ResultSet interface

ResultSet represents a table of data, that represents the result of executing a query. A default ResultSet object is not updatable, means it represents a cursor which moves forward only (Reading row by row).

It is possible to use ResultSet object as updatable/scrollable.

Statement stmt = con.createStatement(

                                  ResultSet.TYPE_SCROLL_INSENSITIVE,

                                  ResultSet.CONCUR_UPDATABLE);

ResultSet rs = stmt.executeQuery("SELECT id, name FROM employee");

In the above statement, rs is updatable also. Will see about this in subsequent posts.

A ResultSet object is automatically closed when the Statement object that generated it is closed, re-executed, or used to retrieve the next result from a sequence of multiple results.

/* Step 1: Import sql package */
import java.sql.*;

public class SampleApp {
    
    /* Update username, password and driver details here */
    static Connection getConnection() throws ClassNotFoundException, SQLException{
         /* Step 2: Load Driver */
        System.out.println("Loading/Registering driver");  
       
        Class.forName("com.mysql.jdbc.Driver");
         
        /* Step 3: Open connection to database */
        System.out.println("Connecting to database");
        String url = "jdbc:mysql://localhost/world";
        String userName = "root";
        String pasword = "tiger";
        return DriverManager.getConnection(url, userName, pasword);
    }
    
    public static void main(String args[]) throws SQLException, ClassNotFoundException{      
        Connection conn = getConnection();
        conn.setAutoCommit(false);
          /* Create table employee */
        String query = "CREATE TABLE employee (id int, name varchar(30), PRIMARY KEY(id))";
        Statement stmt = conn.createStatement();
        stmt.execute(query);     
        
        /* Insert data to employee table */
        query = "INSERT INTO employee values(1, \"Krishna\")";
        stmt.execute(query);
        query = "INSERT INTO employee values(2, \"Arjun\")";
        stmt.execute(query);
        query = "INSERT INTO employee values(3, \"Joel\")";
        stmt.execute(query);
        
        System.out.println("Calling roll back operation");
        
        query = "SELECT * FROM employee";
        ResultSet rs = stmt.executeQuery(query);
        
        while(rs.next()){
            int id  = rs.getInt("id");
            String name = rs.getString("name");
            System.out.println(id +" " + name);
        }
        System.out.println("Dropping table employee");
        query = "DROP TABLE employee";
        stmt.execute(query);
        
    rs.close();
        stmt.close();
        conn.close();
    }
}

Output

Loading/Registering driver
Connecting to database
Calling roll back operation
1 Krishna
2 Arjun
3 Joel
Dropping table employee

Prevoius                                                 Next                                                 Home