oracle_11gr2_11 事务transaction - 四大特性(原子性,一致性,隔离性,永久性)和相应的例子来演示（oracle _ 11gr2 _ 11 事务transaction - 四大特性 (原子性, 一致性, 隔离性, 和相应的例子来演示 永久性)）.doc

oracle_11gr2_11 事务transaction - 四大特性(原子性,一致性,隔离性,永久性)和相应的例子来演示（oracle _ 11gr2 _ 11 事务transaction - 四大特性 (原子性, 一致性, 隔离性, 和相应的例子来演示 永久性)） This is a sound video, please check the headset or speaker sound output device The tutorial uses Oracle 11g Release 2 version Content: demonstrates the four main features of the transaction (atomicity, consistency, isolation, permanence) and the corresponding examples =============================================== Transfer in bank accounts is a good example of learning matters: Suppose you have 2 accounts, A accounts and B accounts. A account transfer to B account 100 yuan, (2 actions are inside, 1 is A account, minus 100, 2 is B, account is 100 dollars, and 2 actions are atomic If B account money does not increase, then the A account should not reduce the amount of money to maintain consistency. CREATE, TABLE, zhang_hao (ID, integer, zhang_hu, varchar (25), jin_e, integer); INSERT, INTO, zhang_hao, VALUES (1,A, 1000); INSERT, INTO, zhang_hao, VALUES (2,B, 500); COMMIT; Now for a delete operation, you will find that it is not really deleted Delete with Scott user SQL, DELETE, FROM, zhang_hao, where, id=2; COMMIT / / ROLLBACK; Permanent - once commit is submitted, it cannot be rolled back, and the data is actually written to the table ==================================================== When updating a data, 2 users will be updated simultaneously SQL show user; USER is SCOTT SQL, update, zhang_hao, set, jin_e=300, where, id=2; A solution to concurrency: When I update, other users can not modify it, it can be said to be coupled with an exclusive lock (isolation). SELECT * FROM, zhang_hao, FOR, UPDATE; In this way, the sys account cannot be updated in a wait state UPDATE, scott.zhang_hao, SET, jin_e=200, WHERE, id=1; ========================================================== Begin / sever in MS SQL.Transaction: consistency of control transactions, In Oracle, there are commit and exception, rollback If you want multiple statements to b