[Gambas-user] Looking up data from a second table

[T Lee Davidson]

On 02/19/2018 07:47 PM, Christof Thalhofer wrote:
> Am 20.02.2018 um 00:03 schrieb T Lee Davidson:
> 
>> I think the DataSource should be set programatically.
> 
> For sure. This can be done easily in a module:
> 
> --8<-------------------------------------------------------------------
> 
> Property Read MyDB as Connection
> Private $MyDB as Connection
> 
> Private Function MyDB_Read() As Connection
> 
>     If Not $MyDB.Opened Then
>     	With $MyDB
>         	.Type = "postgresql" ' sqlite3, mysql
>         	.Host = "hostname"
>         	.Name = "dbname"
>         	.Login = "username"
>         	.Password = "password123456"
>         End With
>         Open($MyDB)
>     Endif
> 
>     Return $MyDB
> Catch
>     Error.Propagate
> 
> End
> 
> --8<-------------------------------------------------------------------
> 
> If you save this module with the name "DBs.module" then one can use the
> connection anywhere in the program like so:
> 
> --8<-------------------------------------------------------------------
> 
> Dim Qry as String
> Dim Res as Result
> 
> Qry = "select str from anything;"
> Res = DBs.MyDB.Exec(Qry)
> 
> --8<-------------------------------------------------------------------
> 
> Or for a DataSource:
> 
> --8<-------------------------------------------------------------------
> 
> 	DataSource1.Connection = DBs.MyDB
> 	DataSource1.Table = "select this from that;"
> 
> --8<-------------------------------------------------------------------

Nice.

And if one does not need to easily use the connection from multiple forms, the connection can simply be defined and opened in
the main form's Open event:

Public Sub Form_Open()

  Dim hConn As Connection
  hConn = New Connection("sqlite3://" & User.Home &/ "db.sqlite")
  Try hConn.Open()
  If Error Then
    Debug "Cannot open database."
    Return
  Endif

  DataSource1.Connection = hConn
  DataSource1.Table = "select this from that;"

End


> For the problem of the OP: I was not able to display the data in a
> DataView. I do not understand how the DataView corresponds with the
> DataSource, beecause I do not work with gb.db.form.

The DataView should be a child of DataSource so that it 'inherits' the connection.


-- 
Lee