使用 T-SQL 截断数据库中的所有表

Question

有没有一种方法可以在不使用 TSQL 语言中的 sp_MSForEachTable 的情况下截断数据库中的所有表？背景：不是我的电话，DBA公司政策不允许sp_MSForEachTable。

EXEC sp_MSForEachTable 'TRUNCATE TABLE ?'

想知道这是否是最有效的方法，还是其他可用的选择？

select 'truncate table ' + Table_Schema + '.' + Table_Name from INFORMATION_SCHEMA.tables where table_type = 'base table'

另一个网站建议这样做： https: //www.mssqltips.com/sqlservertip/3218/truncate-all-tables-in-a-sql-server-database/

 /* TRUNCATE ALL TABLES IN A DATABASE */
DECLARE @dropAndCreateConstraintsTable TABLE
        (
         DropStmt VARCHAR(MAX)
        ,CreateStmt VARCHAR(MAX)
        )
/* Gather information to drop and then recreate the current foreign key constraints  */
INSERT  @dropAndCreateConstraintsTable
        SELECT  DropStmt = 'ALTER TABLE [' + ForeignKeys.ForeignTableSchema
                + '].[' + ForeignKeys.ForeignTableName + '] DROP CONSTRAINT ['
                + ForeignKeys.ForeignKeyName + ']; '
               ,CreateStmt = 'ALTER TABLE [' + ForeignKeys.ForeignTableSchema
                + '].[' + ForeignKeys.ForeignTableName
                + '] WITH CHECK ADD CONSTRAINT [' + ForeignKeys.ForeignKeyName
                + '] FOREIGN KEY([' + ForeignKeys.ForeignTableColumn
                + ']) REFERENCES [' + SCHEMA_NAME(sys.objects.schema_id)
                + '].[' + sys.objects.[name] + ']([' + sys.columns.[name]
                + ']); '
        FROM    sys.objects
        INNER JOIN sys.columns
                ON ( sys.columns.[object_id] = sys.objects.[object_id] )
        INNER JOIN ( SELECT sys.foreign_keys.[name] AS ForeignKeyName
                           ,SCHEMA_NAME(sys.objects.schema_id) AS ForeignTableSchema
                           ,sys.objects.[name] AS ForeignTableName
                           ,sys.columns.[name] AS ForeignTableColumn
                           ,sys.foreign_keys.referenced_object_id AS referenced_object_id
                           ,sys.foreign_key_columns.referenced_column_id AS referenced_column_id
                     FROM   sys.foreign_keys
                     INNER JOIN sys.foreign_key_columns
                            ON ( sys.foreign_key_columns.constraint_object_id = sys.foreign_keys.[object_id] )
                     INNER JOIN sys.objects
                            ON ( sys.objects.[object_id] = sys.foreign_keys.parent_object_id )
                     INNER JOIN sys.columns
                            ON ( sys.columns.[object_id] = sys.objects.[object_id] )
                               AND ( sys.columns.column_id = sys.foreign_key_columns.parent_column_id )
                   ) ForeignKeys
                ON ( ForeignKeys.referenced_object_id = sys.objects.[object_id] )
                   AND ( ForeignKeys.referenced_column_id = sys.columns.column_id )
        WHERE   ( sys.objects.[type] = 'U' )
                AND ( sys.objects.[name] NOT IN ( 'sysdiagrams' ) )
/* SELECT * FROM @dropAndCreateConstraintsTable AS DACCT  --Test statement*/
DECLARE @DropStatement NVARCHAR(MAX)
DECLARE @RecreateStatement NVARCHAR(MAX)
/* Drop Constraints */
DECLARE Cur1 CURSOR READ_ONLY
FOR
        SELECT  DropStmt
        FROM    @dropAndCreateConstraintsTable
OPEN Cur1
FETCH NEXT FROM Cur1 INTO @DropStatement
WHILE @@FETCH_STATUS = 0
      BEGIN
            PRINT 'Executing ' + @DropStatement
            EXECUTE sp_executesql @DropStatement
            FETCH NEXT FROM Cur1 INTO @DropStatement
      END
CLOSE Cur1
DEALLOCATE Cur1
/* Truncate all tables in the database in the dbo schema */
DECLARE @DeleteTableStatement NVARCHAR(MAX)
DECLARE Cur2 CURSOR READ_ONLY
FOR
        SELECT  'TRUNCATE TABLE [dbo].[' + TABLE_NAME + ']'
        FROM    INFORMATION_SCHEMA.TABLES
        WHERE   TABLE_SCHEMA = 'dbo'
                AND TABLE_TYPE = 'BASE TABLE'
  /* Change your schema appropriately if you don't want to use dbo */
OPEN Cur2
FETCH NEXT FROM Cur2 INTO @DeleteTableStatement
WHILE @@FETCH_STATUS = 0
      BEGIN
            PRINT 'Executing ' + @DeleteTableStatement
            EXECUTE sp_executesql @DeleteTableStatement
            FETCH NEXT FROM Cur2 INTO @DeleteTableStatement
      END
CLOSE Cur2
DEALLOCATE Cur2
/* Recreate foreign key constraints  */
DECLARE Cur3 CURSOR READ_ONLY
FOR
        SELECT  CreateStmt
        FROM    @dropAndCreateConstraintsTable
OPEN Cur3
FETCH NEXT FROM Cur3 INTO @RecreateStatement
WHILE @@FETCH_STATUS = 0
      BEGIN
            PRINT 'Executing ' + @RecreateStatement
            EXECUTE sp_executesql @RecreateStatement
            FETCH NEXT FROM Cur3 INTO @RecreateStatement
      END
CLOSE Cur3
DEALLOCATE Cur3
GO   

这个答案使用，所以不能利用：sp_MSForEachTable

/sf/ask/10867251/

Answer 1

我不确定为什么您想要截断数据库中的所有表，但是有多种方法可以做到这一点。您可以使用游标循环遍历 sys.tables 或 INFORMATION_SCHEMA.TABLES：

DECLARE @SqlCmd NVARCHAR(MAX)

DECLARE C1 CURSOR FOR
    SELECT N'TRUNCATE TABLE ' + QUOTENAME(s.name) + '.' + QUOTENAME(t.name) + ';'
    FROM sys.tables t
    INNER JOIN sys.schemas s ON s.schema_id = t.schema_id
    WHERE t.[name] <> 'sysdiagrams' 
        AND t.is_ms_shipped = 0

OPEN C1

FETCH NEXT FROM C1 INTO @SqlCmd

WHILE @@FETCH_STATUS = 0
BEGIN
    PRINT @SqlCmd
    -- EXEC sp_executesql @SqlCmd

    FETCH NEXT FROM C1 INTO @SqlCmd
END

CLOSE C1
DEALLOCATE C1

或者您可以使用 COALESCE 方法生成组合字符串：

DECLARE @SqlCmd NVARCHAR(MAX)

SELECT @SqlCmd = COALESCE(@SqlCmd + CHAR(10), '') + N'TRUNCATE TABLE ' + QUOTENAME(s.name) + '.' + QUOTENAME(t.name) + ';'
FROM sys.tables t
INNER JOIN sys.schemas s ON s.schema_id = t.schema_id
WHERE t.[name] <> 'sysdiagrams' 
    AND t.is_ms_shipped = 0

PRINT @SqlCmd

在这些示例中，您可以复制打印的语句并运行它们，也可以使用sp_executesql直接执行命令。

正如George Palacios所强调的，该解决方案不处理外键。这里有一个生成命令来删除和重新创建外键的解决方案，该解决方案可以很好地工作。