Difference between revisions of "PHP-and-MySQL/C4/User-Registration-Part-6/English-timed"

|Hello everyone, welcome to this Spoken Tutorial, which is more of an update tutorial and not a full length video.

|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.

|Let us go back to our form which is here. Here you can type your fullname. You can choose a username and a password.

|For example, lets say I'm registering with the username "alex".  In the database we can see here that username "alex" already exists.

|So what we will do is check the existence of the username.  

|Let's just change this for namesake and click register.   

|Let us look inside our database. We can see that we have two usernames with alex.  

|The 1st occurrence of name, this one here will be logged in. And this one will be ignored.  

|So this person really will never be able to login into the database.

|So let's just delete this.  

|You need to create some kind of check to see if the username already exists.

|This is incredibly easy. There are more that one method for doing it.

|Selecting my database. I want to take this up to just where the submit button is checked.  

 

|So, it is just connecting to the database. I am inside here.

|Then, under here I can start my code to check my username.  

 

|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.

|If the username has been found, I can put it in anywhere.  

|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.

|I recommend casing the checks that you already have inside the next statement and not really to kill the script.

|We need to just type a query that specifies taking a record with a particular username.

|So I will say "namecheck query" here. I will call the variable "namecheck" and this will be a mysql query.

|I will select "username" for simplicity. This is not going to select all the data.

|So I am selecting username from users,

|since that's our table name here.

|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".

|So we can just come down here and type "username" now.  

|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.  

|Now if I were to specify in this case, with only one record...

|So therefore, the username won't exists, if no records would be returned. So we need a function to check how many records are returned.

|You can do this by creating a count variable. Its "mysql num rows".  

|It just returns the amount of records or rows that are contained within your query which is called "namecheck".

|So lets just test this. I am going to echo out count and then kill the script.  

|Lets go back to register and I'll type my fullname as "alex".  

|Fullname, then choose a username. I am going to choose "Dale".

|But I will just put them there for the sake of it and click Register.   

|That's because "Dale" is not actually in the data base as a username.  

|However if I change this to "alex", that will be a small "a".  

|We have got some... strip tags.  The way to deal with case sensitivity as well, is.... so this is another pointer....

|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.

|Next we are going to... let me find it.... Click Register.  

|We can see that the value of one is returned. .

|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.

|So here we will create a simple if statement and our block.

|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...

|...then we can just kill the script and say "Username already taken" or any other message. Coming back here, lets refresh.

|We can choose "alex". Let me type in a password and click register.  

|You can see that we have got "Username already taken" error.

|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.

|So I will leave it at that. You can see that we have got our registered user in.

| Add a "str to lower" function, which is a really useful thing to keep everything simple.

|Or you can just use a "str to lower" function in your if statement.  

|Thanks for watching. This is Aravind  dubbing for the Spoken Tutorial project.