dblookupcombobox in dbgrid

[Pier]

I am sure it must be trivial, and I am aware of the demo () in which KeyField=country and ListField=country, however I do not seem to able to achieve what I want.

Let me try to explain

Table1: InvoiceNo:INTEGER(11), CustID:INTEGER(11) - Data (111,1) (222,2) (333,3) (444,1)

Table2: ID:INTEGER(11), Customer:CHARACTER(4) - Data (1,'John') (2,'Bill') (3,'Jane') (4,'Mary')

The grid should show

111   John

222   Bill

333   Jane

444    John

When we click on 'Bill' we should get a combo listing John/Bill/Jane/Mary. If we select Mary the second row in Table1 should become (222,4).

How is this achieved? How specifically should the TVCLDBColumn in the TUniDBGrid and the hidden TUniDBLookupComboBox be set?

Your help would be greatly appreciated.

[Pier]

Nobody has a clue? Even a "NO, it's impossible" would help. This is a real show-stopper for the application I want to develop because essentially al the database structure is built with ids pointing to records in other tables.

[alfr]

You need to specify also the datasource and datafield in the uniDbLookupcombo. They would normally be set to the same datasource as the unidbgrid. So in your case datasource should point to table1 and the datafield should be the CustID. 

(and the listsource should be set to the customer datasource. Keyfield = ID and ListField = Customer)

[Pier]

Thanks alfr. This is what I tried. What I see in the table, though, is

111   1

222   2

333   3

444    1

(the dropdown is ok). Can you confirm that it should definitely work inside a dbgrid? I have been fighting with this for days... do you know of a microdemo that shows such a case working?

 

 

 

[alfr]

ok, what is missing is that you also need to add a lookup field in your table1 query. This is the field that you should show in the Unidbgrid. (The CustID can be hidden)

Something like the below. So in the fields editor select "New Field". 

[Pier]

THANKS! I owe you a big one! Thanks again!

(I come from devexpress VCL components where things are a bit more straightforward, but I know this is quite a different game)

 

[Freeman35]

@alfr if I were you, I'm  not use TFields's lookup field. 'cos so much lost performans it. write join in SQL text its öuch better it. or maybe need case statement, I perfer write this in sql too. or write stored procedure in db (if saported)

[alfr]

@Freeman35 yes, I agree that in most cases this would be preferred. However in the example he was looking at and didn't understand they were using the lookup field. 

[Pier]

Thanks for the suggestion of using JOINs instead of TFields's lookup.