查找数据库中所有表中的字段包含特定值，之后修改特定值

declare @cloumns varchar(40)
declare @tablename varchar(40)
declare @str varchar(40)
declare @counts int
declare @sql nvarchar(2000)
declare @str2 nvarchar(2000)
declare MyCursor Cursor For
Select a.name as Columns, b.name as TableName from syscolumns a,sysobjects b,systypes c
where a.id = b.id
and b.type = 'U'
and a.xtype=c.xtype
and c.name like '%varchar%'
---数据库中的老值
set @str='a392ab5a-9972-46e2-8a32-4afe78ca1076'
---需要更新的新值
set @str2 = 'a392ab5a-9972-46e2-8a32-4afe78ca1076-00'
Open MyCursor
Fetch next From MyCursor Into @cloumns,@tablename
While(@@Fetch_Status = 0)
Begin
set @sql='select  @tmp_counts=count(*) from ' +@tablename+ ' where ' +@cloumns+' = ''' +@str+ ''''
execute sp_executesql  @sql,N'@tmp_counts int out',@counts out
if @counts>0
begin
---print '表名为:'+@tablename+',字段名为'+@cloumns
set @sql = 'update ' + @tablename + ' set ' + @cloumns + '=''' + @str2 + ''' where ' +@cloumns+' = ''' +@str+ ''''
execute sp_executesql  @sql
---print @sql
end
Fetch next From MyCursor Into @cloumns,@tablename
End
Close MyCursor
Deallocate MyCursor