What's wrong with my code
im trying using database with my application, but i have this error :
[Microsoft][ODBC Driver Manager] Invalid descriptor index
The query is like this : SELECT * FROM User
Which User table has 3 columns (id,name,level)
my java code is like this :
public ResultSet readData(String query){
ResultSet rs =null;
try{
openConnection();
stmt = conn.createStatement();
rs = stmt.executeQuery(query);
System.out.println("DBM : " + rs.getString(0));
}catch(Exception e){
System.out.println("Error : \n" + e.getMessage());
}
return rs;
}
privatevoid openConnection(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
conn = DriverManager.getConnection("jdbc:odbc:dsn_officework",
"","");
}catch(Exception ex){
System.out.println(ex.getMessage());
}
}
when i try to do :
System.out.println("DBM : " + rs.getString(0));
it throw an exception.
im using microsoft access 2003. the Data Source Name is fine.
is there something wrong with my code?
sorry for my bad english. im not too fluent.
[1933 byte] By [
MyPermanaa] at [2007-11-27 11:21:38]
# 1
It appears your problem is here:
rs = stmt.executeQuery(query);
System.out.println("DBM : " + rs.getString(0));
You need this:
rs = stmt.executeQuery(query);
while(rs.next()){
System.out.println("DBM : " + rs.getString(0));
}
Also, your connection should use try/catch/finally block.
Here is an example. There are better examples on google:
Connection conn=null;
ResultSet rs=null;
Statement stmt=null;
try{
conn=datasource.getConnection();
rs = stmt.executeQuery(query);
while(rs.next()){
System.out.println("DBM : " + rs.getString("name of column"));
}
}catch(SQLException e){
e.printstacktrace();
} finally{
if(conn!=null)
conn.close();
}
# 2
This is my code :
import java.sql.*;
import javax.sql.*;
/**
* Class that handle database needs
* @author Permana
*/
public class DatabaseManager {
private Connection conn;
private Statement stmt;
private ResultSet rs = null;
/** Creates a new instance of DatabaseManager */
public DatabaseManager() {
conn = null;
stmt = null;
}
public Connection getConnection(){
return this.conn;
}
public Statement getStatement(){
return this.stmt;
}
private void openConnection(){
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
conn = DriverManager.getConnection("jdbc:odbc:dsn_officework",
"","");
}catch(Exception ex){
System.out.println(ex.getMessage());
}
}
public void closeConnection(){
try {
stmt.close();
conn.close();
if(rs != null){
rs.close();
}
} catch (SQLException ex) {
ex.printStackTrace();
}
}
/**
* Melakukan perintah query INSERT, UPDATE, dan DELETE.
* @param query perintah SQL yang akan dijalankan
* @return jumlah baris yang ditambah, diubah, atau dihapus.
*/
public int saveData(String query){
int val = -1;
try{
openConnection();
stmt = conn.createStatement();
val = stmt.executeUpdate(query);
}catch(SQLException e){
System.out.println("Error pada saveData, karena :\n" + e.getMessage());
}finally{
try{
conn.close();
stmt.close();
}catch(SQLException ex){
System.out.println("Error pada saveData, karena :\n" + ex.getMessage());
}
}
return val;
}
public ResultSet readData(String query){
try{
openConnection();
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_UPDATABLE);
rs = stmt.executeQuery(query);
System.out.println("DBM : " + rs.getString(0));
}catch(Exception e){
System.out.println("Error pada readData, karena: \n" + e.getMessage());
}
return rs;
}
}
Im trying to make a class that will be handle all the database needs. Such as insert user, update, edit.
this is the way i use this class :
DatabaseManager dbm = new DatabaseManager();
// do the read data method
ResultSet rs = null;
String query = "SELECT * FROM User WHERE id='" + id+ "' AND password='" + this.password + "'";
rs = dbm.readData(query);
if(rs.next() == false){
System.out.println("ResultSet Empty");
throw new Exception("No user");
}else{
while(rs.next()){
id = rs.getInt("id");
}
}
dbm.closeConnection();
i have close the database connection. May be the other have class that i can use to handle all the database needs?
But, i'll give a try first. Thanks george123.
# 3
I try this code and it work fine
try{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
Connection conn = DriverManager.getConnection("jdbc:odbc:dsn_officework");
Statement stat = conn.createStatement();
ResultSet rs = stat.executeQuery("SELECT * FROM User");
while(rs.next()){
System.out.println("isi data : " + rs.getString(2) + "\n");
}
}catch(Exception ex){
System.out.println("Error :" +ex.getMessage());
}
So there are somthing wrong with my DatabaseManager.java
Guess i have to write database code in the User Interface.
