Question

I’ve three tables in this mode:

Time1 with column “Data” in format gg/mm/aaaa

Manual with columns “valMan” and “dataora” same format.

Automatic with columns “valAuto” and “dataora” same format.

I must find values “valAuto” from table Automatic where Data.Time1 is = dataora.Automatic and if the value is null I take this value from valMan.Manual in the same Data.Time1 = dataora.Manual

In access sql or vb for access.

Is very important for me… Thank you a lot!!!

Answer 1

For MS Access you can try Iif and IsNull

SELECT  Time1.Data, 
        IIf(IsNull([valAuto]),[valMan],[valAuto]) AS Expr1
FROM    (Time1 LEFT JOIN Automatic ON Time1.Data = Automatic.dataora) LEFT JOIN 
        Manual ON Time1.Data = Manual.dataora;

or

Nz

SELECT  Time1.Data, 
        Nz([valAuto],[valMan]) AS Expr1
FROM    (Time1 LEFT JOIN Automatic ON Time1.Data = Automatic.dataora) LEFT JOIN 
        Manual ON Time1.Data = Manual.dataora;