您需要注意，年份周处于预期的模式". (请参见 https://dev.mysql .com/doc/refman/5.7/en/date-and-time-functions.html#function_week )

You need to be careful that the yearweek is in the expected "mode". (See https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_week)

STR_TO_DATE中使用的格式应匹配. (请参见 https://dev .mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-format )

The formatting used in the STR_TO_DATE should match. (See https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-format)

例如如果使用模式2(1-53，则第1周是其中包含星期日的第一周，几周从星期日开始)

e.g. If using mode 2 (1-53, Week 1 is the first week with a Sunday in it, weeks start on a Sunday)

SELECT STR_TO_DATE(CONCAT('201439',' Sunday'), '%X%V %W');

例如如果使用模式3(遵循ISO-8601)(1-53，第1周是具有4天或更多天的第一周，从星期一开始)，则需要使用小写版本.

e.g. If using mode 3 (following ISO-8601), (1-53, Week 1 is the first week with 4 or more days, starting on a Monday), you need to use the lower-case version.

SELECT STR_TO_DATE(CONCAT('201439',' Monday'), '%x%v %W');

因此，您将获得以下信息(2014-09-28是星期日):

So, one would get the following (2014-09-28 is a Sunday):

SELECT yearweek('2014-09-28', 2);
201439
SELECT yearweek('2014-09-28', 3);
201439
SELECT yearweek('2014-09-29', 2);
201439
SELECT yearweek('2014-09-29', 3);
201440

然后

SELECT STR_TO_DATE(CONCAT('201439',' Sunday'), '%X%V %W'); -- mode 2
2014-09-28
SELECT STR_TO_DATE(CONCAT('201439',' Monday'), '%x%v %W'); -- mode 3 
2014-09-22
SELECT STR_TO_DATE(CONCAT('201440',' Monday'), '%x%v %W'); -- mode 3
2014-09-29