SQL 按天統計，按月統計和統計天數

確定要統計的時間字段，例句中為start_time

1. 從表TABLE_NAME中以字段START_TIME為參照，按天統計

select START_TIME, DATE_FORMAT(START_TIME,'%Y-%m-%d') as day, count(*) as sum from TABLE_NAME group by day;

2. 從表TABLE_NAME中以字段START_TIME為參照，按月統計

select START_TIME, DATE_FORMAT(START_TIME,'%Y-%m') as month, count(*) as sum from TABLE_NAME group by month;

3. 統計表TABLE_NAME中以字段START_TIME為參照，共多少天數據，多少條數據

select to_days(now()) - to_days(min(START_TIME)) as days, count(*) from TABLE_NAME;