MySQL Transaction implementation method steps

Requirements Description:

Case background: In the course of bank transfer, accidents are unavoidable. To avoid unnecessary losses caused by an accident, the transaction is handled in the same way:

A account has an existing balance of $1000 and a transfer of $500 to a balance of 200 B accounts. Possible for a reason:

A account has an error while deducting the transfer amount, using a transaction rollback to return to the initial state

A after the account has successfully deducted the transfer amount, the B account adds the transfer amount error, using the transaction rollback to the initial state

Tip: First build the data table account, the field includes the name (username), the balance (money), and then use the transaction to handle the above two cases respectively.

#创建账户表   create table if not exists account (    id  INT (one) Not null auto_increment primary key,    username varchar ( Not null,    money decimal (9,2)   ) engine=innodb;   #插入用户数据   insert into account (Username,money) VALUES (' A ', 1000.00);   insert into  account (Username,money) VALUES (' B ', 200.00);     /* transaction Processing */  #   A account remittance failure   SELECT * FROM account;   #第一步   Close transaction autocommit mode   SET  autocommit=0;   #第二步   Start transaction   START TRANSACTION;   #第三步   Discovery Remittance failed, Rolling a transaction back rollback | |    Remittances successfully commit   the event #假设语法错误   update account set money=money-500  where username= ' A ';   select * from account;  update account  set&nbsP;money=money+200 where username= ' B ';  rollback;   #第四步   Restore automatic submission of MySQL database   SET autocommit=1;  SELECT * FROM account;        /*b Receive remittance failed */  select *from account ;  set autocommit  =0;  start transaction;  update account set money=money-500  where username= ' A ';  select * from account ;   #假设语法错误    update account set money=money+200 where username = ' B ';   rollback;  set autocommit =1;  select * from account;      #清除数据   <pre name= "code"  class= "SQL" >TRUNCATE account;

Note:

Use if not exists to create a data table interpretation

MySQL Transaction implementation method steps