我如何修复weekofyear（'20121231'）返回1？

Question

weekofyear('20121231')返回1，而weekofyear('20121230')返回52

Mysql Ver 5,1,47 Cummunity Nt / Windows 7 32 Bit / ODBC 5.1.10 /
First day of Week : Sunday

它应该返回53但它返回1， week('20121231',1)，week('20121230')在两个案例中都返回53

Answer 1

week需要很多论据，weekofyear只是其中一种形式，与week([date], 3)相同。

阅读manual以查看不同的替代方案。

SQLFiddle

Answer 2

根据documentation，weekofyear('20121231') 不等同于week('20121231',1)：

  

WEEKOFYEAR()是兼容性函数，相当于   WEEK(date,3)。

测试它：

mysql> SELECT weekofyear('20121231'), week('20121231',1), week('20121231',3);
+------------------------+--------------------+--------------------+
| weekofyear('20121231') | week('20121231',1) | week('20121231',3) |
+------------------------+--------------------+--------------------+
|                      1 |                 53 |                  1 |
+------------------------+--------------------+--------------------+