MySQL में CASE स्टेटमेंट के साथ OR शर्त का उपयोग

CASE एक्सप्रेशन में OR शर्त का उपयोग करके एकाधिक मानों के लिए समान परिणाम दे सकते हैं।

सिंटैक्स:

SELECT col1,
       CASE WHEN col2 = 0 OR col2 IS NULL THEN 'Message1' ELSE 'Message2' END AS alias
FROM yourTable;

एक टेबल बनाते हैं:

CREATE TABLE ReservationSystems (
    Id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
    Name VARCHAR(20),
    isSeatConfirmed TINYINT
);

रिकॉर्ड डालें:

INSERT INTO ReservationSystems (Name, isSeatConfirmed) VALUES ('Larry', 0);
INSERT INTO ReservationSystems (Name, isSeatConfirmed) VALUES ('Bob', 1);
INSERT INTO ReservationSystems (Name, isSeatConfirmed) VALUES ('Mike', NULL);
INSERT INTO ReservationSystems (Name, isSeatConfirmed) VALUES ('David', 1);
INSERT INTO ReservationSystems (Name, isSeatConfirmed) VALUES ('Carol', 0);
INSERT INTO ReservationSystems (Name, isSeatConfirmed) VALUES ('James', 1);

सभी रिकॉर्ड देखें:

SELECT * FROM ReservationSystems;

आउटपुट

+----+-------+-----------------+
| Id | Name  | isSeatConfirmed |
+----+-------+-----------------+
| 1  | Larry | 0               |
| 2  | Bob   | 1               |
| 3  | Mike  | NULL            |
| 4  | David | 1               |
| 5  | Carol | 0               |
| 6  | James | 1               |
+----+-------+-----------------+

CASE के साथ OR शर्त:

SELECT Name,
       CASE WHEN isSeatConfirmed = 0 OR isSeatConfirmed IS NULL
            THEN 'YOUR SEAT IS NOT CONFIRMED'
            ELSE 'YOUR SEAT IS CONFIRMED'
       END AS SEATCONFIRMSTATUS
FROM ReservationSystems;

आउटपुट

+-------+----------------------------+
| Name  | SEATCONFIRMSTATUS          |
+-------+----------------------------+
| Larry | YOUR SEAT IS NOT CONFIRMED |
| Bob   | YOUR SEAT IS CONFIRMED     |
| Mike  | YOUR SEAT IS NOT CONFIRMED |
| David | YOUR SEAT IS CONFIRMED     |
| Carol | YOUR SEAT IS NOT CONFIRMED |
| James | YOUR SEAT IS CONFIRMED     |
+-------+----------------------------+

नोट: NULL की तुलना = से नहीं की जा सकती, इसलिए IS NULL आवश्यक है।