I am trying to select only today\'s records from a database table.
Currently I use
SELECT * FROM `table` WHERE (`timestamp` > DATE_SUB(now(), INTE
This could be the easiest in my opinion:
SELECT * FROM `table` WHERE `timestamp` like concat(CURDATE(),'%');
If you want an index to be used and the query not to do a table scan:
WHERE timestamp >= CURDATE()
AND timestamp < CURDATE() + INTERVAL 1 DAY
To show the difference that this makes on the actual execution plans, we'll test with an SQL-Fiddle (an extremely helpful site):
CREATE TABLE test --- simple table
( id INT NOT NULL AUTO_INCREMENT
,`timestamp` datetime --- index timestamp
, data VARCHAR(100) NOT NULL
DEFAULT 'Sample data'
, PRIMARY KEY (id)
, INDEX t_IX (`timestamp`, id)
) ;
INSERT INTO test
(`timestamp`)
VALUES
('2013-02-08 00:01:12'),
--- --- insert about 7k rows
('2013-02-08 20:01:12') ;
Lets try the 2 versions now.
Version 1 with DATE(timestamp) = ?
EXPLAIN
SELECT * FROM test
WHERE DATE(timestamp) = CURDATE() --- using DATE(timestamp)
ORDER BY timestamp ;
Explain:
ID SELECT_TYPE TABLE TYPE POSSIBLE_KEYS KEY KEY_LEN REF
1 SIMPLE test ALL
ROWS FILTERED EXTRA
6671 100 Using where; Using filesort
It filters all (6671) rows and then does a filesort (that's not a problem as the returned rows are few)
Version 2 with timestamp <= ? AND timestamp < ?
EXPLAIN
SELECT * FROM test
WHERE timestamp >= CURDATE()
AND timestamp < CURDATE() + INTERVAL 1 DAY
ORDER BY timestamp ;
Explain:
ID SELECT_TYPE TABLE TYPE POSSIBLE_KEYS KEY KEY_LEN REF
1 SIMPLE test range t_IX t_IX 9
ROWS FILTERED EXTRA
2 100 Using where
It uses a range scan on the index, and then reads only the corresponding rows from the table.
How many ways can we skin this cat? Here is yet another variant.
SELECT * FROM table
WHERE DATE(FROM_UNIXTIME(timestamp
)) = '2015-11-18';
If you want to compare with a particular date , You can directly write it like :
select * from `table_name` where timestamp >= '2018-07-07';
// here the timestamp is the name of the column having type as timestamp
or
For fetching today date , CURDATE() function is available , so :
select * from `table_name` where timestamp >= CURDATE();
use DATE
and CURDATE()
SELECT * FROM `table` WHERE DATE(`timestamp`) = CURDATE()
I guess using DATE
still uses INDEX.
see the execution plan on the DEMO
Or you could use the CURRENT_DATE alternative, with the same result:
SELECT * FROM yourtable WHERE created >= CURRENT_DATE
Examples from database.guide