可以在WHERE之后的Mysql查询中使用变量

Question

以下查询有效并返回结果

$query = "SELECT * FROM table WHERE District = '" . $var . "' ORDER BY Form_Date DESC";

好像我用'＃34; District＆＃34;使用变量，它不起作用

$query = "SELECT * FROM table WHERE '" . $distvar . "' = '" . $var . "' ORDER BY Form_Date DESC";

这个问题出了什么问题？我怎样才能让它发挥作用？

Answer 1

删除您正在测试的字段周围的引号，或者用反引号替换它们以避免将您从mysql解析器中误认为是可能的保留字：

$query = "SELECT * FROM `table` WHERE `" . $distvar . "` = '" . $var . "' ORDER BY Form_Date DESC";

Answer 2

试试这个：

$query = "SELECT * FROM table WHERE `" . $distvar . "` = '" . $var . "' ORDER BY Form_Date DESC";

或

$query = "SELECT * FROM table WHERE " . $distvar . " = '" . $var . "' ORDER BY Form_Date DESC";