python-database mysql

6. Affairs

• Transactions are only supported for databases or tables using the Innodb database engine in MySQL
• Transaction processing can be used to maintain the integrity of the database, ensuring that batches of SQL statements are either all executed or not executed at all
• Transactions are used to manage insert, update, delete statements

6.1 Characteristics of transactions:

• 1. The atomicity of transactions: a set of transactions, either successful or withdrawn.
• 2. Stability  : If there is illegal data (foreign key constraints, etc.), the transaction is withdrawn.
• 3. Isolation: Transactions run independently. If the result of a transaction affects other transactions, then other transactions will be withdrawn. 100% isolation of transactions at the expense of speed.
• 4. Reliability: After the software and hardware crash, the InnoDB data table driver will use the log file to reconstruct and modify it.

Use transactions in the Mysql console to operate

begin;
insert into a(a) values(555);
rollback;

Of course, if the above data is OK, just enter the commit to submit the command;