MySQL输出CSV并从CSV更新 - MySQL output CSV and update from CSV

MySQL output CSV and update from CSV

本文关键字：CSV 更新并从 MySQL 输出 | 更新日期: 2023-09-27

下面有一个查询，我从数据库中选择一个ID，然后用1更新该ID的字段，以指示该记录已被处理。我现在需要执行相同的过程，但选择50个ID并以CSV格式输出它们，然后再次用1更新每个记录，以指示这些记录已被处理。感谢您的帮助，我不确定最有效的方法。

$result = mysql_query("SELECT `id` FROM `t_ids` WHERE `f_fetched` IS null LIMIT 1");
while($row = mysql_fetch_array($result))
$f_id = $row['id'];
mysql_query("UPDATE t_ids SET f_fetched = '1' WHERE id = '$f_id'");

您可以使用类似的东西

$result = mysql_query("SELECT `id` FROM `t_ids` WHERE `f_fetched` IS null LIMIT 50");
$processed_ids = array();
while($row = mysql_fetch_array($result))
{
    //do whatever processing you need to with that id
    //add the id to the $processed_ids array
    $processed_ids[] = $row['id'];
}
$ids = implode(",", $processed_ids);  //create a comma-delimited string of ids.
//update all rows in 1 query
mysql_query("UPDATE t_ids SET f_fetched = '1' WHERE id IN ($ids)");

为什么不直接使用：

mysql_query("UPDATE t_ids SET f_fetched = '1' WHERE  `f_fetched` IS null");