JDBC Tutorial - JDBC Select Record

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The following code shows how to retrieve data from a database table.

It issues a select command and gets the result by reading the ResultSet interface.

Example

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

public class Main {
  static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
  static final String DB_URL = "jdbc:mysql://localhost/STUDENTS";

  static final String USER = "username";
  static final String PASS = "password";

  public static void main(String[] args) throws Exception {
    Connection conn = null;
    Statement stmt = null;

    Class.forName(JDBC_DRIVER);
    conn = DriverManager.getConnection(DB_URL, USER, PASS);
    System.out.println("Deleting database...");
    stmt = conn.createStatement();

    conn = DriverManager.getConnection(DB_URL, USER, PASS);

    stmt = conn.createStatement();
    String sql = "SELECT id, first, last, age FROM Person";
    ResultSet rs = stmt.executeQuery(sql);
    while (rs.next()) {
      // Retrieve by column name
      int id = rs.getInt("id");
      int age = rs.getInt("age");
      String first = rs.getString("firstName");
      String last = rs.getString("lastName");

      // Display values
      System.out.print("ID: " + id);
      System.out.print(", Age: " + age);
      System.out.print(", First: " + first);
      System.out.println(", Last: " + last);
    }
    rs.close();
    stmt.close();
    conn.close();
  }
}

Example PreparedStatement

The following code shows how to execute a select statement with PreparedStatement by using the Oracle JDBC driver.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
/*from   w  w w .j  a v a2 s  .c  o  m*/
public class Main {
  private static final String DB_DRIVER = "oracle.jdbc.driver.OracleDriver";
  private static final String DB_CONNECTION = "jdbc:oracle:thin:@localhost:1521:YourDatabase";
  private static final String DB_USER = "user";
  private static final String DB_PASSWORD = "password";

  public static void main(String[] argv) throws Exception {
    Connection dbConnection = null;
    PreparedStatement preparedStatement = null;
    Class.forName(DB_DRIVER);
    dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER,
        DB_PASSWORD);

    String selectSQL = "SELECT USER_ID, USERNAME FROM Person WHERE USER_ID = ?";
    preparedStatement = dbConnection.prepareStatement(selectSQL);
    preparedStatement.setInt(1, 1001);

    ResultSet rs = preparedStatement.executeQuery();

    while (rs.next()) {

      String userid = rs.getString("USER_ID");
      String username = rs.getString("USERNAME");

      System.out.println("userid : " + userid);
      System.out.println("username : " + username);

    }

    preparedStatement.close();
    dbConnection.close();

  }
}

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