ใช้ตัวดำเนินการตรรกะ AND, OR, NOT ในการสร้าง MySQL View

ตัวดำเนินการตรรกะใน View

1. AND Operator

คืน TRUE ถ้าทั้งสองเงื่อนไขจริง

mysql> CREATE OR REPLACE VIEW Info AS 
    -> SELECT ID, Name, Address, Subject 
    -> FROM Student_info 
    -> WHERE Subject = 'Computers' AND Address = 'DELHI';
Query OK, 0 rows affected (0.13 sec)

mysql> SELECT * FROM Info;
+------+-------+---------+-----------+
| ID   | Name  | Address | Subject   |
+------+-------+---------+-----------+
|  133 | Mohan | Delhi   | Computers |
+------+-------+---------+-----------+

2. OR Operator

คืน TRUE ถ้าอย่างน้อยหนึ่งเงื่อนไขจริง

mysql> CREATE OR REPLACE VIEW Info AS 
    -> SELECT ID, Name, Address, Subject 
    -> FROM Student_info 
    -> WHERE Subject = 'Computers' OR Address = 'Amritsar';
Query OK, 0 rows affected (0.06 sec)

mysql> SELECT * FROM Info;
+------+---------+----------+-----------+
| ID   | Name    | Address  | Subject   |
+------+---------+----------+-----------+
|  101 | YashPal | Amritsar | History   |
|  125 | Raman   | Shimla   | Computers |
|  130 | Ram     | Jhansi   | Computers |
|  133 | Mohan   | Delhi    | Computers |
+------+---------+----------+-----------+

3. NOT Operator

คืน TRUE ถ้าเงื่อนไขเท็จ (ใช้ != หรือ NOT)

mysql> CREATE OR REPLACE VIEW Info AS 
    -> SELECT ID, Name, Address, Subject 
    -> FROM Student_info 
    -> WHERE Subject != 'Computers';
Query OK, 0 rows affected (0.06 sec)

mysql> SELECT * FROM Info;
+------+---------+------------+------------+
| ID   | Name    | Address    | Subject    |
+------+---------+------------+------------+
|  101 | YashPal | Amritsar   | History    |
|  105 | Gaurav  | Chandigarh | Literature |
|  132 | Shyam   | Chandigarh | Economics  |
+------+---------+------------+------------+

แสดงเฉพาะ Subject ที่ไม่ใช่ Computers