mysql--事务demo1----

Posted 2020-08-27

package com.etc.entity;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Savepoint;

import org.junit.Test;

import com.etc.utils.JDBCUtil;

public class TransactionDemo1 {
//@Test
public void testTransaction1()
{
	Connection conn=null;
	PreparedStatement st=null;
	ResultSet rs=null;
	
	try {
		conn = JDBCUtil.getConnection();
		conn.setAutoCommit(false);//通知数据库开启事务
		String sql1 = "update account set money=money-100 where name=‘A‘";
		st = conn.prepareStatement(sql1);
		st.executeUpdate();
		String sql2 = "update account set money=money+100 where name=‘B‘";
		st = conn.prepareStatement(sql2);
		st.executeUpdate();
		conn.commit();//通知提交事务
		System.out.println("成功！");
	} catch (Exception e) {
		e.printStackTrace();
	}
	finally{
		JDBCUtil.close(rs, st, conn);
	}
	
}
//@Test
public void testTransaction2()
{
	Connection conn=null;
	PreparedStatement st=null;
	ResultSet rs=null;
	try {
		conn = JDBCUtil.getConnection();
		conn.setAutoCommit(false);//通知数据库开启事务
		String sql1 = "update account set money=money-100 where name=‘A‘";
		st = conn.prepareStatement(sql1);
		st.executeUpdate();
		int i=1/0;//异常语句   事务不能提交   数据库自动回滚
		String sql2 = "update account set money=money+100 where name=‘B‘";
		st = conn.prepareStatement(sql2);
		st.executeUpdate();
		conn.commit();//通知提交事务
		System.out.println("成功！");
	} catch (Exception e) {
		e.printStackTrace();
	}
	finally{
		JDBCUtil.close(rs, st, conn);
	}
	
}
//@Test
public void testTransaction3()
{
	Connection conn=null;
	PreparedStatement st=null;
	ResultSet rs=null;
	try {
		conn = JDBCUtil.getConnection();
		conn.setAutoCommit(false);//通知数据库开启事务
		String sql1 = "update account set money=money-100 where name=‘A‘";
		st = conn.prepareStatement(sql1);
		st.executeUpdate();
		int i=1/0;//异常语句
		String sql2 = "update account set money=money+100 where name=‘B‘";
		st = conn.prepareStatement(sql2);
		st.executeUpdate();
		conn.commit();//通知提交事务
		System.out.println("成功！");
	} catch (Exception e) {
		try {
			conn.rollback();//异常发生后   手动通知数据库事务回滚
		} catch (SQLException e1) {
			e1.printStackTrace();
		}
		e.printStackTrace();
	}
	finally{
		JDBCUtil.close(rs, st, conn);
	}
	
}
@Test  //sql1有效；sql2无效；sql3无效；
public void testTransaction4()
{
	Connection conn=null;
	PreparedStatement st=null;
	ResultSet rs=null;
	Savepoint sp=null;//事务回滚点
	try {
		conn = JDBCUtil.getConnection();
		conn.setAutoCommit(false);//通知数据库开启事务
		
		String sql1 = "update account set money=money-100 where name=‘A‘";
		st = conn.prepareStatement(sql1);
		st.executeUpdate();
		
		sp=conn.setSavepoint();//设置事务回滚点
		
		String sql2 = "update account set money=money+100 where name=‘B‘";
		st = conn.prepareStatement(sql2);
		st.executeUpdate();
		
		int i=1/0;//异常语句
		String sql3 = "update account set money=money+100 where name=‘C‘";
		st = conn.prepareStatement(sql3);
		st.executeUpdate();
		
		conn.commit();//通知提交事务
		
	} catch (Exception e) {
		try {
			conn.rollback(sp);//回滚到事务回滚点
			conn.commit();//回滚之后提交
		} catch (SQLException e1) {
			
			e1.printStackTrace();
		}
		e.printStackTrace();
	}
	finally{
		JDBCUtil.close(rs, st, conn);
	}
	
}
}