Home Forums SQL Server 2008 T-SQL (SS2K8) How to delete all rows if one row meets a criteria RE: How to delete all rows if one row meets a criteria

  • mittensonmaui (10/22/2013)


    Hi all I am running a query where I check medical orders on an encounter there can be 1000's of orders and if one of them matches a specific criteria we delete all of them. The common thread hear is a CSN #. I am running a CTE and marking a flag column with a 1 if the criteria is hit and 0 otherwise.

    My question is how do I delete this record and the other orders with the same CSN? Can I us a recursive CTE, cross apply? Not sure where to go from here any help appreciated Mahalo, Brew

    You are looking for something like this (note my comments):

    -- let's say we wanted to delete all csn_numbers that have at least one some_value='xxx'

    DECLARE @your_table TABLE

    (xxx_id int identity primary key,

    csn_number int not null,

    some_value varchar(20) null)

    INSERT INTO @your_table VALUES

    (100,'fff'),(100, 'yyy'),(100,'xxx'),(140,'abc'),(150,'xxx'),

    (200,'zzz'),(200, 'abc'),(210,'xxx'),(240,'bbb'),(250,'abc');

    --Here's what's in there now

    SELECT * FROM @your_table;

    WITH kill_list AS

    (

    SELECT * FROM @your_table

    WHERE csn_number IN (

    SELECT csn_number

    FROM @your_table WHERE some_value='xxx' GROUP BY csn_number)

    )

    DELETE FROM kill_list;

    --Here's what's in there now

    SELECT * FROM @your_table

    The cool thing about this technique is that, in SSMS, you can highlight run your SELECT statement first to see what will be deleted.

    "I cant stress enough the importance of switching from a sequential files mindset to set-based thinking. After you make the switch, you can spend your time tuning and optimizing your queries instead of maintaining lengthy, poor-performing code."

    -- Itzik Ben-Gan 2001