CREATE TABLE ajatood(
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  algus DATETIME,
  ots DATETIME,
  tasu DECIMAL(8, 2)
);


INSERT INTO ajatood VALUES(DEFAULT, '2015-12-1 8:15', '2015-12-1 12:45', 25);
INSERT INTO ajatood VALUES(DEFAULT, '2015-12-1 8:15', '2015-12-1 18:45', 45);
INSERT INTO ajatood VALUES(DEFAULT, '2015-12-1 8:15', '2015-12-1 13:45', 15);
SELECT *, tasu/TIMESTAMPDIFF(HOUR, algus, ots) AS tunnitasu FROM ajatood;

SELECT *, tasu/TIMESTAMPDIFF(HOUR, algus, ots) AS tunnitasu FROM ajatood
  ORDER BY tunnitasu;

SELECT * FROM ajatood WHERE HOUR(ots)>17;

SELECT *, IF(HOUR(ots)>17, 'yletund', 'tavaline') AS aeg FROM ajatood;

SELECT if(DAYOFWEEK(NOW())>1, DAYOFWEEK(NOW())-1, 7);