MySQL YEARWEEK（）関数

日付の年と週の番号を返します。

SELECT YEARWEEK("2017-06-15");

定義と使用法

YEARWEEK（）関数は、指定された日付の年と週の数値（0から53までの数値）を返します。

YEARWEEK(date, firstdayofweek)

Parameter	Description
date	Required. The date or datetime value to extract the year and week number from
firstdayofweek	Optional. Specifies what day the week starts on. Can be one of the following: 0 - First day of week is Sunday 1 - First day of week is Monday and the first week has more than 3 days 2 - First day of week is Sunday 3 - First day of week is Monday and the first week has more than 3 days 4 - First day of week is Sunday and the first week has more than 3 days 5 - First day of week is Monday 6 - First day of week is Sunday and the first week has more than 3 days 7 - First day of week is Monday

Parameter

Description

date

Required. The date or datetime value to extract the year and week number from

firstdayofweek

Optional. Specifies what day the week starts on. Can be one of the following:

で動作します：	MySQL4.0から

日付の年と週の番号を返します。

SELECT YEARWEEK("2017-10-25");

現在のシステム日付の年と週の番号を返します。

SELECT YEARWEEK(CURDATE());