The ALTER TABLE statement conflicted with the FOREIGN KEY constraint

ADVANCED VERSION WITH GENERATING THE RIGHT DELETE STATEMENTS

BEGIN

-- The ALTER TABLE statement conflicted with the FOREIGN KEY constraint "FK__". The conflict occurred in database "", table "", column ''.

-- THIS SCRIPT DOESNT EXECUTE DELETE STATEMENTS IT ONLY GENERATES THE SQL STATEMENTS

declare @Subtable as nvarchar(100), @roottable as nvarchar(100),  @idColumn as nvarchar(100)

set @Subtable=''

set @Roottable=''

set @idColumn=''

declare @SQLStatement as nvarchar(MAX) , @SQLStatement1 as nvarchar(MAX) ,@SQLStatement2 as nvarchar(MAX) ,@SQLStatement3 as nvarchar(MAX) ,

 @orderstat as nvarchar(MAX) ,  @wherestat as nvarchar(MAX)

SET @orderstat = ' ORDER BY ' + @idColumn

SET @SQLStatement = 'SELECT TOP 1 @ItemId = ' + @idColumn + ' FROM ' + @Subtable + ' as st ' + ' where not exists(select *  from ' + @Roottable + ' as rt where st.' + @idColumn + '=rt.' + @idColumn + ')and ' + @idColumn + ' is not null'

SET @SQLStatement2 = 'SELECT TOP 1 ' + @idColumn + ' FROM ' + @Subtable + ' as st ' + ' where not exists(select *  from ' + @Roottable + ' as rt where st.' + @idColumn + '=rt.' + @idColumn + ')and ' + @idColumn + ' is not null'

SET @SQLStatement3 = ' '' DELETE FROM ' + @Subtable + ' WHERE ' + @idColumn + '= '' + CONVERT(NVARCHAR(10),@ItemId) '

SET @SQLStatement1 = '

BEGIN

Declare @ItemId bigint

 ' + @SQLStatement + @orderstat + '

 PRINT ' + @SQLStatement3 + '

  WHILE @ItemId is not null 

  BEGIN

     if exists (' + @SQLStatement2 + '   AND   ' + @idColumn + '>@ItemId '+ @orderstat + ')

                  begin                                                       

                        ' + @SQLStatement + '  and ' + @idColumn + '>@ItemId  '+ @orderstat + '

                        PRINT ' + @SQLStatement3 + '

                  end

                  else

                  begin

                        set @ItemId=null

                  end

  END

END' 

exec sp_executesql @SQLStatement1

END