Question

我对MySQL中的行数感到困惑。 phpMyAdmin和count查询返回的总行数不同。

我的表结构是InnoDB。

Showing rows 0 - 24 (655537 total, Query took 0.1527 seconds.)

这是浏览表时的结果。

我的计数查询是

SELECT count(*) FROM `table_name`

这将返回为602030

Answer 1

When you browse using a tool, like phpmyadmin or heidiSQL, a query like this is executed:

SHOW TABLE STATUS LIKE 'table';

this value is inaccurate and if you run it many times, it always gives different results.

on the contrary the query:

select count(*) from table

is actually counting the records, and gives a correct result.

一些存储引擎（例如MyISAM）存储精确计数。对于其他存储引擎，例如InnoDB，此值为近似值，可能与实际值相差40％到50％在这种情况下，请使用SELECT COUNT（*）获得准确的计数。

Answer 2

MySQL说：通过INNODb，总数仅是计数的近似值。