MYSQL Abfrage

SELECT
datum,
sum(netto) as tagessumme
FROM posten
WHERE YEAR(datum) = '2016'  
GROUP BY datum
ORDER BY tagessumme DESC
LIMIT 0,1

SELECT 
datum, 
sum(netto) - sum(kosten) as tagesergebnis 
FROM posten 
GROUP BY datum 
ORDER BY tagesergebnis DESC 
LIMIT 0,1

SELECT datum, 
(sum(kosten) / sum(netto)) as tagesrendite 
FROM posten 
GROUP BY datum 
ORDER BY tagesrendite DESC 
LIMIT 0,1

SELECT
(SELECT .. Abfrage für Januar)
(SELECT ...Abfrage für Februar)
usw.

SELECT kunden_id,MONTH(p.datum) AS Monat, SUM(p.netto) AS Umsatz FROM posten p WHERE YEAR(p.datum) = '2016' GROUP BY kunden_id,Monat ORDER BY Monat,Umsatz DESC LIMIT 0,15;  

+-----------+-------+--------+
| kunden_id | Monat | Umsatz |
+-----------+-------+--------+
|         1 |     4 |   1579 |
|         2 |     4 |   1518 |
|         1 |     5 |    130 |
|         2 |     5 |     90 |
+-----------+-------+--------+

SELECT alles.* from (

SELECT Month(datumsfeld) as Monat, Kunde,  sum(feld2) as SummeX, Avg( feld3) as Durchschnitt  ...
FROM posten WHERE year(datumsfeld) = 2016 and month(datumsfeld)  = 1 
GROUP BY Month(datumsfeld), Kunde
ORDER BY 3 desc
Limit 15

UNION ALL

SELECT Month(datumsfeld) as Monat, Kunde,  sum(feld2) as SummeX, Avg( feld3) as Durchschnitt  ...
FROM posten WHERE year(datumsfeld) = 2016 and month(datumsfeld) = 2
GROUP BY Month(datumsfeld), Kunde
ORDER BY 3 desc
Limit 15

UNION ALL
....

UNION ALL
SELECT Month(datumsfeld) as Monat, Kunde,  sum(feld2) as SummeX, Avg( feld3) as Durchschnitt  ...
FROM posten WHERE year(datumsfeld) = 2016 and month(datumsfeld) = 12
GROUP BY Month(datumsfeld), Kunde
ORDER BY 3 desc
Limit 15

 ) alles

SELECT Alles.Monat, Kunden.Kundenname, Alles.SummeX, Alles.Durchschnitt ...
FROM (

<siehe oben>
) Alles
join Kunden on Alles.kunde = Kunden.kundennummer

SELECT Alles.Monat, Kunden.Kundenname, Alles.Umsatz FROM (

( SELECT 'Jan'  as Monat, Kunden_id,  sum(netto) as Umsatz  
FROM posten WHERE year(datum) = 2016 and month(datum)  = 1 
GROUP BY Kunden_id
ORDER BY 3 desc
Limit 15
)
UNION ALL
(
SELECT 'Feb'  as Monat, Kunden_id,  sum(netto) as Umsatz  
FROM posten WHERE year(datum) = 2016 and month(datum) = 2
GROUP BY Kunden_id
ORDER BY 3 desc
Limit 15
) 

UNION ALL 
( SELECT ...März nach Schema F)
...
UNION ALL 
( SELECT ...Dezember nach Schema F )

) Alles
join Kunden on Alles.kunden_id = Kunden.kunden_id