCh NVARCHAR(4000)
DECLARE CreateCHECKCursor CURSOR FOR
SELECT Script
FROM sync_createCHECK WITH (NOLOCK)
OPEN CreateCHECKCursor
FETCH NEXT FROM CreateCHECKCursor
INTO @scriptCh
WHILE @@FETCH_STATUS = 0
BEGIN
--PRINT @scriptCh
EXEC (@scriptCh)
FETCH NEXT FROM CreateCHECKCursor
INTO @scriptCh
END
CLOSE CreateCHECKCursor
DEALLOCATE CreateCHECKCursor
WITH CHECK CHECK 几乎肯定是必需的!
在一些答案和评论中提出了这一点,但我觉得重新称之为重要.
使用以下命令重新启用约束(否WITH CHECK)将具有一些严重的缺点.
ALTER TABLE MyTable CHECK CONSTRAINT MyConstraint;
与检查| 没有检查
指定是否针对新添加或重新启用的FOREIGN KEY或CHECK约束验证表中的数据.如果未指定,则假定对于新约束使用WITH CHECK,并且对于重新启用的约束假定使用WITH NOCHECK.
如果您不想针对现有数据验证新的CHECK或FOREIGN KEY约束,请使用WITH NOCHECK.除极少数情况外,我们不建议这样做.将在所有后续数据更新中评估新约束.添加约束时由WITH NOCHECK抑制的任何约束违规可能会导致将来更新失败,如果他们使用不符合约束的数据更新行.
查询优化器不考虑使用NOCHECK定义的约束.在使用ALTER TABLE表WITH CHECK CHECK CONSTRAINT ALL重新启用这些约束之前,将忽略这些约束.
注意: WITH NOCHECK是重新启用约束的默认值.我不知道为什么......
在执行此命令期间,不会评估表中的现有数据 - 成功完成并不能保证表中的数据根据约束有效.
在下次更新无效记录期间,将评估约束并将失败 - 导致可能与实际更新无关的错误.
依赖于约束来确保数据有效的应用程序逻辑可能会失败.
查询优化器不会使用以这种方式启用的任何约束.
该sys.foreign_keys系统视图提供了一些可视化的问题.请注意,它同时包含is_disabled一个is_not_trusted列和一个列.is_disabled指示是否将针对约束验证将来的数据操作操作.is_not_trusted指示表中当前的所有数据是否已根据约束进行验证.
ALTER TABLE MyTable WITH CHECK CHECK CONSTRAINT MyConstraint;
您的约束是否值得信任？找出...
SELECT * FROM sys.foreign_keys WHERE is_not_trusted = 1;
找到约束
SELECT *
FROM sys.foreign_keys
WHERE referenced_object_id = object_id('TABLE_NAME')
执行此SQL生成的SQL
SELECT
'ALTER TABLE ' + OBJECT_SCHEMA_NAME(parent_object_id) +
'.[' + OBJECT_NAME(parent_object_id) +
'] DROP CONSTRAINT ' + name
FROM sys.foreign_keys
WHERE referenced_object_id = object_id('TABLE_NAME')
Safeway公司.
注意:添加了删除约束的解决方案,以便可以删除或修改表而不会出现任何约束错误.
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