MySQL ক্যোয়ারী NULL মান অনুসারে অর্ডার করতে

আসুন প্রথমে একটি টেবিল তৈরি করি -

mysql> create table DemoTable707 (
   StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   StudentFirstName varchar(100),
   StudentMarks int
);
Query OK, 0 rows affected (0.59 sec)

সন্নিবেশ কমান্ড −

mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values('John',45);
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values(NULL,65);
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values('Chris',78);
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values(NULL,89);
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values('Robert',99);
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values(NULL,34);
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable707(StudentFirstName,StudentMarks) values('Mike',43);
Query OK, 1 row affected (0.20 sec)

সিলেক্ট স্টেটমেন্ট -

mysql> select *from DemoTable707;

এটি নিম্নলিখিত আউটপুট তৈরি করবে -

+-----------+------------------+--------------+
| StudentId | StudentFirstName | StudentMarks |
+-----------+------------------+--------------+
| 1         | John             | 45           |
| 2         | NULL             | 65           |
| 3         | Chris            | 78           |
| 4         | NULL             | 89           |
| 5         | Robert           | 99           |
| 6         | NULL             | 34           |
| 7         | Mike             | 43            |
+-----------+------------------+--------------+
7 rows in set (0.00 sec)

NULL মান -

mysql> select *from DemoTable707 order by StudentFirstName IS NULL, StudentFirstName DESC;

এটি নিম্নলিখিত আউটপুট তৈরি করবে -

+-----------+------------------+--------------+
| StudentId | StudentFirstName | StudentMarks |
+-----------+------------------+--------------+
| 5         | Robert           | 99           |
| 7         | Mike             | 43           |
| 1         | John             | 45           |
| 3         | Chris            | 78           |
| 2         | NULL             | 65           |
| 4         | NULL             | 89           |
| 6         | NULL             | 34           |
+-----------+------------------+--------------+
7 rows in set (0.00 sec)