The last modifications of this post were around 2 years ago, some information may be outdated!
Summary
If you need to flush all tables in a database that might have data. This will remove all primary / foreign keys and then the data.
Code
/* 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