What is the response of a Select SQL statement when the requested data is not in the Database?

Question

I have a problem with a program that just freezes when you enter a request that is not in the database.
I can't find anything on the net that deals with this sort of problem.
I would like to put the functionality of detecting the non existence of the data in the database and dealing with it without crashing the application.
I'm trying to implement a java program that accesses an MS Access database and retrieves the data. I use java.sql.* package and jdbc.
All the other functionalities work (retrieving and updating data) but I haven't been able to resolve this bug.

Answer 1

The statement returns the null set when there is no data. Some languages have more problem with this than others. In most cases where you do have a problem you have to check for an end of file condition before you try to use the data. If you try to read a null set you will definately throw an error.

-Dio

Answer 2

A select statement that retrieves zero rows is perfectly OK in Oracle... it should work in Access too though.

It should not cause a computer freeze. Are you sure it's a query that returns zero rows or is it a query that cannot end? If it's the former it may be an Access bug.

Alternatively use the 'select count' as outlined at the URL below to see if it's a 'zero records returned' query.

Answer 3

The statement returns the null set when there is no data.

but I think you should implement "java.oledb" for using ms access instead of "java.sql"

Answer 4

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Answer 5

it may have not instaleed properly or there might be some file missing in ur SQL package when u got it installed. the ans which appears is something like " string not found"