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MySQL 数据类型 MySQL 函数
字符串函数 ASCII CHAR_LENGTH CHARACTER_LENGTH CONCAT CONCAT_WS FIELD FIND_IN_SET FORMAT INSERT INSTR LCASE LEFT LENGTH LOCATE LOWER LPAD LTRIM MID POSITION REPEAT REPLACE REVERSE RIGHT RPAD RTRIM SPACE STRCMP SUBSTR SUBSTRING SUBSTRING_INDEX TRIM UCASE UPPER 数值函数 ABS ACOS ASIN ATAN ATAN2 AVG CEIL CEILING COS COT COUNT DEGREES DIV EXP FLOOR GREATEST LEAST LN LOG LOG10 LOG2 MAX MIN MOD PI POW POWER RADIANS RAND ROUND SIGN SIN SQRT SUM TAN TRUNCATE 日期函数 ADDDATE ADDTIME CURDATE CURRENT_DATE CURRENT_TIME CURRENT_TIMESTAMP CURTIME DATE DATEDIFF DATE_ADD DATE_FORMAT DATE_SUB DAY DAYNAME DAYOFMONTH DAYOFWEEK DAYOFYEAR EXTRACT FROM_DAYS HOUR LAST_DAY LOCALTIME LOCALTIMESTAMP MAKEDATE MAKETIME MICROSECOND MINUTE MONTH MONTHNAME NOW PERIOD_ADD PERIOD_DIFF QUARTER SECOND SEC_TO_TIME STR_TO_DATE SUBDATE SUBTIME SYSDATE TIME TIME_FORMAT TIME_TO_SEC TIMEDIFF TIMESTAMP TO_DAYS WEEK WEEKDAY WEEKOFYEAR YEAR YEARWEEK 高级函数 BIN BINARY CASE CAST COALESCE CONNECTION_ID CONV CONVERT CURRENT_USER DATABASE IF IFNULL ISNULL LAST_INSERT_ID NULLIF SESSION_USER SYSTEM_USER USER VERSION

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MySQL WEEK() 函数

❮ MySQL 函数

示例

返回日期的周数

SELECT WEEK("2017-06-15");
自己尝试 »

定义和用法

WEEK() 函数返回给定日期的周数（从 0 到 53 的数字）。

语法

WEEK(date, firstdayofweek)

参数值

参数 描述
date 必需的。要提取周数的日期或日期时间
firstdayofweek

可选的。指定一周从哪一天开始。可以是以下之一

  • 0 - 一周的第一天是星期日
  • 1 - 星期一的第一个星期，一年中的第一个星期有超过 3 天
  • 2 - 星期日是第一个星期
  • 3 - 星期一的第一个星期，一年中的第一个星期有超过 3 天
  • 4 - 星期日是第一个星期，一年中的第一个星期有超过 3 天
  • 5 - 星期一是第一个星期
  • 6 - 星期日是第一个星期，一年中的第一个星期有超过 3 天
  • 7 - 星期一是第一个星期

技术细节

适用于 从 MySQL 4.0 开始

更多示例

示例

返回日期的周数

SELECT WEEK("2017-10-25");
自己尝试 »

示例

返回当前系统日期的星期数

SELECT WEEK(CURDATE());
自己尝试 »

❮ MySQL 函数

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