Create Statement and set the ResultSet type: read only, scrollable : ResultSet Type « Database « Java Tutorial

1. Java Tutorial
2. Database
3. ResultSet Type

When creating a Statement object, you need to specify two arguments to the method createStatement().

The first argument indicates the type of a ResultSet object:

1. ResultSet.TYPE_FORWARD_ONLY: cursor may move only forward
2. ResultSet.TYPE_SCROLL_INSENSITIVE: scrollable but generally not sensitive to changes made by others
3. ResultSet.TYPE_SCROLL_SENSITIVE: scrollable and generally sensitive to changes made by others

The second argument:

1. ResultSet.CONCUR_READ_ONLY: the concurrency mode that may not be updated
2. ResultSet.CONCUR_UPDATABLE: the concurrency mode that may be updated

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Main {
  public static void main(String[] args) throws Exception {
    Connection conn = getConnection();
    Statement st = conn.createStatement(
        ResultSet.TYPE_SCROLL_SENSITIVE,
        ResultSet.CONCUR_READ_ONLY);

    st.executeUpdate("create table survey (id int,name varchar(30));");
    st.executeUpdate("insert into survey (id,name ) values (1,'nameValue')");
    st.executeUpdate("insert into survey (id,name ) values (2,null)");
    st.executeUpdate("insert into survey (id,name ) values (3,'Tom')");
    ResultSet rs = st.executeQuery("SELECT * FROM survey");


    // extract data from the ResultSet scroll from top
    while (rs.next()) {
        String id = rs.getString(1);
        String name = rs.getString(2);
        System.out.println("id=" + id + " name=" + name);
    }
    System.out.println("---------");

    // scroll from the bottom
    rs.afterLast();
    while (rs.previous()) {
        String id = rs.getString(1);
        String name = rs.getString(2);
        System.out.println("id=" + id + " name=" + name);
    }

    
    rs.close();
    st.close();
    conn.close();

  }

  private static Connection getConnection() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    String url = "jdbc:hsqldb:mem:data/tutorial";

    return DriverManager.getConnection(url, "sa", "");
  }
}

id=1 name=nameValue
id=2 name=null
id=3 name=Tom
---------
id=3 name=Tom
id=2 name=null
id=1 name=nameValue