>SELECT Client.Numero > FROM Client > LEFT JOIN Invoice ON Invoice.Numero=Client.NoInvoice AND Invoice.SecondCondition=True > LEFT JOIN Inventory ON Inventory.Numero=Client.NoInventory AND Inventory.SecondCondition=True > WHERE (EXISTS (SELECT Invoice.Numero FROM Invoice WHERE Invoice.Numero=Client.NoInvoice AND Invoice.SecondCondition=True) OR > EXISTS (SELECT Inventory.Numero FROM Inventory WHERE Inventory.Numero=Client.NoInventory AND Inventory.SecondCondition=True)) >Try this ?
select Client.Numero from Client join Invoice ON Invoice.Numero=Client.NoInvoice AND Invoice.SecondCondition=True union select Client.Numero from Client join Inventory ON Inventory.Numero=Client.NoInventory AND Inventory.SecondCondition=True