小编Mik*_*ike的帖子

$query = "SELECT distinct('case'), firstname, lastname 
            FROM cases ";

为什么"案例"不能得到回应？这是一个数字..

当查询如下时,它将回显:

$query = "SELECT case, firstname, lastname 
            FROM cases ";

!空代码在此代码中:

if (!empty($p1_firstname))
mysql_query ("INSERT INTO cases VALUES ('','$case','$date_booked','$p1_firstname','$p1_lastname','$city')");

if (!empty($p2_firstname)) 
$register_case = mysql_query ("INSERT INTO cases VALUES ('','$case','$date_booked','$p2_firstname','$p2_lastname','$city')");

但不是这个代码:

if (!empty($p1_firstname))
$passenger1 = 1;
mysql_query ("INSERT INTO cases VALUES ('','$case','$passenger1','$date_booked','$p1_firstname','$p1_lastname','$city')");

if (!empty($p2_firstname)) 
$passenger2 = 2;
$register_case = mysql_query ("INSERT INTO cases VALUES ('','$case','$passenger2','$date_booked','$p2_firstname','$p2_lastname','$city')");

即使字段为空,它仍然会执行查询.可以做些什么来解决这个问题？