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Problem with null values

Author

Topic

Pinto
Aged Yak Warrior

590 Posts

Posted - 2005-01-13 : 11:30:58

I have imported a large Access table into SQL Server. One of the fields is a bit field, but the Access table has a large number of nulls in this field so when I try to display the data in bound text boxes on my web page I am getting the error 'Cast from type 'DBNull' to type 'Boolean' is not valid for those records with null and not 1

How can I get round this other than running an update query on my sql table to replace the nulls with 0

I am using asp.net

jhermiz

3564 Posts

Posted - 2005-01-13 : 11:31:57

quote:
Originally posted by Pinto

I have imported a large Access table into SQL Server. One of the fields is a bit field, but the Access table has a large number of nulls in this field so when I try to display the data in bound text boxes on my web page I am getting the error 'Cast from type 'DBNull' to type 'Boolean' is not valid for those records with null and not 1

How can I get round this other than running an update query on my sql table to replace the nulls with 0

I am using asp.net

just write code to check if it is null ?

And handle the result appropriately...

Keeping the web experience alive -- [url]http://www.web-impulse.com[/url]

Pinto
Aged Yak Warrior

590 Posts

Posted - 2005-01-14 : 09:58:53

I fill a dataset and my textboxes are bound so they automatically fill. How do I then code to cope with the null ?

DustinMichaels
Constraint Violating Yak Guru

464 Posts

Posted - 2005-01-14 : 10:36:34

You can check to see if something is null by doing something like this.

I'm guessing your using VB.NET

If Convert.IsDbNull = record("Your Boolean Column") Then
Use a value of 0
Else
Use value from your record

Dustin Michaels

spirit1
Cybernetic Yak Master

11752 Posts

Posted - 2005-01-14 : 12:42:37

or if you can live with it then do in your sql

select coalesce(col1, '') ...
from ...

Go with the flow & have fun! Else fight the flow

JimL
SQL Slinging Yak Ranger

1537 Posts

Posted - 2005-01-14 : 14:28:52

Or use a SP and isnull to build your page.

Select Isnull(yourcolumn,0)
from yourtable

Jim
Users <> Logic

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