[mysql][transaction交易] 簡單介紹

transaction(交易):就是當有兩段要執行的SQL語法，希望要嘛就兩個SQL語句都執行成功，如果其中一行出現錯誤就恢復原始資料，這時候就要使用transaction。



官方:

儲存引擎	說明
MyISAM	Default engine as of MySQL 3.23 with great performance
MEMORY	Hash based, stored in memory, useful for temporary tables
InnoDB	Supports transactions, row-level locking, and foreign keys
BerkeleyDB	Supports transactions and page-level locking
BLACKHOLE	/dev/null storage engine (anything you write to it disappears)
EXAMPLE	Example storage engine
ARCHIVE	Archive storage engine
CSV	CSV storage engine
ndbcluster	Clustered, fault-tolerant, memory-based tables
FEDERATED	Federated MySQL storage engine
MRG_MYISAM	Collection of identical MyISAM tables
ISAM	Obsolete storage engine

由表看出MyISAM沒有支援Transaction(交易)，所以即使PDO的交易函數也沒辦法使用
MYSQL引擎要換成InnoDB才行

try{
$dbh->beginTransaction();
$sth = $dbh->exec("DROP TABLE fruit");
$sth = $dbh->exec("UPDATE dessert SET name = 'hamburger'");
$dbh->commit();
}catch(Exception $e){
$dbh->rollBack();
$e->getMessage();
}