sql直接获取表中的行数的方法 [英] sql direct way to get number of rows in table
问题描述
再次stackoverflow的人们。
我有一个例程,该例程有一个步骤,我发现不必要的
可以说您要从图库中获取所有图像,并限制每页的图像数量。
$ db = PDO对象
$ start =(pagenum x每页图像)
$ limit =(每页图像)
$ itemsdata = $ db-> query( SELECT id,name from gallery LIMIT $ start,$ limit)-> fetchAll();
$ numitems = $ db-> query( SELECT id FROM gallery)-> rowCount();
$ imgsdata
是所有例如画廊中的图像。
$ numimgs
是图库中图像的数量。
您需要 $ imgsdata
在数组中的每个图像上执行foreach循环,而需要
$ numimgs
来生成页面编号(例如<< 1 2 3 4 >>)
我的怨恨与 $ db-> ; query( SELECT id FROM gallery)-> rowCount();
感觉完全像是一种作弊,没有直接的方法来获取行数在表中,类似于 SELECT gallery.Rows
?
ps当前,我正在使用SQLite,但MySQL和PostgreSQL也需要它。
这将告诉您行数:
从库
$ p中选择COUNT(*) $ p>
Hi again people of stackoverflow. I have a routine that has a step that I find unnecessary lets say you want to get all the images from a gallery, and limit a certain number of images per page.
$db = PDO object $start = (pagenum x images per page) $limit = (images per page) $itemsdata = $db->query("SELECT id,name FROM gallery LIMIT $start,$limit")->fetchAll(); $numitems = $db->query("SELECT id FROM gallery")->rowCount();
$imgsdata
is a array of all the images in a gallery for example.$numimgs
is the number of images that the gallery has.you would need
$imgsdata
to do a foreach loop on each image in the array, while$numimgs
is needed to generate the page numbering (e.g. << 1 2 3 4 >>)my grudge is with
$db->query("SELECT id FROM gallery")->rowCount();
It feels completely like some sort of cheat, isn't there a direct way to get the number of rows in a table, something likeSELECT gallery.Rows
?p.s. currently I'm using SQLite, but I'd need it for MySQL and PostgreSQL as well.
解决方案This will tell you the number of rows:
SELECT COUNT(*) FROM gallery
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