如果你想要纯粹的SQL:
SELECT COUNT(*)
FROM [table_name]
WHERE birth_date < DATE_ADD(NOW(),INTERVAL 13 YEAR)
WHERE birth_date >= DATE_ADD(NOW(),INTERVAL 13 YEAR)
AND birth_date < DATE_ADD(NOW(),INTERVAL 15 YEAR)
否则我建议使用PHP来创建日期。
您可以将所有查询联合在一起并创建SQL视图,例如:
CREATE VIEW statistics AS
SELECT "0-13" as age ,COUNT(*) as total
FROM table_name
WHERE birth_date < DATE_ADD(NOW(),INTERVAL 13 YEAR)
UNION
SELECT "13-15" as age ,COUNT(*) as total
FROM table_name
WHERE birth_date >= DATE_ADD(NOW(),INTERVAL 13 YEAR)
AND birth_date < DATE_ADD(NOW(),INTERVAL 15 YEAR)
UNION
SELECT "15-20" as age ,COUNT(*) as total
FROM table_name
WHERE birth_date >= DATE_ADD(NOW(),INTERVAL 15 YEAR)
AND birth_date < DATE_ADD(NOW(),INTERVAL 20 YEAR)
UNION
SELECT "20-23" as age ,COUNT(*) as total
FROM table_name
WHERE birth_date >= DATE_ADD(NOW(),INTERVAL 20 YEAR)
AND birth_date < DATE_ADD(NOW(),INTERVAL 23 YEAR)
UNION
SELECT "23+" as age ,COUNT(*) as total
FROM table_name
WHERE birth_date >= DATE_ADD(NOW(),INTERVAL 23 YEAR)
然后您只需查询:
SELECT * from statistics