JDBC基本操作1

JDBC连接数据库

1.加载驱动

2.获取连接对象（java程序 192.168.153.1 Connection）-------mysql()

3.Statement 承载执行SQL语句,并执行(Statement 是connection创建出来)

4.数据库返回sql执行的结果

5.释放资源

添加mysql.8.0.29

找到pom.xml文件，找到<dependency>添加

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.29</version>
</dependency>

添加后右上角M刷新加载

一、连接驱动

找到App.java文件

 public static void main( String[] args )
    {
        Connection connection =null;
        PreparedStatement preparedStatement =null;
        String url = "jdbc:mysql://192.168.153.149:3306/pet";//定义一个访问路径
        String user ="root";//用户
        String pwd ="root";//密码

//          1.  加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");

//          2.获取Connection对象
            connection = DriverManager.getConnection(url,user,pwd)；                System.out.println(connection);

//                      创建dog表

create table dog(
    id int auto_increment primary key ,
    name varchar(32),
    health int,
    love int,
    strain varchar(32),
    `datetime` datetime
);

//                新增一条狗

                

 String name ="常威";
 String strain ="藏獒";
 int love=100;
 int health=100;
 Date date = new Date(1623313749000l);
 Time time = new Time(1623313749000l);
 Timestamp timestamp = new Timestamp(1623313749000l);
 String insertSql="insert into dog(name,health,love,strain,datetime)" +
         " values(?,?,?,?,?)";

//            3.Statement 承载执行SQL语句,并执行

        

preparedStatement = connection.prepareStatement(insertSql);
preparedStatement.setString(1,name);
preparedStatement.setInt(2,health);
preparedStatement.setInt(3,love);
preparedStatement.setString(4,strain);
/*preparedStatement.setDate(5,date);*/
/*preparedStatement.setTime(5,time);
preparedStatement.setTimestamp(5,timestamp);
int num = preparedStatement.executeUpdate();
if(num>0)
    System.out.println("新增成功!");

   

//删除数据
/* String deleteStr = "delete from dog where id=?";
 preparedStatement = connection.prepareStatement(deleteStr );
 preparedStatement.setInt(1,3);
 int num = prepareStatement.executeUpdate();
 if(num>0)
 System.out.println("新增成功!");
 */

        

//修改数据
/*String updateStr = "update dog set name=?,health=? where=?";
preparedStatement = connection.prepareStatement(updateStr);
preparedStatement.setString(1,"来福");
preparedStatement.setInt(2,0);
preparedStatement.setInt(3,4);
int num = preparedStatement.executeUpdate();
if (num>0)
    System.out.println("修改成功");*/

    //4.数据库返回sql执行的结果 resultSet(一个返回结果集)

//查询
    String queryStr="select id,name,health,love,strain,datetime from dog";
         preparedStatement = connection.prepareStatement(queryStr);
        ResultSet resultSet = preparedStatement.executeQuery();
        while (resultSet.next()){
            System.out.println(resultSet.getInt("id")+"\t"
                    + resultSet.getString("name")+"\t"
                    +resultSet.getInt("health")+"\t"
                    +resultSet.getInt("love")+"\t"
                    +resultSet.getString("strain")+"\t"
                    +resultSet.getString("datetime")+"\t"
                    +resultSet.getTimestamp("datetime")+"\t"

            );
        }

} catch (ClassNotFoundException e) {
    throw new RuntimeException(e);
} catch (SQLException e) {
    throw new RuntimeException(e);
}finally {
    if (preparedStatement!=null) {
        try {
            preparedStatement.close();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
    if (connection!=null){
        try {
            connection.close();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}