按日期分组日期

Question

I have a problem and can't find a solution.

I have a simple table with TV programs, like this:

CREATE TABLE IF NOT EXISTS programs (
    id_program int NOT NULL AUTO_INCREMENT PRIMARY KEY,
    air datetime, 
    title varchar(50)
);

and some rows in the table:

2003-10-20 17:00    Factor 
2003-10-21 17:00    Factor 
2003-10-22 17:00    Factor
2003-10-20 19:00    Form
2003-10-21 14:00    Factor

How can I obtain the result for Factor, something like this:

monday - wednesday : 17.00
tuesday : 14.00;

Is it possible to do this in SQL or do I need to fetch data in PHP?

Answer 1

I think to get exactly what you want in one query is not easily possible. But I came to something that is nearly your desired result:

SELECT TIME(air), title, GROUP_CONCAT(DAYOFWEEK(air)) 
FROM programs WHERE title = 'Factor' 
GROUP BY TIME(air)

This gives me the following result:

TIME(air)   title   GROUP_CONCAT(DAYOFWEEK(air))
-------------------------------------------------
14:00:00    Factor  3
17:00:00    Factor  2,3,4

With this result you can easily utilize php to get your desired result. Results like "monday, wednesday, friday-saturday" are possible with this too.

Answer 2

select date_format(`air`,'%d-%b %h:%i') from programs

Answer 3

This doesn't answer the question exactly as this is in MSSQL. I know there are MySQL flavors do this though

declare @tempTable TABLE (dt_timeOfProgram datetime, str_name varchar(10));

insert into @tempTable values 
('2003-10-20 17:00', 'Factor'),
('2003-10-21 17:00', 'Factor'),
('2003-10-22 17:00', 'Factor'),
('2003-10-20 19:00', 'Form'),
('2003-10-21 14:00', 'Factor');

select
REPLACE(REPLACE(REPLACE(dow, '</dow><dow>', ','), '<dow>',''),'</dow>', '') as DOW
,   [time]
,   [showName]
from (  select distinct
        CAST(dt_timeOfProgram as time) as [time], 
        str_name [showName],
        (   SELECT DATENAME(dw, t1.dt_timeOfProgram) as [dow]
            FROM @tempTable t1 
            where t1.str_name=t2.str_name
            and  CAST(t1.dt_timeOfProgram as time) = CAST(t2.dt_timeOfProgram as time)
            order by t1.dt_timeOfProgram
            for XML PATH('')) [dow]
    from @tempTable t2) as t

And here is the resultset

Tuesday                     14:00:00.0000000    Factor
Monday,Tuesday,Wednesday    17:00:00.0000000    Factor
Monday                      19:00:00.0000000    Form

This is pretty sloppy work though. I would never do this in a live application. This logic would be handled by business logic instead of db.

Database resources in general are the LEASE scalable. So in the end, you want to use them as little as possible.

Good Luck