public classJdbcDom{/**

* 建表

* @throws Exception*/@Testpublic voidjianBiao() throws Exception {//贾：加载JDBC驱动(用反射的方式加载Driver(驱动)类)

Class.forName("com.mysql.jdbc.Driver");//联：连接数据库(通过驱动管理器获取数据库连接("数据库地址","数据库账号","数据库秘密"))

Connection connection = DriverManager.getConnection("jdbc:mysql:///2019_9_9","root","root");//欲：获得语句对象,//上下语句是有关联的，只有获取了数据库连接对象才能拿到语句对象；//获取语句对象，才能将sql语句执行到数据库

Statement cs =connection.createStatement();//执：执行sql语句(cs.执行数据更新(CREATE TABLE 表名 (字段名1 数据类型(数据长度) primary key not null AUTO_INCREMENT,字段名2 数据类型(数据长度),....)))//primary key:设为主键//not null:不为空//AUTO_INCREMENT:自增

cs.executeUpdate("CREATE TABLE tabeName2 (ID int primary key not null AUTO_INCREMENT,name varchar(10),age int)");//事：事务关闭

cs.close();//关闭语句连接

connection.close();//关闭数据库连接

}/**

* 删除指定id的数据

* @throws Exception*/@Testpublic voidremoveValue() throws Exception{//贾

Class.forName("com.mysql.jdbc.Driver");//联

Connection connection = DriverManager.getConnection("jdbc:mysql:///2019_9_9","root","root");//欲

Statement cs =connection.createStatement();//执

cs.executeUpdate("DELETE FROM tabename2 WHERE id=1");

System.out.println("删除完成");//事

cs.close();

connection.close();

}/**

* 添加数据

* @throws Exception*/@Testpublic voidaddValue() throws Exception{//贾

Class.forName("com.mysql.jdbc.Driver");//联

Connection connection = DriverManager.getConnection("jdbc:mysql:///2019_9_9","root","root");//欲

Statement cs =connection.createStatement();//执

cs.executeUpdate("INSERT INTO tabename2 VALUES (null,'我去',20)");//事

cs.close();

connection.close();

}/**

* 根据id修改数据

* @throws Exception*/@Testpublic voidsetValue() throws Exception{//贾

Class.forName("com.mysql.jdbc.Driver");//联

Connection connection = DriverManager.getConnection("jdbc:mysql:///2019_9_9","root","root");//欲

Statement cs =connection.createStatement();//执

cs.executeUpdate("UPDATE tabename2 SET name='C',age=3 WHERE id=3");//事

cs.close();

connection.close();

}/**

* 通过ID查询数据

* @throws Exception

**/@Testpublic voidlookValue() throws Exception {//贾

Class.forName("com.mysql.jdbc.Driver");//联

Connection connection = DriverManager.getConnection("jdbc:mysql:///2019_9_9","root","root");//欲

Statement cs =connection.createStatement();//执

ResultSet e = cs.executeQuery("SELECT * FROM tabeName2 WHERE id=1");//要打印数据；判断e.next()不能少。

if(e.next()){

System.out.println(e.getInt("id")+e.getString("name")+e.getInt("age"));

}else{

System.out.println("没有");

}//事

cs.close();

connection.close();

}

/**

*查询所有数据

*

*/

@Testpublic voidlookAllValue() throws Exception{//贾

Class.forName("com.mysql.jdbc.Driver");//联

Connection connection = DriverManager.getConnection("jdbc:mysql:///2019_9_9","root","root");//欲

Statement cs =connection.createStatement();//执

ResultSet executeQuery = cs.executeQuery("SELECT * FROM tabename2");while(executeQuery.next()) {

System.out.println(executeQuery.getInt("id")+"__"+executeQuery.getString("name")+"__"+executeQuery.getInt("age"));

}//事

cs.close();

connection.close();

}

}