error cannot find symbol in PreparedStatement

Question

why it error cant find symbol in

PreparedStatement ps = connection.prepareStatement(sql);
                           ^
variable connection

but variable connection has benn declaredlike this : *i input the correct username, password and url

try {
        Class.forName("org.postgresql.Driver");
}
catch (java.lang.ClassNotFoundException e) {
    System.out.println(e.getMessage());
}
try {
    String url = "jdbc:postgresql://stampy.db.elephantsql.com/";
    String username = "";
    String password = "";
    Connection connection = DriverManager.getConnection(url, username, password);
    List<AdvDetail> list = new ArrayList();
} catch(SQLException e) {
        System.out.println(e.getMessage());
}

I have import library

import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.PreparedStatement;
import java.sql.*;

import a1.kmita.com.model.Adv;
import a1.kmita.com.model.AdvDetail;
import a1.kmita.com.listener.ExceptionListener;
import a1.kmita.com.model.Response;

and the other spring libraries

here the code

try {
    String sql = "INSERT INTO advert (ad_title, ad_desc, ad_price, ad_image1,) VALUES (?, ?, ?, ?)"; /* this is the query */
    PreparedStatement ps =  connection.prepareStatement(sql); /* this is error */                
    ps.setString(1, product_name);
    ps.setString(2, product_desc);
    ps.setInt(3, product_price);
    ps.setString(4, image1);
    ps.executeUpdate();
    ps.close();         
} catch(SQLException e) {
    System.out.println(e.getMessage());
}

Possible duplicate of [What does a "Cannot find symbol" compilation error mean?](http://stackoverflow.com/questions/25706216/what-does-a-cannot-find-symbol-compilation-error-mean) — DontKnowMuchBut Getting Better, Mar 26 '17 at 16:36
I don't know if this could affect anything, but it seems like you have an extra comma after `ad_image1`. In your sql String — XXIV, Mar 26 '17 at 16:36
@javaguy: *ahem* `connection` **variable**. Objects aren't declared. — DontKnowMuchBut Getting Better, Mar 26 '17 at 16:39

Vinit Sarvade · Answer 1 · 2017-03-26T16:46:40.370

0

You have not created a connection object before using it. Check this sample:

Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection(DB_URL,USERNAME,PASS);

edited Mar 26 '17 at 16:46

answered Mar 26 '17 at 16:39

Vinit Sarvade

750
6
14

This can't be the problem as it won't cause a cannot find symbol compilation error but rather a NPE, a NullPointerException. – DontKnowMuchBut Getting Better Mar 26 '17 at 16:40
1

The poster has not declared the variable, thus the varibale cannot be found -.- (Importing the package alone is not enough) – Fabian N. Mar 26 '17 at 16:44

Fabian N. · Accepted Answer · 2017-03-26T17:32:13.117

0

connection is a varaiable, which must be initialized with your connection properties. Importing the package alone is not enough.

You could do it like so (for example for postgresql):

Connection connection = null;
try{
    Class.forName("org.postgresql.Driver");
    String connectionString = "jdbc:postgresql://" + dbhost + ":" + dbport + "/" + dbname;
    connection = DriverManager.getConnection(connectionString, dbuser, dbpassword)
}catch (Exception e){
    //...
}

Edit: The declaration of the variable must be before the try block, else the variable is in the scope of the try block. Loook at my example, how you can do this.

edited Mar 26 '17 at 17:32

answered Mar 26 '17 at 16:43

Fabian N.

1,221
10
18

i alredy did initialized but i dont write its code on question above, sorry – Al Pepa Indra Mar 26 '17 at 17:18
As in the comments said, look at this list http://stackoverflow.com/questions/25706216/what-does-a-cannot-find-symbol-compilation-error-mean and check, which point is true for you. I guess it is spelling (As you don't show us this part of the code, this is only a guess) You can post this part of the code and blank out Username/Password) – Fabian N. Mar 26 '17 at 17:26
sorry for not show the other part of code, but i already edit and add the other part of code. and thanks for the link you send – Al Pepa Indra Mar 26 '17 at 17:30

error cannot find symbol in PreparedStatement

2 Answers2