我试图写一个脚本,将完全清空SQL Server数据库。这是我目前所拥有的:

USE [dbname]
GO
EXEC sp_msforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT all'
EXEC sp_msforeachtable 'DELETE ?'

当我在管理工作室运行它时,我得到:

命令执行成功。

但当我刷新表列表时,它们都还在那里。我做错了什么?


当前回答

我知道这是一篇老文章了,但我已经在大量的数据库上尝试了所有的答案,我发现它们有时都有效,但不是所有时间都适用于SQL Server的各种(我只能假设)怪癖。

最后我想到了这个。我在任何地方都测试过这个(一般来说),它是有效的(没有任何隐藏的存储过程)。

主要用于SQL Server 2014。(但我尝试过的大多数其他版本似乎也很好)。

我尝试过while循环和null等,游标和其他各种形式,但它们似乎总是在一些数据库上失败,而不是其他没有明显的原因。

获得一个计数并使用它进行迭代似乎总是适用于我测试的所有内容。

USE [****YOUR_DATABASE****]
GO

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

-- Drop all referential integrity constraints --
-- Drop all Primary Key constraints.          --

DECLARE @sql  NVARCHAR(296)
DECLARE @table_name VARCHAR(128)

DECLARE @constraint_name VARCHAR(128)
SET @constraint_name = ''

DECLARE @row_number INT

SELECT @row_number = Count(*) FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc1
LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc2 ON tc2.CONSTRAINT_NAME = rc1.CONSTRAINT_NAME

WHILE @row_number > 0
BEGIN
    BEGIN
        SELECT TOP 1 @table_name = tc2.TABLE_NAME, @constraint_name = rc1.CONSTRAINT_NAME FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS rc1
        LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc2 ON tc2.CONSTRAINT_NAME = rc1.CONSTRAINT_NAME
        AND rc1.CONSTRAINT_NAME > @constraint_name
        ORDER BY rc1.CONSTRAINT_NAME
        SELECT @sql = 'ALTER TABLE [dbo].[' + RTRIM(@table_name) +'] DROP CONSTRAINT [' + RTRIM(@constraint_name)+']'
        EXEC (@sql)
        PRINT 'Dropped Constraint: ' + @constraint_name + ' on ' + @table_name
        SET @row_number = @row_number - 1
    END
END
GO

-- Drop all tables --

DECLARE @sql  NVARCHAR(156)
DECLARE @name VARCHAR(128)
SET @name = ''

DECLARE @row_number INT

SELECT @row_number = Count(*) FROM sysobjects WHERE [type] = 'U' AND category = 0

WHILE @row_number > 0
BEGIN
    SELECT @name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 AND [name] > @name ORDER BY [name])
    SELECT @sql = 'DROP TABLE [dbo].[' + RTRIM(@name) +']'
    EXEC (@sql)
    PRINT 'Dropped Table: ' + @name
    SET @row_number = @row_number - 1
END
GO

其他回答

Azure SQL +表(带约束)的模式与dbo + ipv6_database_firewall_rules条件不同。

这是一个小扩展https://stackoverflow.com/a/43128914/4510954的答案。

DECLARE @sql NVARCHAR(2000)

WHILE(EXISTS(SELECT 1 from INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='FOREIGN KEY'))
BEGIN
    SELECT TOP 1 @sql=('ALTER TABLE ' + CONSTRAINT_SCHEMA + '.[' + TABLE_NAME + '] DROP CONSTRAINT [' + CONSTRAINT_NAME + ']')
    FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
    WHERE CONSTRAINT_TYPE = 'FOREIGN KEY'
    EXEC(@sql)
    PRINT @sql
END

WHILE(EXISTS(SELECT * from INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME != '__MigrationHistory' AND TABLE_NAME != 'database_firewall_rules' AND TABLE_NAME != 'ipv6_database_firewall_rules'))
BEGIN
    SELECT TOP 1 @sql=('DROP TABLE ' + CONSTRAINT_SCHEMA  + '.[' + TABLE_NAME + ']')
    FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS
    WHERE TABLE_NAME != '__MigrationHistory' AND TABLE_NAME != 'database_firewall_rules'
    EXEC(@sql)
    PRINT @sql
END

看来这个命令应该不带方巾

EXEC sp_msforeachtable 'drop table ?'

sp_msforeachtable在Azure SQL中不可用

对于Azure SQL:

此查询将删除外键约束

DECLARE @Name VARCHAR(200)
DECLARE @Constraint VARCHAR(300)
DECLARE @SQL VARCHAR(300)

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)

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 [dbo].[' + 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)
END
GO

这将从数据库中删除所有表

DECLARE @Name VARCHAR(200)
DECLARE @SQL VARCHAR(300)

SELECT @Name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 ORDER BY [name])

WHILE @Name IS NOT NULL
BEGIN
    SELECT @SQL = 'DROP TABLE [dbo].[' + RTRIM(@name) +']' /*here you can change schema if it is different from dbo*/
    EXEC (@SQL)
    PRINT 'Dropped Table: ' + @Name
    SELECT @Name = (SELECT TOP 1 [name] FROM sysobjects WHERE [type] = 'U' AND category = 0 AND [name] > @Name ORDER BY [name])
END
GO

你差不多说对了,可以用:

EXEC sp_msforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT all'
EXEC sp_msforeachtable 'DROP TABLE ?'

但是第二行你可能需要执行不止一次,直到你停止得到错误:

Could not drop object 'dbo.table' because it is referenced by a FOREIGN KEY constraint.

信息:

Command(s) completed successfully.

表示已成功删除所有表。

对于时态表来说,由于可能会有一些外键和例外,这有点复杂:

在表XXX上执行删除表操作失败,因为在系统版本的时态表上不支持该操作

你可以使用的是:

-- Disable constraints (foreign keys)
EXEC sp_MSForEachTable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
GO

-- Disable system versioning (temporial tables)
EXEC sp_MSForEachTable '
 IF OBJECTPROPERTY(object_id(''?''), ''TableTemporalType'') = 2
  ALTER TABLE ? SET (SYSTEM_VERSIONING = OFF)
'
GO

-- Removing tables
EXEC sp_MSForEachTable 'DROP TABLE ?'
GO