大写函数在php中不起作用

Question

我有一个PHP文件，我想在其中将用户输入转换为大写字母，所以我使用了PHP的strtoupper（）函数，但它无法正常工作。这是我的代码

$eno =@$_SESSION['eno'];
$eno =strtoupper($eno);

现在将它插入数据库时​​，它仍然是小写字母。这是插入查询。

$sql="INSERT INTO `student_info`(`student_no`,`High_School_Name`, `Year_Of_Passing`, `Higher_Secondary_School_Name`, `Year_Of_Passing1`, `Enrollment_Number`, `Roll_Number`, `Current_Course`, `Current_Sem`, `Current_section`, `Enrollment_Year`, `Alternate_Email`)VALUES('$studentno','$High_School_Name','$Year_Of_Passing10','$Higher_Secondary_School_Name','$Year_Of_Passing12','$eno','$Roll_Number','$Current_Course','$Current_Sem','$Current_section','$Enrollment_Year','$Alternate_Email' )";

Answer 1

 $eno='vikram';
 echo $eno =strtoupper($eno);

 $sql="INSERT INTO `student_info`(`student_no`,`High_School_Name`, `Year_Of_Passing`, `Higher_Secondary_School_Name`, `Year_Of_Passing1`, `Enrollment_Number`, `Roll_Number`, `Current_Course`, `Current_Sem`, `Current_section`, `Enrollment_Year`, `Alternate_Email`)VALUES('".$studentno."','".$High_School_Name."','".$Year_Of_Passing10."','".$Higher_Secondary_School_Name."','".$Year_Of_Passing12."',ucase('".$eno."'),'".$Roll_Number."','".$Current_Course."','".$Current_Sem."','".$Current_section."','".$Enrollment_Year."','".$Alternate_Email."' )";

在查询中使用此功能：选择UCASE（＆＃39; vikram＆＃39;）

Answer 2

没有问题

echo $eno;

..看看结果。