从"mysql_query"查询结果中计算行数 [英] Count rows from results of a "mysql_query"

问题描述

如果我有这个:

$results = mysql_query("SELECT * FROM table_name WHERE id=$id");

那么有什么方法可以检查有多少行的字段值为"Private"或"Company"?

is there then any way to check how many rows which have a field-value of "Private" or "Company" ?

我需要向用户显示找到的私人"和公司"记录数量，而无需进行其他查询. (有一个名为"ad_type"的列，其中包含私人"或公司")

I need to show the user how many "Private" and "Company" records where found, without making another query. (There is a column called 'ad_type' which contains either "private" or "company")

我已经知道用于计数所有行的mysql_num_rows！

I already know the mysql_num_rows for counting all rows!

有五十万条记录！因此，也许结果迭代很慢，您认为呢?

There are 500thousand records! So maybe an iteration through the result is slow, what do you think?

感谢所有帮助:)

推荐答案

上面的答案非常有用，但是如果您要处理大量数据，当前检查的答案将非常无效.

The above answers are great and all, but the currently checked answer will work very inefficiently should you be dealing with a large amount of data

上述答案的示例(通过Gal)

Example of the above answer (via Gal)

$results = mysql_query("SELECT *,(SELECT COUNT(*) FROM table_name WHERE column=$value) count FROM table_name WHERE id=$id");

这一切都很好，它可以返回您需要的内容，但是明显的设计缺陷是，使您的SQL Server返回结果然后再返回它们，然后仅查看计数对于大量数据而言是非常低效的.

It's good and all, and it returns what you need but the obvious design flaw is that making your SQL server return the results then re-return them and look at just the count is very inefficient for large amounts of data.

只需执行以下操作:

$results = mysql_query("SELECT * FROM table_name WHERE column=$value");
$num_rows = mysql_num_rows($result);

从长远来看，它会产生相同的结果，并且效率更高，而且还会处理大量数据.

It will yield the same results and be much more efficient in the long run, additionally for larger amounts of data.

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