INSERT before checking duplicate values

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Guest

Hi

I am inserting 2 text values from user input. I wanted ot check if there is
any duplicate text value before I insert into columns...which is best way to
avoid duplicate valies....constraints or check in INSERT statement.....any
idea any pointes

thanks n advace

SAgar
 
Select Count(*) FROM tableName WHERE yourColumnName='" & txtUserInput & "';"

Anything greater than 0 means its already in the set
 
Hi

I am inserting 2 text values from user input. I wanted ot check if there is
any duplicate text value before I insert into columns...which is best way to
avoid duplicate valies....constraints or check in INSERT statement.....any
idea any pointes

thanks n advace

SAgar
Click to expand...

If the value in a table should be unique, there should be a constraint set on
it. The reasoning behind this is you may want to access the table from another
application at a later time. If you depend on code in the application to
enforce uniqueness, you or another developer may forget to code the test for
unique value insertion and update.

If you are using DataAdapters/DataSets to access the table you can set the
DataColumn's Unique property to true and save a round trip to the DB when
testing the value for uniqueness.

Good luck with your project,

Otis Mukinfus
http://www.arltex.com
http://www.tomchilders.com
 
Thanks...

Actually I am getting my 2 columns from WebServices and then add these to
Datagrud column during runtime.

MY requirement was to get from webservice then add to list but also store
locally these columns in table....while doing insert I want to check if data
is already there or not.....if its there I dont want to do any isert else I
want to insert.

How do I implement this? in ASP.Net using C#??

even if i do a check before I do insert is okk...

thx in advance

Regsd
Sagar
 
Thanks...

Actually I am getting my 2 columns from WebServices and then add these to
Datagrud column during runtime.

MY requirement was to get from webservice then add to list but also store
locally these columns in table....while doing insert I want to check if data
is already there or not.....if its there I dont want to do any isert else I
want to insert.

How do I implement this? in ASP.Net using C#??

even if i do a check before I do insert is okk...

thx in advance

Regsd
Sagar
Click to expand...
[snip]
I understood your original post, but I don't think you understood my answer to
your question. I simply told you what some of your options are. Now you must
decide how you will do it. You may have to do some research to determine what
suits your situation best.

If you feel you should do this the way you describe, then you should follow
OHM's good and valid advice. There is no rule against placing unique
constraints on two columns in a table (or more). Nor is there a rule against
doing a check before the insert.

Good luck with your project,

Otis Mukinfus
http://www.arltex.com
http://www.tomchilders.com
 
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