serverfejl eller kodefejl?

Mit spørgsmål er egentlig simpelt. Er følgende en server fejl eller kode fejl?

500 Internal Server Error
java.sql.SQLException: SQL string is not Query
    at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:189)
    at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:231)
    at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:294)
    at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2631)
    at oracle.jdbc.driver.OracleStatement.executeQuery(OracleStatement.java:777)
    at mypackage.DbConnection.executeQuery(DbConnection.java:55)
    at _tilmeld._jspService(tilmeld.jsp:24)
    [SRC:/tilmeld.jsp]
    at oracle.jsp.runtime.HttpJsp.service(HttpJsp.java:139)
    at oracle.jsp.runtimev2.JspPageTable.service(JspPageTable.java:349)
    at oracle.jsp.runtimev2.JspServlet.internalService(JspServlet.java:509)
    at oracle.jsp.runtimev2.JspServlet.service(JspServlet.java:413)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:65)
    at oracle.security.jazn.oc4j.JAZNFilter.doFilter(Unknown Source)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:604)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:317)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
    at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:192)
    at java.lang.Thread.run(Thread.java:534)



koden ser er følgende


  <%
    DbConnection connection = new DbConnection();
    connection = connection.hentInstans();
   
    String fornavn = request.getParameter("fornavn");
    String efternavn = request.getParameter("efternavn");
    String sportsgren = request.getParameter("sportsgren");
    String cprnummer = request.getParameter("cprnummer");
   
   
    if (request.getParameter("fornavn").equalsIgnoreCase("") || request.getParameter("efternavn").equalsIgnoreCase("") || request.getParameter("cprnummer").equalsIgnoreCase("") )
    {
    out.println("<h1>Alle felter skal udfyldes!</h1>");
    }else {
    String query = "INSERT INTO Medlem (Medlemid, Sportsgrenid,Fornavn,Efternavn,Cprnr) VALUES (medlemidnr.NEXTVAL,"+sportsgren+",'"+fornavn+"', '"+efternavn+"', '"+cprnummer+"');";
    System.out.println(query);
    connection.executeQuery(query) ; 
   
   
   
    out.print(request.getParameter("fornavn") + "er hermed blevet indmeldt i klubben!" );
    }

    %>


som i kan se udskrives query'en og den virker fint hvis jeg indsætter sætningen direkte i databasen.