填补数据库返回的日期中的空白

可以通过纯SQL查询完成此操作，还是必须使用某些php逻辑？

是的，最好创建一个Numbers表（单列N），该表只包含数字0到999。它可以用于很多事情，尤其是如下查询：

SELECt COUNT(t.click_date) as clicks,    DATE_FORMAT(adddate($start_date, interval N day), '%d %M %Y') as point FROM NumbersLEFT JOIN tracking t    ON t.click_date >= adddate($start_date, interval N day)    and t.click_date < adddate($start_date, interval (N+1) day)WHERe N between 0 and datediff($start_date, $end_date)GROUP BY N

顺便说一句，为什么我将2011年2月0日作为第一次约会

您使用的格式错误。W的大写W在一周中的某天不降低，因此对于月中的 ‘％W％M％Y’ 或 ‘％d％M％Y’ 。
http://dev.mysql.com/doc/refman/5.5/zh-CN/date-and-time-
functions.html#function_date-
format

也许我的GROUP BY无法正常工作？

您使用的

GROUP BY DAY(FROM_UNIXTIME(click_date))

编辑： 如果您不希望具体化（创建为真实表）数字序列表，则可以动态构建一个。不会很漂亮

注意：下面的N1，N2和N3组合起来可能会产生0-999的范围

SELECt COUNT(t.click_date) as clicks,    DATE_FORMAT(adddate($start_date, interval N day), '%d %M %Y') as point FROM (    select N1 * 100 + N2 * 10 + N3 as N    from (    select 0 N1 union all select 1 union all select 2 union all    select 3 union all select 4 union all select 5 union all    select 6 union all select 7 union all    select 8 union all select 9) N1    cross join (    select 0 N2 union all select 1 union all select 2 union all    select 3 union all select 4 union all select 5 union all    select 6 union all select 7 union all    select 8 union all select 9) N2    cross join (    select 0 N3 union all select 1 union all select 2 union all    select 3 union all select 4 union all select 5 union all    select 6 union all select 7 union all    select 8 union all select 9) N3    ) NumbersLEFT JOIN tracking t    ON t.click_date >= adddate($start_date, interval N day)    and t.click_date < adddate($start_date, interval (N+1) day)WHERe N between 0 and datediff($start_date, $end_date)GROUP BY N

编辑＃2： 一个直接的日期表

将其放在phpMyAdmin的新窗口中或批量运行。它创建一个名为Dates的表，其中每个日期都是从天

1900-01-01

2300-01-01

DROP PROCEDURE IF EXISTS FillDateTable;delimiter //CREATE PROCEDURE FillDateTable()    LANGUAGE SQL    NOT DETERMINISTIC    ConTAINS SQL    SQL SECURITY DEFINER    COMMENT ''BEGIN  drop table if exists datetable;  create table datetable (thedate datetime primary key, isweekday smallint);  SET @x := date('1900-01-01');  REPEAT     insert into datetable (thedate, isweekday) SELECT @x, case when dayofweek(@x) in (1,7) then 0 else 1 end;    SET @x := date_add(@x, interval 1 day);    UNTIL @x > date('2300-01-01') END REPEAT;END//delimiter ;CALL FillDateTable;

有了这样的实用程序表，您的查询就可以

SELECT COUNT(t.click_date) as clicks,    DATE_FORMAT(thedate, '%d %M %Y') as point FROM DatesLEFT JOIN tracking t    ON t.click_date >= thedate    and t.click_date < adddate(thedate, interval 1 day)WHERe thedate between $start_date and $end_dateGROUP BY thedate