变量

Question

如何在变量中设置值？

我尝试了“SET checked = 1”，但收到了这个错误：

  

警告：mysql_fetch_array（）期望参数1为资源，

我正在使用mysql / PHP

IF NOT EXISTS 
    (   SELECT  *
        FROM    training2subjects 
        WHERE   trainingID = ".$_GET['trainingID']."
        AND  subjectID = ".$subIndex["id"]."
    )
    BEGIN
            INSERT INTO training2subjects (trainingID, subjectID) 
            VALUES (".$_GET['trainingID'].", ".$subIndex["id"]." )
    END;
ELSE
    SET checked = 1

$query= mysql_query($query);
$index = mysql_fetch_array($query);
$checked = ($query) OR ($index['checked'] == 1) ? "checked" : "";