我有一个循环遍历旧数据库并将新行迁移到新数据库。两个数据库仍将使用一段时间，因此这应该是可以定期运行的同步。理想情况下，每小时多次检查更改：
public function sync_rates()
{
// Disable runtime limit
set_time_limit(0);
$persist_count = 0; // Keep track of home many properties are ready to be flushed
$flush_count = 1; // Persist and flush the properties in groups of...
echo memory_get_usage() . "<br />";
$legacy_rates = $this->doctrine->mssql
->getRepository('Entity\MSSQL\TblPropertyRent')
->getAllIDs();
echo memory_get_usage() . " after IDs<br />";
foreach ($legacy_rates as $legacy_id)
{
echo memory_get_usage() . " in loop<br />";
// Instantiate the rate
$legacy_rate = $this->doctrine->mssql
->getRepository('Entity\MSSQL\TblPropertyRent')
->findOneBy(array(
'proprentID' => $legacy_id['proprentID']
));
// Lets see if this rate already exists in the new database. If it does, we'll just use that.
$rate = $this->doctrine->em
->getRepository('Entity\Beaverusiv\PropertyRate')
->findOneById($legacy_id);
// If the rate from the legacy database does not exist in the new database, let's add it.
if (! $rate)
{
$rate = new Entity\Beaverusiv\PropertyRate;
$rate->setId($legacy_id['proprentID']);
$rate->setName($legacy_rate->getRentName());
$rate->setRate($legacy_rate->getRentRate());
// Have to do it this way with a new DateTime object because MSSQL stores its dates
// - in a different format to MySQL. Refer to the getStartdate() function to see
// - what needs to be done to the date.
$rate->setDateStart(new DateTime($legacy_rate->getStartdate()));
$rate->setDateEnd(new DateTime($legacy_rate->getEnddate()));
$rate->setPropertyId($legacy_rate->getPropertyID());
// If override is null or 0, use default (=2)
$rate->setMinimumNights($legacy_rate->getMinNightsOvride()?$legacy_rate->getMinNightsOvride():2);
$rate->setDateUpdated(new DateTime($legacy_rate->getDateadded()));
// Persist this feature, ready for flushing in groups of $persist_bunch
$this->doctrine->em->persist($rate);
$persist_count++;
}
unset($legacy_rate);
// Don't know if I can do this! Does Doctrine need that variable after I've persisted it?
unset($rate);
// If the number of properties ready to be flushed is the number set in $flush_count, lets flush these properties
if ($persist_count == $flush_count) {
// This makes it run a LOT slower!
// Get memory under control so we don't need to do this.
$this->doctrine->em->flush();
$this->doctrine->em->clear();
$this->doctrine->mssql->clear();
$persist_count = 0;
die(); //Here so I don't have to wait long.
}
}
// Flush any remaining properties
$this->doctrine->em->flush();
}
内存使用意味着在向表中输入新行之前内存不足。新的目前有12,300行，旧表中有不到40,000行。
目前的输出如下：
1810464
16618448 after IDs
16618448 in loop
18144344 in loop
18152368 in loop
18161920 in loop
...
131038824 in loop
131046832 in loop
131054824 in loop
131062816 in loop
Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 8388608 bytes) in
/mnt/code/beaverusiv/vendor/doctrine/dbal/lib/Doctrine/DBAL/Types/DateTimeType.php on line 53
答案 0 :(得分：1)
我终于开始工作了。当我提高费率时开始大约56MB，然后在30,944次插入后达到58MB。插入需要大约17秒并且循环而不需要任何更改需要~9秒。
/**
* Date comes from MSSQL database in a weird format
* - where microseconds are only 3 digits long when
* - MySQL expects 6. To counteract this we take the
* - AM/PM off the end and the first 20 characters
* - off the start, which should give us the datetime
* - without the microseconds. Concatenate this and
* - return a DateTime object.
* @param string $date
* @return DateTime
*/
private function _formatMSSQLDate($date) {
// Date is null or empty
if(!$date) return false;
// Date isn't the right length
if(26 != strlen($date)) return false;
$am_pm = substr($date, -2);
$date = substr($date, 0, 20);
return new DateTime($date.$am_pm);
}
public function sync_rates()
{
// Disable runtime limit
set_time_limit(0);
$persist_count = 0; // Keep track of home many properties are ready to be flushed
$flush_count = 100; // Persist and flush the properties in groups of...
$legacy_rates = $this->doctrine->mssql
->getRepository('Entity\MSSQL\TblPropertyRent')
->findAllNew();
$this->doctrine->mssql->clear();
foreach ($legacy_rates as $i => $legacy_rate)
{
// Lets see if this rate already exists in the new database. If it does, we'll just use that.
$rate = $this->doctrine->em
->getRepository('Entity\Beaverusiv\PropertyRate')
->findOneById($legacy_rate['proprentID']);
// If the rate from the legacy database does not exist in the new database, let's add it.
if (!$rate) {
$rate = new Entity\Beaverusiv\PropertyRate;
$rate->setId($legacy_rate['proprentID']);
$rate->setName($legacy_rate['rent_name']);
$rate->setRate($legacy_rate['rent_rate']);
// Have to do it this way with a new DateTime object because MSSQL stores its dates
// - in a different format to MySQL. Refer to the _formatMSSQLDate() function to see
// - what needs to be done to the date.
$rate->setDateStart($this->_formatMSSQLDate($legacy_rate['startdate']));
$rate->setDateEnd($this->_formatMSSQLDate($legacy_rate['enddate']));
$rate->setPropertyId($legacy_rate['propertyID']);
// If override is null or 0, use default (=2)
$rate->setMinimumNights($legacy_rate['min_nights_ovride']?$legacy_rate['min_nights_ovride']:2);
$rate->setDateUpdated($this->_formatMSSQLDate($legacy_rate['dateadded']));
// Persist this feature, ready for flushing in groups of $persist_bunch
$this->doctrine->em->persist($rate);
$persist_count++;
} else {
$this->doctrine->em->detach($rate);
unset($legacy_rates[$i]);
}
// If the number of properties ready to be flushed is the number set in $flush_count, lets flush these properties
if ($persist_count == $flush_count) {
$this->doctrine->em->flush();
$this->doctrine->em->clear();
$persist_count = 0;
}
}
// Flush any remaining properties
$this->doctrine->em->flush();
}
与存储库中的此功能相结合：
public function findAllNew() {
$DQL = <<< DQL
SELECT f.proprentID,
f.rent_name,
f.rent_rate,
f.startdate,
f.enddate,
f.propertyID,
f.min_nights_ovride,
f.dateadded
FROM Entity\MSSQL\TblPropertyRent f
DQL;
try{
$rates = $this->_em
->createQuery($DQL)
->getArrayResult();
} catch(\Exception $e){
$rates = false;
}
return $rates;
}