ULUwiVY4

1select * from table where timestamp BETWEEN '2018-01-10 00:00:00' AND '2018-01-11 23:59:59
2
3id timestamp            product
41  10-1-2018:10:02:02   a
52  10-1-2018:10:02:03   b
63  11-1-2018:10:02:05   a
74  11-1-2018:10:02:09   b
85  11-1-2018:10:02:19   a
96  11-1-2018:10:02:23   b
10	
11id timestamp            product
121  10-1-2018:10:02:02   a
132  10-1-2018:10:02:03   b
145  11-1-2018:10:02:19   a
156  11-1-2018:10:02:23   b
16	
17DROP TABLE IF EXISTS my_table;
18
19CREATE TABLE my_table
20(id SERIAL PRIMARY KEY
21,timestamp DATETIME NOT NULL
22,product CHAR(1) NOT NULL
23);
24
25INSERT INTO my_table VALUES
26(1,'2018-01-10:10:02:02','a'),
27(2,'2018-01-10:10:02:03','b'),
28(3,'2018-01-11:10:02:05','a'),
29(4,'2018-01-11:10:02:09','b'),
30(5,'2018-01-11:10:02:19','a'),
31(6,'2018-01-11:10:02:23','b');
32
33SELECT a.* 
34  FROM my_table a 
35  JOIN 
36     ( SELECT product
37            , MAX(timestamp) timestamp 
38         FROM my_table 
39        GROUP 
40           BY product
41            , DATE(timestamp)
42     ) b 
43    ON b.product = a.product 
44   AND b.timestamp = a.timestamp;
45+----+---------------------+---------+
46| id | timestamp           | product |
47+----+---------------------+---------+
48|  1 | 2018-01-10 10:02:02 | a       |
49|  2 | 2018-01-10 10:02:03 | b       |
50|  5 | 2018-01-11 10:02:19 | a       |
51|  6 | 2018-01-11 10:02:23 | b       |
52+----+---------------------+---------+