事务处理流程

1、屏蔽自动提交功能

2、处理事务

3、恢复自动提交功能

代码实例

执行程序之前数据表的样子

public class GetConnection{
	public static void main(String[] args){
		Access2Database adb=new Access2Database();
		Connection conn=adb.getConn();	
		
		//transaction dealing
		PreparedStatement pstam=null;
		try{
			conn.setAutoCommit(false);
			String sql="delete from student where name='a' and major= ";
			pstam=conn.prepareStatement(sql);
			pstam.setString(1, "Chinese");
			pstam.executeUpdate();

			conn.rollback();
			conn.commit();
		}catch(SQLException e){
			try {
				conn.rollback();
			} catch (SQLException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			e.printStackTrace();
		}finally{
			try {
				conn.setAutoCommit(true);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}	
		
		//release the resource of the program
		try{
			pstam.close();
			conn.close();
		}catch(SQLException e){
			e.printStackTrace();
		}
	}
}

可见没有发生改变，事务回滚成功

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除此应用外，还可以保存事务处理的中间态，最后可以恢复到此中间保存状态

数据表之前的状态

看代码

import java.sql.*;

public class GetConnection{
	public static void main(String[] args){
		Access2Database adb=new Access2Database();
		Connection conn=adb.getConn();	
		
		//transaction dealing
		PreparedStatement pstam=null;
		try{
			conn.setAutoCommit(false);
			String sql="delete from student where name='a' and major= ";
			pstam=conn.prepareStatement(sql);
			pstam.setString(1, "Chinese");
			pstam.executeUpdate();
			//conn.commit();
			
			Savepoint sp=conn.setSavepoint();
			sql="insert into student(name,major,score) values('g','Math','99');";
			pstam=conn.prepareStatement(sql);
			pstam.executeUpdate();
			conn.rollback(sp);
			conn.commit();
		}catch(SQLException e){
			try {
				conn.rollback();
			} catch (SQLException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			e.printStackTrace();
		}finally{
			try {
				conn.setAutoCommit(true);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}	
		
		//release the resource of the program
		try{
			pstam.close();
			conn.close();
		}catch(SQLException e){
			e.printStackTrace();
		}
	}
}