I'm trying to get in the same result the last 12 months and their values vs same months from the last year and the percentage difference.
ThisYearMonth | ThisYearValue | LastYearMonth | LastYearDifAsPercent
--------------|---------------|---------------|---------------------
Dec 2015 -----|800 -----------|Dec 2014 ------|50 ------------------
Nov 2015 -----|350 -----------|Nov 2014 ------|-23 -----------------
Each select works OK, but when combined, i get
[Err] 1242 - Subquery returns more than 1 row
SELECT
DATE_FORMAT(`month`, '%b %Y') AS ThisYearMonth,
no_customer_growth as ThisYearCustGrowth,
DATE_FORMAT(DATE_SUB(`month`, INTERVAL 1 YEAR),'%b %Y') AS `LastYearMonth`,
(
SELECT
ROUND((t1.no_customer_growth - t2.no_customer_growth) / t2.no_customer_growth * 100, 2)
FROM cust_evolution AS t1
INNER JOIN cust_evolution AS t2
ON DATE_FORMAT(t1.`month`,'%b') = DATE_FORMAT(t2.`month`,'%b')
AND DATE_FORMAT(t1.`month`,'%Y') = DATE_FORMAT(t2.`month`,'%Y') - 1
) AS `MoM % growth`
FROM cust_evolution
Thanks for your time and support!