How do I avoide "Conversion from type 'DBNull' to type 'Double' is not valid." when there is no values in the database?

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How do I avoide "Conversion from type 'DBNull' to type 'Double' is not valid." when there is no values in the database? I am trying to add the perticular data field using
SQl select sum (field) from tablename where condition .
but getting the error mentioned above.

Posted 27-Feb-14 22:23pm

Ni!E$H_WAGH

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Richard MacCutchan 28-Feb-14 4:34am

You need to exclude records containing DBNull.

2 solutions

Solution 3

You can use Convert.IsDBNull Method[^].

Quote:
Returns an indication whether the specified object is of type DBNull.

Posted 27-Feb-14 22:45pm

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ)

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hypermellow · Accepted Answer · 2014-02-27T22:38:00

Solution 1

Depending on the type of database your querying, you could modify your query to replace any null results with 0.
... something like:

SQL

select ISNULL(sum(field),0) from tablename

Posted 27-Feb-14 22:38pm

hypermellow

Comments

Ni!E$H_WAGH 28-Feb-14 4:55am

Thank you very much .