खैर, निम्नलिखित पर विचार करें...
DROP TABLE IF EXISTS abc;
CREATE TABLE abc
(id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
,ColA CHAR(1) NOT NULL
,ColB CHAR(3) NOT NULL
,ColC INT NOT NULL
);
INSERT INTO abc (ColA,ColB,ColC) VALUES
('A','xxx',40),
('A','YYY',40),
('A','zzz',40),
('B','ABC',50),
('B','BCA',50),
('C','TTT',60),
('C','FFF',60);
SELECT * FROM abc;
+----+------+------+------+
| id | ColA | ColB | ColC |
+----+------+------+------+
| 1 | A | xxx | 40 |
| 2 | A | YYY | 40 |
| 3 | A | zzz | 40 |
| 4 | B | ABC | 50 |
| 5 | B | BCA | 50 |
| 6 | C | TTT | 60 |
| 7 | C | FFF | 60 |
+----+------+------+------+
SELECT id,a,b,c
FROM (
SELECT id
, CASE WHEN ColA = @prev_a
THEN @curr_a:= ''
ELSE @curr_a := ColA END a
, @prev_a := ColA
, CASE WHEN ColB = @prev_b
THEN @curr_b:= ''
ELSE @curr_b := ColB END b
, @prev_b := ColB
, CASE WHEN ColC = @prev_c
THEN @curr_c:= ''
ELSE @curr_c := ColC END c
, @prev_c := ColC
FROM abc
, (SELECT @curr_a = ''
, @prev_a = ''
, @curr_b = ''
, @prev_b = ''
, @curr_c = ''
, @prev_c = ''
) vars
ORDER
BY id
) x ORDER BY id;
+----+------+------+------+
| id | a | b | c |
+----+------+------+------+
| 1 | A | xxx | 40 |
| 2 | | YYY | |
| 3 | | zzz | |
| 4 | B | ABC | 50 |
| 5 | | BCA | |
| 6 | C | TTT | 60 |
| 7 | | FFF | |
+----+------+------+------+
मुझे यह उल्लेख करना चाहिए कि यह कोलाज मैच मानता है (जैसे SET NAMES utf8;)
