Question

I have a repeater with about 100 rows, and 4 columns in each row. something like this table:

Username        HasIpod        HasGymMembership        HasCar
``````````````````````````````````````````````````````````````
User1            chcekbox        checkbox               checkbox
User2            chcekbox        checkbox               checkbox
User3            chcekbox        checkbox               checkbox
User4            chcekbox        checkbox               checkbox

well, you get the idea.

The admin can tick/untick any box anytime and click on a “Save” button at the end of page and thats when I need to update the database. I need to add a row in one of the table if a certain checkbox is checked, delete it if its unchecked.

I can just loop through the repeater and VERY EASILY do it with each row. but my concern is that, at the worst case, this will use about 100 rows X 3 = 300 database accesses. Thats bad right?

I thought of concatenating all values into a form of csv.. something like:

user1id,1,0,1;user1id,0,1,1

just a list of userid, its values separated with , and the next user’s values separated with ; and in the database I can just use a split function and a bunch of while loop and update accordingly.

but It just doesnt satisfy me for some reason. Is there a better way to deal with a such a situation? I am sure this is not a unique case, what do you guys do in a scenario? any insight about being a super fast “ninja” in this (with as little db access as possible) would be great.

thanks.

Answer 1

instead of csv you can use xml, like this:

DECLARE @DocHandle int
DECLARE @XmlDocument nvarchar(1000)
SET @XmlDocument = N'<ROOT>
<User Username="user1" HasIpod="1" HasGymMembership="1" HasCar="0" />
<User Username="user2" HasIpod="1" HasGymMembership="0" HasCar="1" />
<User Username="user3" HasIpod="0" HasGymMembership="1" HasCar="0" />
<User Username="user4" HasIpod="0" HasGymMembership="0" HasCar="1" />
</ROOT>'

EXEC sp_xml_preparedocument @DocHandle OUTPUT, @XmlDocument

SELECT *
FROM OPENXML (@DocHandle, '/ROOT/User',1)
      WITH (Username  varchar(100),
            HasIpod bit,
            HasGymMembership bit,
            HasCar bit)

/* ... update your tables here ... */

EXEC sp_xml_removedocument @DocHandle

UPDATE:
another way, assuming you use dirty state

DECLARE @DocHandle int
DECLARE @XmlDocument nvarchar(1000)
SET @XmlDocument = N'<root>
    <added>
        <ipod userID="1" />
        <ipod userID="2" />
        <gym userID="1" />
        <gym userID="3" />
        <car userID="2" />
        <car userID="4" />
    </added>
    <removed>
        <ipod userID="3" />
        <ipod userID="5" />
        <gym userID="4" />
        <gym userID="5" />
        <car userID="1" />
        <car userID="3" />
    </removed>
</root>'

EXEC sp_xml_preparedocument @DocHandle OUTPUT, @XmlDocument

insert into HasIPodTable SELECT * FROM OPENXML (@DocHandle, '/root/added/ipod',1) WITH (userID  int)
delete HasIPodTable where userID in (SELECT * FROM OPENXML (@DocHandle, '/root/removed/ipod',1) WITH (userID  int))

/* and the same for the others ... */

EXEC sp_xml_removedocument @DocHandle

that’s of course assuming you have 3 tables (ipod, gym, car). if not, then just update the Users table