JDBC及简单抄作连接数据库源码

来源：互联网发布：如何做好网络招聘编辑：程序博客网时间：2024/06/08 05:20

package com;

//import oracle.jdbc.driver.OracleDriver;
import java.sql.*;

public class Database {
private Connection conn = null;
private Statement stmt = null;
private ResultSet rs = null;
public Database() {
    try {
//      Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
//      String url = "jdbc:oracle:thin:@localhost:1521:test"; //orcl为数据库的SID

Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
String url ="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=test"; //sqlserver为数据库的SID

// String user = "system";
// String password = "test";orcl为数据库的SID

      String user = "sa";
      String password = "";
      conn = DriverManager.getConnection(url, user, password);
      System.out.println("2000 is connected!");

    }
    catch (ClassNotFoundException ex) {
    }
    catch (IllegalAccessException ex) {
    }
    catch (InstantiationException ex) {
    }
    catch (SQLException e) {
      e.printStackTrace();
    }
    ;

}

//query
public ResultSet getQuery() {
    String sql = "SELECT * FROM empl";
    try {
      stmt = conn.createStatement();
      rs = stmt.executeQuery(sql);
      return rs;
    }
    catch (SQLException ex) {
      ex.printStackTrace();
//      System.out.println(ex.getMessage());
      return null;
    }

}

//update
public void getUpdate() {
    String sql = "update scott.dept set dname =" + "'hh'" + " where loc =" +
        "'DALLAS'";
    System.out.println(sql);
    try {
      stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
                                  ResultSet.CONCUR_UPDATABLE);
      int i = stmt.executeUpdate(sql);
      if (i > 0) {
        System.out.println("update success!");
      }
      else {
        System.out.println("update is failure!");
      }

}
catch (SQLException e) {

}
}

//insert
public void getInsert() {
    String sql = "insert into empl(name,sex) values(" + "'guo'," + "'nan')";
    System.out.println(sql);
    try {
      stmt = conn.createStatement();
      int i = stmt.executeUpdate(sql);
      if (i > 0) {
        System.out.println("update success!");
      }
      else {
        System.out.println("update is failure!");
      }

}
catch (SQLException e) {

}
}

//delete
public void getDel() {
    String sql = "delete from empl where id =2";
    try {
      stmt = conn.createStatement();
      int i = stmt.executeUpdate(sql);
      if (i > 0) {
        System.out.println("update success!");
      }
      else {
        System.out.println("update is failure!");
      }
    }
    catch (SQLException e) {
      System.out.println(e.getMessage());
    }
}

public void closeDb() {
    try {
      rs.close();
      stmt.close();
      conn.close();
      System.out.println("the DB connection is shut down!");
    }
    catch (Exception ex) {
      ex.printStackTrace();
//      System.out.println(ex.getMessage());
    }
    finally {
      try {
        if (rs != null) {
          rs.close();
        }
        if (stmt != null) {
          stmt.close();
        }
        if (conn != null) {
          conn.close();
        }
      }
      catch (Exception ex) {
        System.out.println("关不掉数据库了 :（");
      }
    }
}

public static void main(String[] args) {
    Database db = new Database();
    ResultSet rs = db.getQuery();
    try {
//      db.getDel();
      while (rs.next()) {
        System.out.print(rs.getInt(1) + "/t");
        System.out.print(rs.getString("name") + "/t");
        System.out.print(rs.getString("sex") + "/t");
        System.out.println();
      }

      db.closeDb();
    }
    catch (Exception e) {
      e.printStackTrace();
//      System.out.println("我晕了 --||");
    }
}

}