在mysql中添加公式

Question

I want create a new table from the existing table.

This is existing table

A       B               C     
title   view_count  date   

aaa      24      5/18/13    
bbb      10      5/18/13    
ccc      10      5/18/13    
aaa      10      5/19/13    
aaa      20      5/20/13    
bbb      10      5/20/13    
ccc      20      5/20/13    
ccc      20      5/21/13    
aaa       5      5/22/13    
bbb       3      5/22/13    
ccc       1      5/22/13    

I try to make new table as follows:

title  date1(5/18/13)    date2(5/19/13)    date3(5/20/13)

aaa      24 (view_count)      10                20

How can I make this in MySQL?

======================= I add my question. I've tried these queries you help, and then I got results what I want. Can I make them as a new table? I want to make a new table as these results.

Answer 1

EDIT...OP changed his question while I was answering it,

SUMIFS() Can Help!

I use this a lot as I lookup and return data all day. It allows you to return a value from a range where a one or more certain criteria from a range is true. Works great with data structured like yours.

If your headers in row 1 are as shown with the data in row 2 and Your Today date is in F1, then the formula you can type in column D2 and drag down would be...

=(SUMIFS(B:B,A:A,A2,C:C,$F$1-1)-SUMIFS(B:B,A:A,A2,C:C,$F$1-2))/(SUMIFS(B:B,A:A,A2,C:C,$F$1-1))

You can change the value of cell F1 with the excel function Today() and or just put Today into your formula.

I hope this helps.

-Schebealls

Answer 2

You can do this like so:

select title,
       sum(case `date` when '2013/05/18' then view_count else 0 end) `date1(5/18/13)`,
       sum(case `date` when '2013/05/19' then view_count else 0 end) `date2(5/19/13)`,
       sum(case `date` when '2013/05/20' then view_count else 0 end) `date3(5/20/13)`
from myTable
group by title

- to return values for all titles; if you only want to see results for title aaa, then replace group by title with where title='aaa' .

Answer 3

Try this Query

select 
    distinct
    t.title,
    t1.view_count as `date1(5/18/13)`,
    t2.view_count as `date2(5/19/13)`,
    t3.view_count as `date2(5/20/13)`
from table_name t
left join table_name t1 on t.title=t1.title and t1.date='2013/5/18'
left join table_name t2 on t.title=t2.title and t2.date='2013/5/19'
left join table_name t3 on t.title=t3.title and t3.date='2013/5/20'
where t.title='aaa'

SQL Fiddle