实际上，你应该能够像暂时禁用其他约束一样禁用外键约束:

Alter table MyTable nocheck constraint FK_ForeignKeyConstraintName

只需确保在约束名称中列出的第一个表上禁用了约束。例如，如果我的外键约束是FK_LocationsEmployeesLocationIdEmployeeId，我想使用以下:

Alter table Locations nocheck constraint FK_LocationsEmployeesLocationIdEmployeeId

尽管违反这个约束会产生一个错误，这个错误不一定会将该表作为冲突的来源。

找到约束条件

SELECT * 
FROM sys.foreign_keys
WHERE referenced_object_id = object_id('TABLE_NAME')

执行由此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')

西夫韦。

注意:增加了删除约束的解决方案，这样可以删除或修改表而没有任何约束错误。

一个脚本来管理它们:这个脚本将截断和删除命令与sp_MSforeachtable结合在一起，这样您就可以避免删除和重新创建约束——只需指定需要删除而不是截断的表，为了便于度量，我还包含了一个额外的模式过滤器(在2008r2中测试)。

declare @schema nvarchar(max) = 'and Schema_Id=Schema_id(''Value'')'
declare @deletiontables nvarchar(max) = '(''TableA'',''TableB'')'
declare @truncateclause nvarchar(max) = @schema + ' and o.Name not in ' +  + @deletiontables;
declare @deleteclause nvarchar(max) = @schema + ' and o.Name in ' + @deletiontables;        

exec sp_MSforeachtable 'alter table ? nocheck constraint all', @whereand=@schema
exec sp_MSforeachtable 'truncate table ?', @whereand=@truncateclause
exec sp_MSforeachtable 'delete from ?', @whereand=@deleteclause
exec sp_MSforeachtable 'alter table ? with check check constraint all', @whereand=@schema

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

最好的选择是DROP和CREATE外键约束。

我在这篇文章中没有找到对我“原样”工作的例子，如果外键引用不同的模式，一个不会工作，如果外键引用多列，另一个也不会工作。这个脚本同时考虑多个模式和每个外键的多个列。

下面是生成“ADD CONSTRAINT”语句的脚本，对于多列，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

下面是生成“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

实际上，你应该能够像暂时禁用其他约束一样禁用外键约束:

Alter table MyTable nocheck constraint FK_ForeignKeyConstraintName

只需确保在约束名称中列出的第一个表上禁用了约束。例如，如果我的外键约束是FK_LocationsEmployeesLocationIdEmployeeId，我想使用以下:

Alter table Locations nocheck constraint FK_LocationsEmployeesLocationIdEmployeeId

尽管违反这个约束会产生一个错误，这个错误不一定会将该表作为冲突的来源。