SQL查询中的变量被视为列

Question

我使用XCRUD框架。

我有一个问题：

$xcrud->query('SELECT * FROM table2 WHERE category IN (SELECT category FROM table1 WHERE '.$login_session.' = username)');

我一直收到以下错误：

 Unknown column 'userx' in 'where clause'

Userx是变量的值。

我也试过

$xcrud->query('SELECT * FROM table2 WHERE category IN (SELECT category FROM table1 WHERE '$login_session' = username)');

和

$xcrud->query('SELECT * FROM table2 WHERE category IN (SELECT category FROM table1 WHERE $login_session = username)');

我无法让我的查询工作。该变量被视为一个列。

Answer 1

像这样更改查询

$xcrud->query('SELECT * FROM table2 WHERE category IN (SELECT category FROM table1 WHERE username ="'.$login_session.'" )');

Answer 2

试试这个;）

$xcrud->query("SELECT * FROM table2 WHERE category IN (SELECT category FROM table1 WHERE '".$login_session."' = username)");

Answer 3

您需要在MYSQL-Queries中转义字符串。

where columnName = 'value' 

Answer 4

$xcrud->query("SELECT * FROM table2 WHERE category IN (SELECT category FROM table1 WHERE username = $login_session)");

Answer 5

$ xcrud-＆gt; query（“SELECT * FROM table2 WHERE category IN（SELECT category FROM table1 WHERE userx = $ login_session）”）;