在Laravel中计算MySQL数据库中行数的最快方法？

Question

I can think of a couple ways to count the number of rows in a table with Laravel (version 3).

DB::table('threads')->count();
Threads::count();
Threads::max('id');
DB::table('threads')->max('id);
DB::query('SELECT COUNT(*) FROM threads;');

Are any of these notably faster than the others? Is there any one fastest way to run this query? Later on it's going to be part of an expression: ceil(DB::table('threads')->count() / $threads_per_page); and it's executed on every page load so it's good to be optimized.

Database/table is MySQL and the InnoDB engine.

Answer 1

MAX(ID) is not the same as counting rows, so that rules out two of five alternatives.

And then it is your task to actually do a performance comparison between the remaining three methods to get the count. I'd think that actually executing an SQL statement directly might remove plenty of unnecessary ORM-layer overhead and be actually faster, but this would be premature optimization unless proven by facts.

Answer 2

DB::table('threads')->count();
Threads::count();
DB::query('SELECT COUNT(*) FROM threads;');

I was looking for the same thing. These 3 results are exactly the same query I tested it (You can watch this with laravel debugbar). Laravel perform "SELECT COUNT(*) as aggregate FROM threads"; It's already optimised with eloquent, but if you do ->get()->count() it's not optimised ! No performance difference with Threads::count();

Max('id') is totally different as it output the max id, it will never count the number of rows.

Answer 3

我不认为这真的很重要..只是在您的代码中保持一致..以任何方式都不需要在evey页面加载时运行该查询..使用一些缓存来缓存该数字..