how to register unique data into my table using php?
i have the following table.
create table tbuser
(username varchar(50) unique,
password varchar(255))
then again i hv the following html code register.php
Code:
<html>
<body>
register now<p>
<table width="300" border="0" align="center" cellpadding="0" cellspacing="1">
<tr>
<td><form name="form1" method="post" action="insert_ac.php">
<table width="100%" border="0" cellspacing="1" cellpadding="3">
<tr>
<td colspan="3"><strong>Insert Data Into mySQL Database </strong></td>
</tr>
<tr>
<td width="71">Name</td>
<td width="6">:</td>
<td width="301"><input name="username" type="text" id="username"></td>
</tr>
<tr>
<td>Lastname</td>
<td>:</td>
<td><input name="password" type="password" id="password"></td>
</tr>
<tr>
<td>Email</td>
<td>:</td>
</tr>
<tr>
<td colspan="3" align="center"><input type="submit" name="Submit" value="Submit"></td>
</tr>
</table>
</form>
</td>
</tr>
</table>
</body>
and the insert_ac.php is as follow.
Code:
<?php
$host="localhost"; // Host name
$username="root"; // Mysql username
$password=""; // Mysql password
$db_name="test"; // Database name
$tbl_name="users"; // Table name
// Connect to server and select database.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");
// Get values from form
$username=$_POST['username'];
$password=$_POST['password'];
// Insert data into mysql
$sql="INSERT INTO $tbl_name(username, password)VALUES('$username', '$password')";
$result=mysql_query($sql);
// if successfully insert data into database, displays message "Successful".
if($result){
echo "Successful";
echo "<BR>";
echo "<a href='insert.php'>Back to main page</a>";
}
else {
echo "ERROR";
}
// close connection
mysql_close();
?>
now this code inserts data seccessfuly, but i want to make sure that evey user must have unique USERNAME,
i register using username=testuser and password with="test"
then if someone tries to register using my username which is already in the databas, there must be an error message that indicates him, the username is already taken, try an other username.
so how can i code this?thanks
Re: how to register unique data into my table using php?
you need to make a quick SQL query before inserting to check if that user exists.
PHP Code:
$sql = "SELECT username FROM $tbl_name WHERE username='{$_POST['username']}'";
$namecheck = mysql_query($sql);
if(mysql_num_rows($namecheck) > 0){
echo "this name already exists.";
}else{
echo "this name does not exist.";
}
