MYSQL sorting based on provided month - php

Question

I have two tables with given structure :
Table 1:
ST_Id ST_Name
1 xx
2 yy
Table 2 :
AT_Id AT_Amt ST_ID Date
1 500 1 2015-11-17
2 1000 1 2015-11-15
3 300 1 2015-12-1
4 200 2 2015-11-2
I want to get results from mysql order by month. In my php page, I have a table structure for displaying data like shown below
State December November September
xx 300 1500 0
yy 0 200 0
Along with these months, I have a sorting link for sorting the amounts based on month. So when I click the sorting image corresponding to the month November, it should list the table data according to the order of amount in that column. If I clicked for ascending sorting it should list like,
State December November September
yy 0 200 0
xx 300 1500 0
I tried with following query :
SELECT ST.ST_Name,SUM(AT.AT_Amt)
FROM `Table2` AS AT
LEFT JOIN Table1 AS ST ON AT.ST_Id = ST.ST_Id
WHERE AT.Date BETWEEN '2015-04-01' AND '2015-12-31' GROUP BY MONTH( AT.Date) ORDER BY IF(MONTH(AT.Date) = 11 , SUM(AT.AT_Amt) , MONTH( AT.Date)) ASC
This query is returning data like shown below.
ST_Name SUM(AT.AT_Amt)
xx 300
xx 1700
But the expected result is :
ST_Name SUM(AT.AT_Amt)
yy 200
xx 1500
Can anyone please help me fix this? Thanks in advance.

Answer 1

You can do something like this:
SELECT
st_name,
SUM(CASE WHEN MONTH(dt) = 12 THEN at_amt ELSE 0 END) AS December,
SUM(CASE WHEN MONTH(dt) = 11 THEN at_amt ELSE 0 END) AS November,
SUM(CASE WHEN MONTH(dt) = 10 THEN at_amt ELSE 0 END) AS September
FROM table2
INNER JOIN table1 ON table1.st_id = table2.st_id
GROUP BY st_name;
Once you get data into PHP, you could just use JavaScript to do client-side sorting using TableSorter or similar library. That way sorting doesn't incur the expense of re-querying the database.
Result of your data will be:
+---------+----------+----------+-----------+
| st_name | December | November | September |
+---------+----------+----------+-----------+
| xx | 300 | 1500 | 0 |
| yy | 0 | 200 | 0 |
+---------+----------+----------+-----------+
Click the link below for a running demo:
SQLFiddle
EDIT:
Based on your comment, is this something you need?
SELECT
ST.ST_Name,
SUM(AT.AT_Amt) as Amount
FROM `Table2` AS AT
LEFT JOIN Table1 AS ST ON AT.ST_Id = ST.ST_Id
WHERE AT.dt BETWEEN '2015-04-01' AND '2015-12-31'
AND MONTH(AT.dt) = 11
GROUP BY ST.ST_Name
ORDER BY Amount
Example: http://sqlfiddle.com/#!9/51c7c/7 for demo
Result:
| st_name | Amount |
|---------|--------|
| yy | 200 |
| xx | 1500 |