Segare una tabella con foreing key senza fare log (truncate dove non è possibile!)

@TableToTruncate VARCHAR(64)

AS

BEGIN

SET NOCOUNT ON

-- GLOBAL VARIABLES
DECLARE @i int
DECLARE @Debug bit
DECLARE @Recycle bit
DECLARE @Verbose bit
DECLARE @TableName varchar(80)
DECLARE @ColumnName varchar(80)
DECLARE @ReferencedTableName varchar(80)
DECLARE @ReferencedColumnName varchar(80)
DECLARE @ConstraintName varchar(250)

DECLARE @CreateStatement varchar(max)
DECLARE @DropStatement varchar(max)
DECLARE @TruncateStatement varchar(max)
DECLARE @CreateStatementTemp varchar(max)
DECLARE @DropStatementTemp varchar(max)
DECLARE @TruncateStatementTemp varchar(max)
DECLARE @Statement varchar(max)

-- 1 = Will not execute statements
SET @Debug = 0
-- 0 = Will not create or truncate storage table
-- 1 = Will create or truncate storage table
SET @Recycle = 0
-- 1 = Will print a message on every step
set @Verbose = 1

SET @i = 1
SET @CreateStatement = 'ALTER TABLE [dbo].[] WITH NOCHECK ADD CONSTRAINT [] FOREIGN KEY([]) REFERENCES [dbo].[] ([])'
SET @DropStatement = 'ALTER TABLE [dbo].[] DROP CONSTRAINT []'
SET @TruncateStatement = 'TRUNCATE TABLE []'

-- Drop Temporary tables

IF OBJECT_ID('tempdb..#FKs') IS NOT NULL
DROP TABLE #FKs

-- GET FKs
SELECT ROW_NUMBER() OVER (ORDER BY OBJECT_NAME(parent_object_id), clm1.name) as ID,
OBJECT_NAME(constraint_object_id) as ConstraintName,
OBJECT_NAME(parent_object_id) as TableName,
clm1.name as ColumnName,
OBJECT_NAME(referenced_object_id) as ReferencedTableName,
clm2.name as ReferencedColumnName
INTO #FKs
FROM sys.foreign_key_columns fk
JOIN sys.columns clm1
ON fk.parent_column_id = clm1.column_id
AND fk.parent_object_id = clm1.object_id
JOIN sys.columns clm2
ON fk.referenced_column_id = clm2.column_id
AND fk.referenced_object_id= clm2.object_id
--WHERE OBJECT_NAME(parent_object_id) not in ('//tables that you do not wont to be truncated')
WHERE OBJECT_NAME(referenced_object_id) = @TableToTruncate
ORDER BY OBJECT_NAME(parent_object_id)

-- Prepare Storage Table
IF Not EXISTS(SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'Internal_FK_Definition_Storage')
BEGIN
IF @Verbose = 1
PRINT '1. Creating Process Specific Tables...'

-- CREATE STORAGE TABLE IF IT DOES NOT EXISTS
CREATE TABLE [Internal_FK_Definition_Storage]
(
ID int not null identity(1,1) primary key,
FK_Name varchar(250) not null,
FK_CreationStatement varchar(max) not null,
FK_DestructionStatement varchar(max) not null,
Table_TruncationStatement varchar(max) not null
)
END
ELSE
BEGIN
IF @Recycle = 0
BEGIN
IF @Verbose = 1
PRINT '1. Truncating Process Specific Tables...'

-- TRUNCATE TABLE IF IT ALREADY EXISTS
TRUNCATE TABLE [Internal_FK_Definition_Storage]
END
ELSE
PRINT '1. Process specific table will be recycled from previous execution...'
END

IF @Recycle = 0
BEGIN

IF @Verbose = 1
PRINT '2. Backing up Foreign Key Definitions...'

