CODEWITHSUNDEEP
javajdbcjavadb
TiOLUWA
TiOLUWA

Reputation: 225

Java database query statement returns null

I have a Java database set up in NetBeans 7, connected to it, but my query turns up null.

My database is named Questioneer, and the table is named QNTABLE, under the APP folder in the services tab.

I used the query 

query = "select QNNAME from QNTABLE"; // (QNNAME is a field name) with the statement: 

Statement st = dbConn.createStatement();
ResultSet rs = st.executeQuery(query);

with this, but st and rs turned up as null.

Upvotes: 1

Views: 2729

Answers (2)

Ricardo
Ricardo

Reputation: 12069

Check your query variable. Maybe you're using double ' instead of " or a single '.

Upvotes: 0

Jon Skeet
Jon Skeet

Reputation: 1499870

Your code won't compile, as Java uses " for string literals, not ''.

Your diagnostics are certainly off, as if st is null then the final line will throw a NullPointerException.

Basically, you should re-examine not just your code, but how you're approaching it. Work out whether you're really running the code you think you are, and how you're checking the values of variables.

If you have instance variables called st and rs and they're being hidden by local variables called st and rs, that could explain some of the confusion.

Upvotes: 3

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