package com.Project_DataBase01;

import java.sql.Connection;
import java.sql.DriverManager;

public class SelectQuery {
 
 private Connection conn;
 
 /*
  * 创建一个返回Connection的方法
  */
 public Connection getConnection(){
  try {
   Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
   System.out.println("数据库驱动加载成功");
   conn=DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=java_conn_test","sa","123456");
   if(conn==null){
    System.out.println("数据库连接失败");
    System.out.println("-----------------------");
   }else {
    System.out.println("数据库连接成功");
    System.out.println("-----------------------");
   }
  } catch (Exception e) {
   // TODO: handle exception
   e.printStackTrace();
  }
  return conn;
 }

} 

 package com.Project_DataBase01;

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

public class StartMain {
 
 private static Connection conn;

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  
  conn=new SelectQuery().getConnection();
  
  GetInsert();
  GetSelect();
  
  GetUpdate();
  GetSelect();
  
  GetDelete();
  GetSelect();
 }

 /*
  * INSERT
  */
 public static void GetInsert(){
  if(conn!=null){
   //INSERT 
   System.out.println("-----------INSERT------------");
   int x=1+(int)(Math.random()*5000);
   String insert_str="INSERT INTO tb_User (UserName,UserPwd,UserId) VALUES ('name_"+x+"','pwd_"+x+"',NEWID())";
   try {
    Statement insertstatement=conn.createStatement();
    int result= insertstatement.executeUpdate(insert_str);
    if(result>0){
     System.out.println("添加成功");
     System.out.println("-----------------------");
    }
    else {     
     System.out.println("添加失败");
     System.out.println("-----------------------");
    }
   } catch (Exception e) {
    System.out.println("添加失败");
    System.out.println("-----------------------");
    // TODO: handle exception
   }
  }
  else {
   System.out.println("请检查数据库连接");
   System.out.println("-----------------------");
  }
 }
 
 /*
  * SELECT
  */
 public static void GetSelect(){
  if(conn!=null){
   
   //SELECT
   System.out.println("-----------SELECT------------");
   String select_str=" SELECT * FROM tb_User ";
   try {
    PreparedStatement selectps=conn.prepareStatement(select_str);
    ResultSet rs=selectps.executeQuery();
    while (rs.next()) {
     String name=rs.getString("UserName");
     String pwd=rs.getString("UserPwd");
     String UserId=rs.getString("UserId");
     System.out.println(name+"\t"+pwd+"\t"+UserId);
    }
    System.out.println("查询成功");
    System.out.println("-----------------------");
   } catch (Exception e) {
    // TODO: handle exception
    System.out.println("查询失败");
    System.out.println("-----------------------");
   }
  }
  else {
   System.out.println("请检查数据库连接");
   System.out.println("-----------------------");
  }
 }

 /*
  * UPDATE
  */
 public static void GetUpdate(){
  if(conn!=null){
   //UPDATE
   System.out.println("-----------INSERT------------");
   String update_str="UPDATE tb_User SET UserPwd=UserPwd+'xxxxxxxx' WHERE UserId='fa562573-218a-4205-b67d-ebdfac3f8329'";
   try {
    Statement updatestatement=conn.createStatement();
    int result=updatestatement.executeUpdate(update_str);
    if(result>0){
     System.out.println("修改成功！");
     System.out.println("-----------------------");
    }else {
     System.out.println("修改失败");
     System.out.println("-----------------------");
    }
   } catch (Exception e) {
    // TODO: handle exception
    System.out.println("修改失败");
    System.out.println("-----------------------");
   }
  }
  else {
   System.out.println("请检查数据库连接");
   System.out.println("-----------------------");
  }
 }
 
 /*
  * DELETE
  */
 public static void GetDelete(){
  if(conn!=null){
   //DELETE 
   System.out.println("-----------DELETE------------");
   String delete_str="DELETE tb_User WHERE UserId!='fa562573-218a-4205-b67d-ebdfac3f8329'";
   try {
    Statement deletestatement=conn.createStatement();
    int result=deletestatement.executeUpdate(delete_str);
    if(result>0){
     System.out.println("删除成功！");
     System.out.println("-----------------------");
    }else {
     System.out.println("删除失败");
     System.out.println("-----------------------");
    }
   } catch (Exception e) {
    // TODO: handle exception
    System.out.println("删除失败");
    System.out.println("-----------------------");
   }
  }
  else {
   System.out.println("请检查数据库连接");
   System.out.println("-----------------------");
  }
 }

}