Error GROUP BY Dates MysQL - mysql

Question

I am trying to group by dates 2 different tables. However, something is going wrong as I am not able to group by dates.
I have 2 tables First "Budget" and Second "Sales Performance By Region"
The Idea is to show the Budget for all the months (12 months)
and each month we have data we will see the Sales for each specific month.
SELECT
BB.RG,
BB.YEAR,
DATE_FORMAT( BB.MONTH, '%M' ) AS `MONTH`,
SPR.Bookings,
SPR.`Bookings PY`,
SPR.Billing,
SPR.`Billing PY`,
SPR.`GP Amt`,
SPR.`GP Amt PY`,
SUM( BB.BUDGET ) AS BUDGET
FROM
BRANCH_BUDGET BB
LEFT JOIN Sales_Performance_Region SPR
ON BB.MONTH = SPR.MONTH
WHERE
BB.RG = 'FE'
AND SPR.RG = 'FE'
AND BB.YEAR = '2018'
GROUP BY
BB.MONTH
Above you can see the code. Instead of showing the 12 Months due to I only have data for 2 Months is showing January and February.
I hope the question makes sense. Can you guide me?

Answer 1

Whenever you invoke a GROUP BY after a WHERE statement or any other aggregate function inside a SELECT statement you will need to treat everything inside the select statement as an aggregate, otherwise you will face problems:
In your code:
SELECT `BRANCH_BUDGET`.`RG` ,
`BRANCH_BUDGET`.`YEAR` AS `YEAR` ,
`DATE_FORMAT( `BRANCH_BUDGET`.`MONTH` , '%M' ) AS `MONTH` ,
`Sales_Performance_Region`.`Bookings` ,
`Sales_Performance_Region`.`Bookings PY` ,
`Sales_Performance_Region`.`Billing` ,
`Sales_Performance_Region`.`Billing PY` ,
`Sales_Performance_Region`.`GP Amt` ,
`Sales_Performance_Region`.`GP Amt PY` ,
SUM( `BRANCH_BUDGET`.`BUDGET` ) AS `BUDGET`
FROM (
`BRANCH_BUDGET`
LEFT JOIN `Sales_Performance_Region` ON ( `BRANCH_BUDGET`.`MONTH` =
`Sales_Performance_Region`.`MONTH` )
)
WHERE `BRANCH_BUDGET`.`RG` = 'FE'
AND `Sales_Performance_Region`.`RG` = 'FE'
AND `BRANCH_BUDGET`.`YEAR` = '2018'
GROUP BY `BRANCH_BUDGET`.`MONTH`
You only group by BRANCH_BUDGET.MONTH, but do not group by any other column or perform an aggregate function on any other column (save BRANCH_BUDGET.BUDGET). Thus your output is faulty in that it only returns two months.

Answer 2

First thanks for the comments I want to post the result in case someone is interested.
The issue was: I didn't join the Region (RG) from both tables. So the result should look like the code below:
SELECT `BRANCH_BUDGET`.`RG` ,
`BRANCH_BUDGET`.`YEAR` AS `YEAR` ,
DATE_FORMAT( `BRANCH_BUDGET`.`MONTH` , '%M' ) AS `MONTH` ,
`Sales_Performance_Region`.`Bookings` ,
`Sales_Performance_Region`.`Bookings PY` ,
`Sales_Performance_Region`.`Billing` ,
`Sales_Performance_Region`.`Billing PY` ,
`Sales_Performance_Region`.`GP Amt` ,
`Sales_Performance_Region`.`GP Amt PY` ,
SUM( `BRANCH_BUDGET`.`BUDGET` ) AS `BUDGET`
FROM (
`BRANCH_BUDGET`
LEFT JOIN `Sales_Performance_Region`
ON ( `Sales_Performance_Region`.`MONTH` = `BRANCH_BUDGET`.`MONTH` )
AND ( `Sales_Performance_Region`.`RG` = `BRANCH_BUDGET`.`RG` )
)
WHERE `BRANCH_BUDGET`.`RG` = 'FE'
AND `BRANCH_BUDGET`.`YEAR` = '2018'
GROUP BY `BRANCH_BUDGET`.`MONTH`