Question

I am developing a two-tier java application that basically displays mySQL database results in a JTable in a GUI. The mySQL queries are typed in by the user in a textArea and then an ‘execute command’ button is pressed and the mySQL results corresponding to that command simply appear in the JTable.

The problem I am running into is when I try to type in a query such as “SELECT * FROM bikes WHERE COST=10000;” everything works as expected and results are returned. However, if I type in “select * from bikes where cost=10000;”, no results are returned and basically nothing happens, not even getting an error. I tried running ‘toUpperCase()’ on the query, which didn’t fix the problem.

I was wondering what might be causing this problem? I am aware that mySQL is not case sensitive, so it should work even if my SELECT is lower case…
The code below is a snippet of the area that might be causing the problem.

public void setQuery(String query) throws SQLException, IllegalStateException{
        if(!connectedToDatabase)
            throw new IllegalStateException("Not Connected to Database");


        String firstWord = query.substring(0, 6);
        if(firstWord.toUpperCase().equals("SELECT")){           
            resultSet = statement.executeQuery(query);
        }
        else if(firstWord.toUpperCase().equals("INSERT") || firstWord.toUpperCase().equals("DELETE") || firstWord.toUpperCase().equals("UPDATE")){
            statement2.executeUpdate(query);
        }

        metaData = resultSet.getMetaData();

        resultSet.last();
        numberOfRows = resultSet.getRow();
        fireTableStructureChanged();
    }

Answer 1

• Try using equalsIgnoreCase instead of straight equals.
• If you don’t know if the code is getting into an if block, try adding some logging into that block.
• Assuming it is getting into the block, the query is likely causing the problem.