1.
import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.sql.Statement; public class Demo{ public static void main(String[] args) throws Exception{ //1.加载驱动 Class.forName("com.mysql.jdbc.Driver"); //2.配置连接信息 String url="jdbc:mysql://localhost:3306/shop?useUnicode=true&useSSL=true&character=utf8"; String user="root"; String password="12345"; //3.建立连接 Connection con= DriverManager.getConnection(url,user,password); //4.创建读取对象
//PreparedStatement ps= con.prepareStatement(sql)//预加载; ps.executeQuery()执行;
//PreparedStatement ps= con.prepareStatement(“update user set password=? where username=? ”) ps.setObject(1,"1234");ps.setObject(2,"chen");//预加载; ps.executeQuery()执行;
Statement st= con.createStatement();
//5.创建查询语句
String sql="select * from user";
//6.执行语句操作
ResultSet result= st.executeQuery(sql);
//7.获取数据并打印
while(result.next())
{ System.out.print(result.getObject(1)+result.getObject(2)+....);
//8.关闭连接
con.close(); } }
2.事务
创建连接后,
关闭自动提交开启事务:
connection.setAutoCommite(false);
执行数据库操作(增删改查)
connnection.commit()---提交所有操作;
Exception 处理 :
connection.rollback();
finally :
connection.close();