SELECT c.denomination AS cooperative, AVG(te.surface) AS moyenne, AVG(te.nombre_parcelles) AS moy_nombre_parcelles, SUM(te.surface) AS total, COUNT(te.id) AS nombre_exploitations FROM tbl_organisations c LEFT JOIN tbl_organisations g ON c.id = g.parent_id LEFT JOIN pivot_exploitation_organisations p ON g.id = p.organisation_id LEFT JOIN tbl_organisation_level tol ON c.level_id=tol.id LEFT JOIN ( SELECT SUM(par.surface) as surface, COUNT(par.id) AS nombre_parcelles, e.id FROM exploitations e, parcelles par WHERE par.exploitation_id=e.id GROUP BY e.id) te ON te.id=p.exploitation_id WHERE tol.level=1 GROUP BY c.id