php - mysqli_use_result() 和并发性

Question

根据mysqli_use_result处的文档

One should not use mysqli_use_result() if a lot of processing on the client side is performed, since this will tie up the server and prevent other threads from updating any tables from which the data is being fetched.

这仅适用于 myISAM 表还是也适用于 InnoDB？

Answer 1

刚刚检查:MyISAM 锁定，InnoDB 未锁定:

<?php
        $db = new mysqli() or die ("Cannot connect: " . mysqli_connect_error() . "\n");
        $query = "SELECT * FROM mytable";
        $db->real_query($query) or die ("Cannot fetch: $db->error\n");
        $result = $db->use_result() or die ("Cannot use result: $db->error\n");
        while($row = $result->fetch_row()) {
                print join("\t", $row) . "\n";
                usleep(1000000);
        }
?>

这会锁定:

UPDATE mytable /* isam */ SET myvalue = 'test' WHERE id = 100

这不会:

UPDATE mytable /* innodb */ SET myvalue = 'test' WHERE id = 100