How to prevent storing duplicate values

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dotpro2008 - 15 Feb 2008 00:17 GMT

In ASP.NET 2.0 project, I have added a dataset and have setup the datatable
and configured the datatableadapter (using the wizards).

In my code I can use the mytableadapter.insert method to insert a new record
in the table.

How do I check if the key column value being inserted this time already
exists and hence prompt the user the message ("userid already exists" or
"email address already exists")

Thanks,

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Misbah Arefin - 15 Feb 2008 22:05 GMT

You can use the DataTable.Select() method to search for the userid in the
datatable if it exists then show error message otherwise insert
another option would be to create a unique index on the userid column
DataTable.Columns["ColumnName"].Unique = true;

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Misbah Arefin

> In ASP.NET 2.0 project, I have added a dataset and have setup the datatable
> and configured the datatableadapter (using the wizards).
[quoted text clipped - 7 lines]
>
> Thanks,

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Misbah Arefin - 15 Feb 2008 22:32 GMT

sorry to RE: on my own post but if your original intent was that the dattable
is empty and you are inserting a new row and wanted to check it against the
db rows then you would have to execute some SP which would seach the db table
for that value and return a scalar value indicating if the data exists or not

Signature

Misbah Arefin

> You can use the DataTable.Select() method to search for the userid in the
> datatable if it exists then show error message otherwise insert
[quoted text clipped - 12 lines]
> >
> > Thanks,

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How to prevent storing duplicate values

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