JDBC复习

JDBC

1. 导入驱动jar包，注册驱动，获取连接
2. 定义sql
3. 获取执行sql的对象，执行sql
4. 处理结果：查询需要处理结果，增删改只需要判断count>0，有没有执行成功；
5. 释放资源

Class.forName("com.mysql.cj.jdbc.Driver");
Connection connection = DriverManager.getConnection(url,username,password);
String sql = "";
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery(sql);
resultSet.close();
statement.close();
connection.close();

List<User> list = new ArrayList();
while(resultSet.next()){
    int UserId = resultSet.getString("userId");
    User user = new User(UserId);
    list.add(user);
}

String sql = "insert into tb(name,age) values(?,?)";
String sql = "update  tb set name = ?,age = ? where id = ?";
String sql = "delete  from tb where id = ?";
statement.setString(1,name);
statement.setInt(1,age);
int count = statement.executeUpdate(sql);
System.out.println(count > 0);