query is not getting executed

[Hrishikesh Maluskar]

can anyone tell me why the following query is not getting executed..i am using struts2 and MYSQL

  stmt=con.createStatement();
      rst=stmt.executeQuery("SELECT CONCAT (F_NAME ,' ' ,L_NAME) AS NAME,ADDR,DESCR,PEOPLE_ALLOWED,RENT,ID FROM WEBDB.FLAT_DTLS WHERE DEL_FLG='N' AND ID='"+request.getParameter("flatID")+"' ");
        

[Vijitha Kumara]

What is the issue you are having? Any exception.. ?

[David O'Meara]

how can you be sure that it is not being executed, as opposed to not returning any results?
Have you tried outputting the query and running it directly against the database?
as an outside chance: You're not using the Jdbc-ODBC bridge are you?

[Hrishikesh Maluskar]

the query runs directly in database.

in java it gives the following exception

java.sql.SQLException: Before start of result set
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)

my code is as follows

 
try{
      stmt=con.createStatement();
      rst=stmt.executeQuery("SELECT * FROM WEBDB.FLAT_DTLS; ");
      
      rst.next(); 
       	 System.out.println("*****************************ans88="+rst.getString(0));
    	 System.out.println("*****************************ans99="+rst.getString(1));
       }catch(Exception ex){
    	ex.printStackTrace();

[David O'Meara]

You can only get data if there is something to get

if(rst.next())
{
// found something
          System.out.println("*****************************ans88="+rst.getString(0));  
          System.out.println("*****************************ans99="+rst.getString(1));  
}
else
{
          System.out.println("Result was empty");
}

[Hrishikesh Maluskar]

there are two records in the database , which should be displayed. I feel that that the query is not getting executed at all.

[Jan Cumps]

Hi.
Your code is not going to fetch two records from the database. Calling getString(0) and getString(1) is not the mechanism to retrieve two rows.
You should loop the resultset using while(rst.next()) {...}

Try to find out when (at which line in your source) the java.sql.SQLException is thrown, and why.


Regards, Jan

[Hrishikesh Maluskar]

java.sql.SQLException: Column Index out of range, 0 < 1.
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)

i am getting the above exception after writing this code.

   
 try{
      stmt=con.createStatement();
      rst=stmt.executeQuery("SELECT * FROM WEBDB.FLAT_DTLS; ");
      
      if(rst.next())   
      {   
          System.out.println("*****************************ans88="+rst.getString(0));     
          System.out.println("*****************************ans99="+rst.getString(1));     
      }   
      else  
      {   
           System.out.println("Result was empty");   
       }  

       }catch(Exception ex){
    	ex.printStackTrace();
   	 }

[Fatih Keles]

As in most database also jdbc drivers start counting from 1 not 0.

it is stated in exception :

java.sql.SQLException: Column Index out of range, 0 < 1.

Regards,

Fatih.

[Neel Bera]

Hi,

I tried a program with database connection and tried retrieving values from DB. The following is the code inside while loop after successfully querying the DB

while(r.next())
        {
       String n=r.getString(1);
System.out.println("name"+ n);
}

I just stored the value in a String object "n". Then displayed the object "n".

also when i tried

System.out.println("name"+r.getString(1));

then I am getting a SQLException :
[Microsoft][ODBC SQL Server Driver]Invalid Descriptor Index


I am not sure if this is the solution to the prob, but you can give it a try.Also, if you are getting the correct solution please do post it.

Thank you.
Neel (Newbie)

[Hrishikesh Maluskar]

Thanks everybody this problem is solved..i had written rst.getString(0) , changing it to rst.getString(1) worked.