Question

好的，我很困惑。我有一些代码在数据库表中搜索用户名，然后使用if else语句运行一些代码，具体取决于是否找到用户。我的代码如下。问题是代码甚至没有看到if else语句，我不知道为什么。任何帮助表示赞赏。

$sqluser = "select * from users where username='" . $user ."'"; //Searching to see if the user is in the database
echo $sqluser . "<br><br>"; //writes out the select statement to make sure it is correct
$query = mssql_query($sqluser); //returns the results
$num_rows = mssql_num_rows($query); //gets the number of rows returned

echo $num_rows; //writes out the number of rows

if ($num_rows==0) //determines what happens next if the user exists or not
{
    //displays an error box if the user doesn't exist
    echo "<script type=text/javascript>";
    echo "alert('That user doesn't exist. Please try again.')";
    echo "</script>";
}
else
{
    //will be code to run if the user does exist
    echo "<script type=text/javascript>alert('Testing.')</script>";
}

Answer 1

我无法添加评论。所以我会把它写成答案。

由于您声明警报JavaScript正在页面源中显示，这意味着PHP中的IF / ELSE语句正常工作。问题在于单引号。单引号警报功能中有一个引号。因此，无法执行JavaScript警报功能。

echo "alert('That user doesn't exist. Please try again.')";

尝试使用此代替

echo "alert('That user doesn\'t exist. Please try again.');";

PHP如果Else语句不适用于数据库

1 个答案: