Question

I am trying to implement NOT NULL constraint in the customer table which is created as:

CREATE TABLE CUSTOMER(
     cust_id INT(5) NOT NULL AUTO_INCREMENT, 
     PRIMARY KEY(cust_id),
     first_name VARCHAR(25) NOT NULL,
     last_name VARCHAR(25) NOT NULL,
     email VARCHAR(25) NOT NULL,
     password VARCHAR(25) NOT NULL,
     gender VARCHAR(1) NOT NULL,
     city VARCHAR(25) NOT NULL,
     dob DATE NOT NULL,
     pin INT NOT NULL);

After this from a form i am passing values and inserting it as :

$sql= "INSERT INTO customer(first_name,last_name,email,password,gender,city,dob,pin) VALUES('$first_name','$last_name','$email_add','$password','$gender','$city','$DOB','$pin')";

However if i am passing blank values of the fields,Mysql seems to insert them? What can be the possible problem??

Answer 1

$sql= "INSERT INTO customer(first_name,last_name,email,password,gender,city,dob,pin) VALUES('$first_name',".
($last_name?"'".$last_name."'":"NULL").
", '$email_add','$password','$gender','$city','$DOB','$pin')";

This will be:

VALUES('ahm',NULL,'[e-mail]' ...

And because of NOT NULL nothing will be inserted.