mysqli_query - 返回值

问题描述

我正在使用 PHP 函数 mysqli_query 运行 SELECT 查询.

I am using the PHP function mysqli_query to run a SELECT query.

如果查询运行成功，但查询没有找到匹配项，mysqli_query 返回什么?

What does mysqli_query return if the query runs successfully, but the query finds no matches?

推荐答案

根据 手册:

失败时返回 FALSE.对于成功的 SELECT、SHOW、DESCRIBE 或 EXPLAIN 查询，mysqli_query() 将返回一个 mysqli_result 对象.对于其他成功的查询，mysqli_query() 将返回 TRUE.

Returns FALSE on failure. For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object. For other successful queries mysqli_query() will return TRUE.

运行但不返回结果的查询仍被视为成功查询"，因为该查询确实在数据库中运行并且空结果集是合法响应.这意味着查询仍然会返回一个 mysqli_result 对象，如果你检查它的行数(通过面向对象风格的 $result->num_rows 或 mysqli_num_rows($result) 在程序风格中)它将返回 0.

A query that runs but returns no results is still considered a "successful query", since the query did run in the database and an empty result set is a legitimate response. This means the query will still return a mysqli_result object, and if you check its row count (either via $result->num_rows in the object-oriented style or mysqli_num_rows($result) in the procedural style) it will return 0.

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