我有两个表
- 学生表格
- csci01members表
我将把学生记录放在csci01成员中，我的代码没有语法错误。但它总是被困在"用户已经是会员了"。即使他不是，我也已经有了添加记录的代码。
但我需要一个错误陷阱，这样如果用户已在csci01members表中。它无法添加记录或他无法查看csci01的成员，因此该成员将不会被看到在添加到表的列表中。
<?php
$errors="";
if(isset($_GET['add']))
{
$con = mysql_connect("localhost","root","");
if(!$con)
{ die("could not connect to server".mysql_error()); }
mysql_select_db("login", $con);
if (empty($errors)){
$check = mysql_query("SELECT * from csci01members");
$check_count = mysql_num_rows($check);
if ($check_count == 1) {
die (" The user is already a member.");
}
}
$result = mysql_query("SELECT * from students where username='$_GET[add]'");
$result_count = mysql_num_rows($result);
if ($result_count == 0) {
echo "<font color=red><br /> The user doesn't exists.</font>";
}
else
{
while($row = mysql_fetch_array($result))
{
echo "Student Number: $row[username]<br>Name: $row[namelast]
, $row[namefirst]<br><br> was added to the group<br><br>";
$sn = $row['username'];
$nl = $row['namelast'];
$nf = $row['namefirst'];
$nm = $row['namemi'];
mysql_query("INSERT INTO csci01members (username, namelast, namefirst, namemi)
VALUES ('$sn', '$nl', '$nf', '$nm')");
mysql_close($con);
}
}
}
$con = mysql_connect("localhost","root","");
if(!$con)
{ die("could not connect to server".mysql_error());}
mysql_select_db("login", $con);
$sql="Select * from students";
$sql_result=mysql_query($sql)
or exit("Sql Error".mysql_error());
$sql_num=mysql_num_rows($sql_result);
if($row = mysql_num_rows($sql_result) == 0)
{
echo "There are no registered student yet<br><br>";
$name=$row["username"];
$class=$row["namelast"] .$row["namefirst"];
$accept = "<a href='?add=$row[username]'> </a>";
}
else
{
echo "<table border = 0 width='"200%'">";
echo "<tr>";
echo "<td width = '20%' > <b><center>USN</center></b></td>
<td width = '60%'><b><center>Name</center></b></td>
<td width = '10%'><b><center>Action</center></b></td>";
echo "</tr>";
while($sql_row=mysql_fetch_array($sql_result))
{
$name=$sql_row["username"];
$class=$sql_row["namelast"] . ', '.$sql_row["namefirst"];
$accept = "<a href='?add=$sql_row[username]'>[Add]</a>";
echo "<td >".$name."</td>";
echo "<td>".$class."</td>";
echo "<td>".$accept."</td></tr>";
}
}
echo "</table>";
mysql_close();
?>
您的"count_check"计数表中的所有行，您需要添加用户名来计数行
if (empty($errors)){
$check = mysql_query("SELECT * from csci01members WHERE username = '".mysql_real_escape_string($_GET['add'])."'");
$check_count = mysql_num_rows($check);
if ($check_count == 1) {
die (" The user is already a member.");
}
}
对于添加标识符，最好使用数字id。用户名可能包含特殊符号，如空格或其他符号，当您通过url传递它们时，它们被编码为