MySQLでn日後・n日前の時間を取得する方法

結論
mysql> select now() + INTERVAL 1 DAY;
+------------------------+
| now() + INTERVAL 1 DAY |
+------------------------+
| 2020-07-08 16:13:32    |
+------------------------+
1 row in set (0.00 sec)
mysql> select now() - INTERVAL 1 DAY;
+------------------------+
| now() - INTERVAL 1 DAY |
+------------------------+
| 2020-07-06 16:14:51    |
+------------------------+
1 row in set (0.00 sec)
INTERVAL構文でできます。簡単ですね。
ちなみにDAYだけではなく、下記のunit(単位)であれば指定可能らしいです。
unit 値 | 要求される expr 書式 | 
|---|---|
MICROSECOND | MICROSECONDS | 
SECOND | SECONDS | 
MINUTE | MINUTES | 
HOUR | HOURS | 
DAY | DAYS | 
WEEK | WEEKS | 
MONTH | MONTHS | 
QUARTER | QUARTERS | 
YEAR | YEARS | 
SECOND_MICROSECOND | 'SECONDS.MICROSECONDS' | 
MINUTE_MICROSECOND | 'MINUTES:SECONDS.MICROSECONDS' | 
MINUTE_SECOND | 'MINUTES:SECONDS' | 
HOUR_MICROSECOND | 'HOURS:MINUTES:SECONDS.MICROSECONDS' | 
HOUR_SECOND | 'HOURS:MINUTES:SECONDS' | 
HOUR_MINUTE | 'HOURS:MINUTES' | 
DAY_MICROSECOND | 'DAYS HOURS:MINUTES:SECONDS.MICROSECONDS' | 
DAY_SECOND | 'DAYS HOURS:MINUTES:SECONDS' | 
DAY_MINUTE | 'DAYS HOURS:MINUTES' | 
DAY_HOUR | 'DAYS HOURS' | 
YEAR_MONTH | 'YEARS-MONTHS' | 
バージョン
$ mysql --version
mysql  Ver 14.14 Distrib 5.7.30, for Linux (x86_64) using  EditLine wrapper
	




