SQL Query In Java + Oracle

Question

I'm really struggling to get this SQL into my head while using java.

My problem is: I want to use a variable in my sql Query, and i cant seem to get it working, it catches the correct value(i'm showing it on a label), But it doesnt show any records, yet, if i replace the variable for a '5', it shows me the correct record...

        try {
             Class.forName("oracle.jdbc.driver.OracleDriver");
            conn = MySqlConnect.ConnectDb();


           int idaca = Integer.parseInt(idhist.getText());
  String query1 = "SELECT t.nome, h.Valor_Atual, h.Valor_Antigo, a.nome
                      FROM  Tecnologias t, Historico h, Academista a 
                       WHERE h.Id_Academista = a.Id_Academista AND a.Id_Academista = "+idaca+" AND h.Id_Tecnologia = t.Id_Tecnologia
                        AND (h.Valor_Atual || h.Valor_Antigo  || t.nome)  LIKE '%" + ValToSearch + "%'";

            Statement st = conn.createStatement();
            ResultSet rs = st.executeQuery(query1);

            historico history;

            while (rs.next()) {
                history = new historico(rs.getString("Nome"), rs.getInt("Valor_Antigo"),
                        rs.getInt("Valor_Atual"), rs.getString("Nome"));
                historicoList.add(history);
            } //END WHILE
        } //END TRY
        catch (Exception e) {
            JOptionPane.showInputDialog(null, e);
        }//END CATCH

Thats my code so far... The ValToSearch is working fine, tho...

Thank you in advance! Cheers

The ValToSearch is working fine, tho - If your query works when you manually type '%5%', it means that ValToSearch is not working. However the issue might be elsewhere in your code, it's hard to tell with just two lines of code — BackSlash
– BackSlash, Commented Nov 22, 2018 at 11:41
Im having problems with "+idaca+", if i replace it with 5, it works fine.. :/ — Eduardo Fernandes
– Eduardo Fernandes, Commented Nov 22, 2018 at 11:42
please use some query builder eg stackoverflow.com/questions/5620985/… — bato3
– bato3, Commented Nov 22, 2018 at 11:42
@EduardoFernandes Try to print query1 by adding System.out.println("sql query --> "+query1); — Jacob
– Jacob, Commented Nov 22, 2018 at 11:48

Rafael Palomino · Accepted Answer · 2018-11-22 11:42:26Z

4

Put an space before AND h.Id_Tecnologia. That should solve your problem.

answered Nov 22, 2018 at 11:42

Rafael Palomino

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5 Comments

Thilo Over a year ago

The error message you get from the database would have probably pointed at that problem. Always look at error messages. Make sure your program prints them (not just try/catch/ignore). Make sure to include them in Stackoverflow questions.

Eduardo Fernandes Over a year ago

There is no error message, thats the problem, it doesnt return anything

Eduardo Fernandes Over a year ago

Edited answer, but still no results :/

bato3 Over a year ago

do you use error handling like this docs.oracle.com/javase/tutorial/jdbc/basics/sqlexception.html

Rafael Palomino Over a year ago

Follow @Jåcob advice: print the String query1 to see what do you send to BD. Maybe the variables are not well initialized... Pd: Pretty weird way to catch an exception. Usually you use println() or a logger system (log4j, slf4j, etc) to show it in console. Pd2: I suggest you a guide for debugging if you are using the Eclipse IDE. Understanding it will help you to find errors or at least to show us to locate your real problem How to debug

bato3 · Accepted Answer · 2018-11-22 11:48:22Z

0

You are not afraid that in ValToSearch you get something like ' OR 1 IN (DELETE * FROM Tecnologias )? Use parametr escaping or better some query builder

answered Nov 22, 2018 at 11:48

bato3

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