本文介绍了设置AutoCommit和begin_work / rollback是否相同?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
这个问题是关于Perl DBI(我在MySQL中使用它)。
This question is about Perl DBI (I use it with MySQL).
我想要以下代码:
{
local $dbh->{AutoCommit} = 0;
...
if(...) {
$dbh->rollback;
}
...
}
它将按预期工作吗? (我的意思是回滚后没有多余的提交)$ dbh-> {AutoCommit}是否与$ dbh-> begin_work和$ dbh-> rollback兼容?
Will it work as expected? (I mean no superfluous commit after rollback) Is $dbh->{AutoCommit} compatible with $dbh->begin_work and $dbh->rollback?
推荐答案
是的,您可以这样做,但是为什么要这么做。为什么不直接调用begin_work然后提交或回滚。即使已启用AutoCommit,它们也可以正常工作。
Yes, you can do that but why would you want to. Why not just call begin_work and then commit or rollback. They work fine even if AutoCommit is on.
use strict;
use warnings;
use DBI;
use Data::Dumper;
my $h = DBI->connect();
eval {
$h->do(q/drop table mje/);
};
$h->do(q/create table mje (a int)/);
my $s = $h->prepare(q/insert into mje values(?)/);
foreach my $it(1..2) {
{
local $h->{AutoCommit} = 0;
$s->execute($it);
if ($it == 2) {
$h->rollback;
} else {
$h->commit;
}
}
}
my $r = $h->selectall_arrayref(q/select * from mje/);
print Dumper($r);
outputs:
$VAR1 = [
[
1
]
];
但以下内容对我来说更好:
but the following looks better to me:
foreach my $it(1..2) {
$h->begin_work;
$s->execute($it);
if ($it == 2) {
$h->rollback;
} else {
$h->commit;
}
}
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