-- Fetch and persist FKs
WHILE (@i <= (SELECT MAX(ID) FROM #FKs)) BEGIN SET @ConstraintName = (SELECT ConstraintName FROM #FKs WHERE ID = @i) SET @TableName = (SELECT TableName FROM #FKs WHERE ID = @i) SET @ColumnName = (SELECT ColumnName FROM #FKs WHERE ID = @i) SET @ReferencedTableName = (SELECT ReferencedTableName FROM #FKs WHERE ID = @i) SET @ReferencedColumnName = (SELECT ReferencedColumnName FROM #FKs WHERE ID = @i) SET @DropStatementTemp = REPLACE(REPLACE(@DropStatement,'',@TableName),'',@ConstraintName)
SET @CreateStatementTemp = REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(@CreateStatement,'',@TableName),'',@ColumnName),'',@ConstraintName),'',@ReferencedTableName),'',@ReferencedColumnName)
SET @TruncateStatementTemp = REPLACE(@TruncateStatement,'',@TableName)

INSERT INTO [Internal_FK_Definition_Storage]
SELECT @ConstraintName, @CreateStatementTemp, @DropStatementTemp, @TruncateStatementTemp

SET @i = @i + 1

IF @Verbose = 1
PRINT ' > Backing up [' + @ConstraintName + '] from [' + @TableName + ']'

END
END
ELSE
PRINT '2. Backup up was recycled from previous execution...'

IF @Verbose = 1
PRINT '3. Dropping Foreign Keys...'

-- DROP FOREING KEYS
SET @i = 1
WHILE (@i <= (SELECT MAX(ID) FROM [Internal_FK_Definition_Storage])) BEGIN SET @ConstraintName = (SELECT FK_Name FROM [Internal_FK_Definition_Storage] WHERE ID = @i) SET @Statement = (SELECT FK_DestructionStatement FROM [Internal_FK_Definition_Storage] WITH (NOLOCK) WHERE ID = @i) IF @Debug = 1 PRINT @Statement ELSE EXEC(@Statement) SET @i = @i + 1 IF @Verbose = 1 PRINT ' > Dropping [' + @ConstraintName + ']'

END

IF @Verbose = 1
PRINT '4. Truncating Tables...'

-- TRUNCATE TABLES
-- SzP: commented out as the tables to be truncated might also contain tables that has foreign keys
-- to resolve this the stored procedure should be called recursively, but I dont have the time to do it...
/*
SET @i = 1
WHILE (@i <= (SELECT MAX(ID) FROM [Internal_FK_Definition_Storage])) BEGIN SET @Statement = (SELECT Table_TruncationStatement FROM [Internal_FK_Definition_Storage] WHERE ID = @i) IF @Debug = 1 PRINT @Statement ELSE EXEC(@Statement) SET @i = @i + 1 IF @Verbose = 1 PRINT ' > ' + @Statement
END
*/

IF @Verbose = 1
PRINT ' > TRUNCATE TABLE [' + @TableToTruncate + ']'

IF @Debug = 1
PRINT 'TRUNCATE TABLE [' + @TableToTruncate + ']'
ELSE
EXEC('TRUNCATE TABLE [' + @TableToTruncate + ']')

IF @Verbose = 1
PRINT '5. Re-creating Foreign Keys...'

-- CREATE FOREING KEYS
SET @i = 1
WHILE (@i <= (SELECT MAX(ID) FROM [Internal_FK_Definition_Storage])) BEGIN SET @ConstraintName = (SELECT FK_Name FROM [Internal_FK_Definition_Storage] WHERE ID = @i) SET @Statement = (SELECT FK_CreationStatement FROM [Internal_FK_Definition_Storage] WHERE ID = @i) IF @Debug = 1 PRINT @Statement ELSE EXEC(@Statement) SET @i = @i + 1 IF @Verbose = 1 PRINT ' > Re-creating [' + @ConstraintName + ']'

END

IF @Verbose = 1
PRINT '6. Process Completed'