Create table with date column - mysql

Question

I want to create a student table with column 'student_birthday' and its format should be dd-mm-yy.
create table `student`.`studentinfo`(
`student_id` int(10) not null auto_increment,
`student_name` varchar(45) not null,
`student_surname` varchar(45) not null,
`student_birthday` date(???),
(some lines of code)
primary key(student_id));
what should be inputted in the (???) to get the right format above?

Answer 1

Just use "DATE" without the brackets. The brackets are only needed for certain column types where you want to specify the maximum number of bytes/characters that can be stored.
For MySQL, it's documented at https://dev.mysql.com/doc/refman/5.7/en/date-and-time-types.html

Answer 2

The following example will explain your problem. I am using MySQL 5.7.18.
Firstly I have described the structure of users table as I am going to create posts table with FOREIGN KEY.
Later I created posts table and it has a DATE field named created with many other columns.
Finally I inserted 1 row in the newly created table.
mysql> desc users;
+-------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| id | bigint(20) | NO | PRI | NULL | |
| fname | varchar(50) | NO | | NULL | |
| lname | varchar(50) | NO | | NULL | |
| uname | varchar(20) | NO | | NULL | |
| email | text | NO | | NULL | |
| contact | bigint(12) | NO | | NULL | |
| profile_pic | text | NO | | NULL | |
+-------------+-------------+------+-----+---------+-------+
7 rows in set (0.00 sec)
mysql> CREATE TABLE posts(id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY, title text NOT NULL, description text NOT NULL, posted_by bigint, FOREIGN KEY(posted_by) REFERENCES users(id) ON DELETE CASCADE ON UPDATE RESTRICT , created DATE);
Query OK, 0 rows affected (0.01 sec)
mysql> desc posts;
+-------------+------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+------------+------+-----+---------+----------------+
| id | bigint(20) | NO | PRI | NULL | auto_increment |
| title | text | NO | | NULL | |
| description | text | NO | | NULL | |
| posted_by | bigint(20) | YES | MUL | NULL | |
| created | date | YES | | NULL | |
+-------------+------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)
mysql> INSERT INTO posts(title, description, posted_by, created) values("Getting started with MySQL", "Excellent Database system", 1, "2017-05-26");
Query OK, 1 row affected (0.00 sec)
mysql> select * from posts;
+----+----------------------------+---------------------------+-----------+------------+
| id | title | description | posted_by | created |
+----+----------------------------+---------------------------+-----------+------------+
| 1 | Getting started with MySQL | Excellent Database system | 1 | 2017-05-26 |
+----+----------------------------+---------------------------+-----------+------------+
1 row in set (0.00 sec)
mysql>

Answer 3

The datatype date on its own is enough to represent a date value. The format will matter when you are displaying the data, for which you can use the FORMAT function on your date column.
I should add that there is a certain amount of flexibility as to the format when inserting date time literals as documented here.