PHP-and-MySQL/C4/User-Registration-Part-6/English-timed

Time	Narration
00:00	Hello everyone, welcome to this Spoken Tutorial which is more of an update tutorial and not a full length video.
00:08	Some one has pointed out to me that in my register script, I need some kind of check to note if the user has been registered or not by the "username" that they specify.
00:19	Let us go back to our form which is here. Here you can type your 'full name'. You can choose a 'username' and a 'password'.
00:28	I have had these values here before. Let us get rid of them for now.
00:33	But, what we want is, when we are choosing the username...
00:37	for example, let's say I'm registering with the username "alex". In the database we can see here that the username "alex" already exists.
00:47	So, what we will do is check the existence of the username.
00:50	If the username already exists, we are not going to let the user register because we don't want a double username.
01:01	If I were to register here, let me put the password in and choose the username as "alex". The username "alex" is already in the database.
01:13	Let's change this for namesake and click Register.
01:20	I have been successfully registered.
01:23	Let us look inside our database. We can see that we have two usernames with "alex".
01:28	Now this causes problems while logging in.
01:31	The 1st occurrence of name, this one here will be logged in and this one will be ignored.
01:39	So, this person really will never be able to login into the database.
01:44	So, let's just delete this.
01:48	You need to create some kind of check to see if the 'username' already exists.
01:53	This is incredibly easy. There are more than one method for doing it.
01:59	But I am going for the simplest and probably the most effective way which is going to work.
02:05	The first thing I want to do is, take my code to connect to my database.
02:12	Selecting my database, I want to take this up to just where the 'submit' button is checked.
02:20	So, this is just connecting to the database. I am inside here.
02:26	Then, under here I can start my code to check my 'username'.
02:31	Now, you can't put your check anywhere. For simplicity, I am just going to put it here and kill the rest of the script.
02:39	If the 'username' has been found, I can put it in anywhere.
02:44	Take care when you are using a full length page in your website, the die function will cut off the rest of the code. So I don't recommend using this.
02:53	I recommend casing the checks that you already have inside the next statement and not really to kill the script.
03:00	But you will get the general idea here on how to work on what we are trying to do.
03:06	We need to just type a query that specifies taking a record with a particular username.
03:12	So, I will say "namecheck query" here. I will call the variable "$namecheck" and this will be a mysql query.
03:21	I will select "username" for simplicity. This is not going to select all the data.
03:27	So, I am selecting username from "users"
03:35	since that's our table name here.
03:39	I am going to say "WHERE username" is equal to... If we look up here, username of the person that submits the form is in the variable name "username".
03:50	So, we can just come down here and type "username" now.
03:55	Now if we choose the name "alex", this would select every record in the database that has the username "alex" and we can see there's one at the moment.
04:09	Now if I were to specify in this case, with only one record.
04:15	If I were to specify the username as "Dale", for example, no records will be returned.
04:20	So therefore, the username won't exist, if no records would be returned. So we need a function to check how many records are returned.
04:29	You can do this by creating a $count variable. It's "mysql num rows".
04:36	It just returns the amount of records or rows that are contained within your query which is called "$namecheck".
04:47	So, let's just test this. I am going to echo out $count and then kill the script.
04:53	The rest of the code does not execute.
04:57	Let's go back to Register and I'll type my full name as "alex".
05:03	Fullname, then choose an username. I am going to choose "Dale".
05:10	The password won't be checked so we could skip that.
05:16	But I will just put them here for the sake of it and click Register.
05:24	We see that we have got a value of zero that is returned.
05:28	That's because "Dale" is not actually in the database as a 'username'.
05:32	However, if I change this to "alex", that will be a small "a".
05:39	We have got some strip tags. The way to deal with case sensitivity as well, is.... so, this is another pointer..
05:49	When we are taking the 'username' into account, what we are going to say "string to lower" here, just to make sure that this will always convert to lowercase.
06:01	Next we are going to... let me find it.... Click Register.
06:08	We can see that the value of one is returned.
06:12	So, the check that we were looking for here is - if this variable we are echoing out, is not equal to zero,..then we need to tell the user that the username is already registered.
06:25	So, here we can create a simple if statement and our block.
06:29	Then we can say, if our '$count' doesn't equal zero, meaning there is a record present under this condition where the 'username' is already specified...
06:40	...then we can just kill the script and say "Username already taken!" or any other message. Coming back here, let's refresh.
06:50	We can choose "alex". Let me type in a password and click Register.
06:56	You can see that we have got "Username already taken!" error.
07:00	If I was to type "Dale" and choose a new name and password and click Register, we can see that it has been successfully registered into the database because the 'username' does not exists.
07:15	So, I will leave it at that. You can see that we have got our registered user in.
07:22	Add a "str to lower" function which is a really useful thing to keep everything simple.
07:29	Or you can just use a "str to lower" function in your if statement.
07:32	However, to keep it simple I would recommend that you convert all usernames into lowercase.
07:39	You need to incorporate that into a login script as well. You need to convert whatever the user is typing into the login box to lowercase.
07:48	I encourage you to play around with it. That's a good way to find some errors.
07:53	Try them but if you do need any help, please email me. Make sure you subscribe for updates.
07:58	Thanks for watching. This is Aravind, dubbing for the Spoken Tutorial project.

Contributors and Content Editors

Gaurav, Gyan, PoojaMoolya, Pratik kamble, Sandhya.np14