jdbc内容

Jdbc：java数据库连接技术

主要执行操作：连接数据库，执行sql语句，处理结果

1. Class.forName(“com.mysql.jdbc.Driver”); 执行jdbc驱动                 
2. DriverManager：驱动管理者
3. Connection：建立通道连接数据库                                          
4. Statement：用于运行SQL语句                                             
5. ResultSet：返回结果集，statement执行语句后的结果                       

例子：过程中需要try-catch                                                  

    Class.forName(“com.mysql.jdbc.Driver”);                               

    String url = “jdbc:mysql://localhost:3306/数据库名”;                

    String user = “root”; //数据库的账户                                 

    String password = “root”; //数据库的密码                             

    Conection conn = DriverManager.getConnection(url,user,password);       

    Statement statement = conn.createStatement();                          

    statement.execute(String sql); //执行语句(用于增删改查操作)            

statement.executeUpdate(String sql); //跟新数据 返回int影响行数   

    ResultSet rs = statement.executequery(String sql); //查询表

    While(rs.next){

    rs.getObject(“字段名”);

}

    //关闭原则 先开启的后关闭                                              

    rs.close();                                                            

    statement.close();                                                     

    conn.close();                                                          

                                                                           

mysql的crud 增删改查                                                      

1. 插入语句：insert into 表名(name,password) values(‘ss’,’123’);       
2. 查询语句：select * from 表名                                            
3. 删除语句：delete form 表名 where id=1  （删除id为1的数据）            
4. 修改语句：update 表名 set name=’ss’,password=’123’ where id= 1