Join results of 3 queries - sql

Question

i have 3 worked queries, but i don't know how to combin them in one query.
TABLES :
------------------ -------------------------- -----------------
PIECE MCARTEFIDENT MCARTEFIDLIG
------------------ -------------------------- -----------------
ET_LIBELLE : Store MFC_ETABLISSEMENT : STORE MFL_ETABLISSEMENT
GP_NUMERO : TICKET MFC_VALDISPOTHEO MFL_NBPASSAGEAPRES
------------------- --------------------------
--QUERY 1
select [et_libelle] AS [STORE NAME],COUNT([GP_NUMERO])
FROM PIECE
LEFT OUTER JOIN ETABLISS ET1 ON gp_etablissement=ET1.ET_ETABLISSEMENT
GROUP BY et_libelle
--QUERY 2
SELECT MFC_ETABLISSEMENT as [STORE NAME], COUNT (MFC_VALDISPOTHEO)
FROM MCARTEFIDENT
LEFT OUTER JOIN ETABLISS ET2 ON MFC_ETABLISSEMENT=ET2.ET_ETABLISSEMENT
GROUP BY MFC_ETABLISSEMENT
--QUERY 3
SELECT MFL_ETABLISSEMENT AS [STORE NAME], MFL_NBPASSAGEAPRES
FROM MCARTEFIDLIG
LEFT OUTER JOIN ETABLISS ET3 ON MFL_ETABLISSEMENT=ET3.ET_ETABLISSEMENT
GROUP BY MFL_ETABLISSEMENT
columns should be the result after combine :
[et_libelle] (Query 1),
COUNT([GP_NUMERO]) (Query 1),
COUNT([GP_NUMERO]) (Query 2),
MFL_NBPASSAGEAPRES (Query 3)

Answer 1

you could use your 3 queries as subqiery and join
select a.[STORE NAME], a.count_gp_numero, b.count_mfc_valdispotheo, c.MFL_NBPASSAGEAPRES
from (
select [et_libelle] AS [STORE NAME], COUNT([GP_NUMERO]) count_gp_numero
FROM PIECE
LEFT OUTER JOIN ETABLISS ET1 ON gp_etablissement=ET1.ET_ETABLISSEMENT
GROUP BY et_libelle
) a
left join (
SELECT MFC_ETABLISSEMENT as [STORE NAME], COUNT(MFC_VALDISPOTHEO) b.count_mfc_valdispotheo
FROM MCARTEFIDENT
LEFT OUTER JOIN ETABLISS ET2 ON MFC_ETABLISSEMENT=ET2.ET_ETABLISSEMENT
GROUP BY MFC_ETABLISSEMENT
) b on a.[STORE NAME] = b.[STORE NAME]
left join (
SELECT MFL_ETABLISSEMENT AS [STORE NAME], MFL_NBPASSAGEAPRES
FROM MCARTEFIDLIG
LEFT OUTER JOIN ETABLISS ET3 ON MFL_ETABLISSEMENT=ET3.ET_ETABLISSEMENT
GROUP BY MFL_ETABLISSEMENT
) c on a.[STORE NAME] = c.[STORE NAME]

Answer 2

If I had to speculate, my guess would be that you want:
select e.*,
(select count(*)
from piece p
where p.gp_etablissement = e.et_etablissement
),
(select count(*)
from MCARTEFIDENT mfc
where mfc.MFC_ETABLISSEMENT = e.et_etablissement
),
(select MFL_NBPASSAGEAPRES -- perhaps a `sum()` here???
from MCARTEFIDENT mfl
where mfl.MFL_ETABLISSEMENT = e.et_etablissement
)
from etabliss e;