I'm trying to write a script that will completely empty a SQL Server database. This is what I have so far:
USE [dbname]
GO
EXEC sp_msforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT all'
EXEC sp_msforeachtable 'DELETE ?'
When I run it in the Management Studio, I get:
Command(s) completed successfully.
but when I refresh the table list, they are all still there. What am I doing wrong?
This question is related to
sql-server
sql-server-2008
ssms
sp-msforeachtable
/* Drop all Primary Key constraints */
DECLARE @name VARCHAR(128)
DECLARE @constraint VARCHAR(254)
DECLARE @SQL VARCHAR(254)
SELECT @name = (SELECT TOP 1 TABLE_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY 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 = 'PRIMARY 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 PK Constraint: ' + @constraint + ' on ' + @name
SELECT @constraint = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE constraint_catalog=DB_NAME() AND CONSTRAINT_TYPE = 'PRIMARY 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 = 'PRIMARY KEY' ORDER BY TABLE_NAME)
END
GO
/* Drop all tables */
DECLARE @name VARCHAR(128)
DECLARE @SQL VARCHAR(254)
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) +']'
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
You can also delete all tables from database using only MSSMS UI tools (without using SQL script). Sometimes this way can be more comfortable (especially if it is performed occasionally)
I do this step by step as follows:
Spot on!!
You can use below query to remove all the tables from database
EXEC sp_MSforeachtable @command1 = "DROP TABLE ?"
Happy coding !
For me, the easiest way:
--First delete all constraints
DECLARE @sql NVARCHAR(MAX);
SET @sql = N'';
SELECT @sql = @sql + N'
ALTER TABLE ' + QUOTENAME(s.name) + N'.'
+ QUOTENAME(t.name) + N' DROP CONSTRAINT '
+ QUOTENAME(c.name) + ';'
FROM sys.objects AS c
INNER JOIN sys.tables AS t
ON c.parent_object_id = t.[object_id]
INNER JOIN sys.schemas AS s
ON t.[schema_id] = s.[schema_id]
WHERE c.[type] IN ('D','C','F','PK','UQ')
ORDER BY c.[type];
EXEC sys.sp_executesql @sql;
-- Then drop all tables
exec sp_MSforeachtable 'DROP TABLE ?'
You are almost right, use instead:
EXEC sp_msforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT all'
EXEC sp_msforeachtable 'DROP TABLE ?'
but second line you might need to execute more then once until you stop getting error:
Could not drop object 'dbo.table' because it is referenced by a FOREIGN KEY constraint.
Message:
Command(s) completed successfully.
means that all table were successfully deleted.
The accepted answer doesn't support Azure. It uses an undocumented stored procedure "sp_MSforeachtable". If you get an "azure could not find stored procedure 'sp_msforeachtable" error when running or simply want to avoid relying on undocumented features (which can be removed or have their functionality changed at any point) then try the below.
This version ignores the entity framework migration history table "__MigrationHistory" and the "database_firewall_rules" which is an Azure table you will not have permission to delete.
Lightly tested on Azure. Do check to make this this has no undesired effects on your environment.
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 ' + TABLE_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'))
BEGIN
SELECT TOP 1 @sql=('DROP TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + ']')
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME != '__MigrationHistory' AND TABLE_NAME != 'database_firewall_rules'
EXEC(@sql)
PRINT @sql
END
Taken from:
https://edspencer.me.uk/2013/02/25/drop-all-tables-in-a-sql-server-database-azure-friendly/
http://www.sqlservercentral.com/blogs/sqlservertips/2011/10/11/remove-all-foreign-keys/
For Temporal Tables it is a bit more complicated due to the fact there may be some foreign keys and also exception:
Drop table operation failed on table XXX because it is not a supported operation on system-versioned temporal tables
What you can use is:
-- 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
In SSMS:
Now, this will drop everything, including the database. Make sure to remove the code for the items you don't want dropped. Alternatively, in the "Choose Objects" section, instead of selecting to script entire database just select the items you want to remove.
delete
is used for deleting rows from a table. You should use drop table
instead.
EXEC sp_msforeachtable 'drop table [?]'
How about dropping the entire database and then creating it again? This works for me.
DROP DATABASE mydb;
CREATE DATABASE mydb;
Short and sweet:
USE YOUR_DATABASE_NAME
-- Disable all referential integrity constraints
EXEC sp_MSforeachtable 'ALTER TABLE ? NOCHECK CONSTRAINT ALL'
GO
-- Drop all PKs and FKs
declare @sql nvarchar(max)
SELECT @sql = STUFF((SELECT '; ' + 'ALTER TABLE ' + Table_Name +' drop constraint ' + Constraint_Name from Information_Schema.CONSTRAINT_TABLE_USAGE ORDER BY Constraint_Name FOR XML PATH('')),1,1,'')
EXECUTE (@sql)
GO
-- Drop all tables
EXEC sp_MSforeachtable 'DROP TABLE ?'
GO
I know this is an old post now but I have tried all the answers on here on a multitude of databases and I have found they all work sometimes but not all of the time for various (I can only assume) quirks of SQL Server.
Eventually I came up with this. I have tested this everywhere (generally speaking) I can and it works (without any hidden store procedures).
For note mostly on SQL Server 2014. (but most of the other versions I tried it also seems to worked fine).
I have tried while loops and nulls etc etc, cursors and various other forms but they always seem to fail on some databases but not others for no obvious reason.
Getting a count and using that to iterate always seems to work on everything Ive tested.
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
Seems the command should be without the square blanket
EXEC sp_msforeachtable 'drop table ?'
The fasted way is:
Source: Stackoverflow.com