Sql 如何删除数据库中的所有默认约束？

我需要删除SQL Server 2008数据库中的所有默认约束。有人写过T-SQL脚本来实现这一点吗？注意，我只需要删除默认约束，而不是任何其他类型的约束。

我发布代码，因为我讨厌让你注册阅读答案的网站。这个代码不是我的…先备份你的数据库

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这段代码似乎也删除了数据库中的所有约束，当OP想要保留其他约束时，我希望没有人会简单地下载一个他们不理解的脚本并在他们的数据上运行它……我并没有给他一个最终的解决方案，只是给他一条到达那里的路径（给一个人一条鱼，他吃一天——教一个人钓鱼，他吃一辈子）…更改一行代码，你就可以放弃你想要的任何类型的约束。。。

USE MyDB

DECLARE @sSql            NVARCHAR(4000) SET @sSql = ''
DECLARE @sTypeDesc       sysname        SET @sTypeDesc = ''
DECLARE @sTableName      sysname        SET @sTableName = ''
DECLARE @sConstraintName sysname        SET @sConstraintName = ''

DECLARE cur CURSOR DYNAMIC FOR
   SELECT name,
          type_desc,
          OBJECT_NAME(parent_object_id)
     FROM sys.objects
    WHERE is_ms_shipped = 0
      AND type_desc LIKE '%_CONSTRAINT'
    ORDER BY type_desc, name

WHILE 1 = 1
BEGIN
   OPEN cur   
   FETCH FIRST FROM cur INTO @sConstraintName, @sTypeDesc, @sTableName

   IF @@FETCH_STATUS != 0
   BEGIN
      CLOSE cur
      BREAK
   END

   WHILE @@FETCH_STATUS = 0
   BEGIN
      BEGIN TRY
         SET @sSql = 'ALTER TABLE ' + QUOTENAME(@sTableName) + ' DROP CONSTRAINT ' + QUOTENAME(@sConstraintName)
         RAISERROR('%s', 10, 1, @sSql) WITH NOWAIT   
         EXEC sp_executesql @sSql
      END TRY
      BEGIN CATCH
         DECLARE @ENumber      INT            SET @ENumber      = ISNULL(ERROR_NUMBER(),          -1)
         DECLARE @ESeverity    INT            SET @ESeverity    = ISNULL(ERROR_SEVERITY(),        -1)
         DECLARE @EState       INT            SET @EState       = ISNULL(ERROR_STATE(),            0) IF @EState = 0 SET @EState = 42
         DECLARE @EProcedure   NVARCHAR(126)  SET @EProcedure   = ISNULL(ERROR_PROCEDURE(), N'{N/A}')
         DECLARE @ELine        INT            SET @ELine        = ISNULL(ERROR_LINE(),            -1)
         DECLARE @EMessageRecv NVARCHAR(2048) SET @EMessageRecv = ISNULL(ERROR_MESSAGE(),        N'')
         DECLARE @EMessageSent NVARCHAR(440)  SET @EMessageSent = N''

         IF ERROR_PROCEDURE() IS NOT NULL   SET @EMessageSent = N'Error %d, Level %d, State %d, Procedure %s, Line %d, Message: '
         SET @EMessageSent = @EMessageSent + ERROR_MESSAGE()
         RAISERROR(@EMessageSent, 10 /* @ESeverity */ , @EState, @ENumber, @ESeverity, @EState, @EProcedure, @ELine) WITH LOG
      END CATCH

      FETCH NEXT FROM cur INTO @sConstraintName, @sTypeDesc, @sTableName
   END

   CLOSE cur
END

DEALLOCATE cur
GO

DECLARE @QueryText VARCHAR(MAX)
DECLARE CursorQuery CURSOR FOR

-- get all tables and build dynamic sql
SELECT 

'ALTER TABLE ' + '[' + s.[NAME] + '].[' + t.name + '] DROP CONSTRAINT ['+ c.name + ']'

FROM sys.objects c, sys.objects t, sys.schemas s

WHERE c.type IN ('C', 'F', 'PK', 'UQ', 'D')
        AND c.parent_object_id=t.object_id AND t.type='U' AND t.SCHEMA_ID = s.schema_id
ORDER BY c.type




BEGIN TRY

OPEN CursorQuery

FETCH NEXT FROM CursorQuery INTO @QueryText

WHILE (@@FETCH_STATUS = 0) BEGIN

 PRINT @QueryText 
 EXEC (@QueryText)
 FETCH NEXT FROM CursorQuery INTO @QueryText

END

CLOSE CursorQuery
DEALLOCATE CursorQuery


END TRY



-- ERROR Messaging
BEGIN CATCH

SELECT 
            @QueryText as 'ErrorQuery'
            , ErrorLine = ERROR_LINE()
            ,ErrorNumber = ERROR_NUMBER()
            ,ErrorSeverity = ERROR_SEVERITY()
            ,ErrorState = ERROR_STATE()
            ,ErrorMessage = ERROR_MESSAGE()
            ,ErrorStoredProcedure = ERROR_PROCEDURE()

END CATCH

SET NOCOUNT ON
DECLARE @dropstatements TABLE(Script VARCHAR(MAX))
DECLARE @script VARCHAR(MAX)

INSERT INTO @dropstatements
    (Script)
SELECT
    'ALTER TABLE dbo.' + OBJECT_NAME(parent_object_id) + 
    ' DROP CONSTRAINT ' + Name
FROM
    sys.default_constraints

WHILE EXISTS(SELECT 1 FROM @dropstatements)
BEGIN
    SELECT TOP 1 @script = Script FROM @dropstatements ORDER BY Script
    DELETE @dropstatements WHERE Script = @script
    PRINT @script
    EXEC (@script)
END