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SQL statements in Java

Posted on 2004-08-26
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Last Modified: 2010-03-31
Hello.  I'm writing a test program that connects to my sample Northwood database that comes with SQL Server.  Here is the code, and I'll describe the error after:

import java.net.URL;
import java.sql.*;

class ODBC  
{
      public static Connection con;
      public static Statement stmt;
      public static String url = "jdbc:odbc:Northwind";
            
      public static void main (String args[])
      {
            try
            {
                  Driver d = (Driver)Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
                  Connection con = DriverManager.getConnection(url,
                        "sa", "!dbpass");
                  
                  String query = "select Password from Employees where LastName = 'Doe'";
                  ResultSet rs = stmt.executeQuery(query);
                  while(rs.next())
                  {
                        String s = rs.getString("password");
                        System.out.println(s);
                  }
            }
            catch(Exception e)
            {
                  e.printStackTrace();
            }
      }              
 }

I'm getting a NullPointerException at the line with ResultSet rs = stmt.executeQuery(query).  Any tips?

p.s.  on the line String s = rs.getString("password"), I'm pretty sure I can just put 0 instead of "password".  Is this correct if I'm just pulling one value?  
0
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Question by:ike2010
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11 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 11901861
Check the connection string
0
 
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Expert Comment

by:CEHJ
ID: 11901874
Doh - sorry - you haven't initialised the Statement
0
 
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Accepted Solution

by:
CEHJ earned 250 total points
ID: 11901891
stmt = con.createStatement();
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LVL 86

Expert Comment

by:CEHJ
ID: 11901900
You should also close the ResultSet and Statement
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 11901903
>>I'm pretty sure I can just put 0 instead of "password".  

If you're fairly sure there's no password, then just do ""
0
 

Expert Comment

by:dsj_shock
ID: 11901919
That is because you have not initialized the Statement stmt yet. Use the following code in the try..catch region:

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver").newInstance();
Connection con = DriverManager.getConnection(url, "sa", "!dbpass");
Statement stmt = con.createStatement(); // <--- this is the new line
...

By the way, 'Driver d = (Driver)' is not necessary when creating a new instance of the driver.

You cannot put 0 instead of the password, because the getConnection()-method does not accept an int as password, only a String.
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 11901968
>>That is because you have not initialized the Statement stmt yet

Please read the thread before posting - that was said five minutes earlier
0
 

Expert Comment

by:dsj_shock
ID: 11902005
Sry, it was not posted when I started typing :-)
0
 
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Expert Comment

by:CEHJ
ID: 11902033
OK :-)
0
 

Author Comment

by:ike2010
ID: 11902059
I can't believe I missed that.  Stupid me.  Thanks to both of you for your help.
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 11902133
8-)
0

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