FoxPro form not updating tables - database

Question

I've created a very simple form with two textboxes and an 'update locations' button, the inputted values of which should be updating to two linked tables in a database. I'm eventually trying to put this in a standalone application but for now I just want the form itself to work. I'm very new to FoxPro so I don't know if it's possible for just a form to update my tables, or if there's some other issue at work.
Here's the code for my 'update locations' button (OldLoc is the first textbox and NewLoc the second):
SET DATABASE TO LOCATIONS
CLOSE ALL DATABASES
OPEN DATABASE locations\locations EXCLUSIVE
IF this.parent.OldLoc.Value == "" then
MESSAGEBOX('Please fill in the old location.', 48, 'Missing Location Information')
this.parent.OldLoc.SetFocus
ELSE
INDEX ON table1.loc TAG loc
SET ORDER TO loc
SEEK this.parent.OldLoc.Value IN table1
IF FOUND()
IF this.parent.NewLoc.Value == "" then
MESSAGEBOX('Please fill in the new location.', 48,
'Missing Location Information') this.parent.NewLoc.SetFocus
UPDATE table1 SET loc = this.parent.NewLoc.Value ;
WHERE loc = this.parent.OldLoc.value
UPDATE table2 SET loc = this.parent.NewLoc.Value ;
WHERE loc = this.parent.OldLoc.value
ENDIF
ENDIF
ENDIF
Any input you have is appreciated!

Answer 1

you are doing redundant work in your click event... Closing the database, then re-opening, then opening exclusive. The tables you are trying to update, should already have an index on the key columns you ever plan to join or search based on. Once that is done, you don't need to explicitly create the index tag over and over... Once an index "TAG" is created, you don't need to do again..
So, that being said...
Open the form, and open the "INIT" event. In there, that is where you can explicitly open the tables for use while the form is in use...
IF NOT DBUSED( "Locations" )
*/ You only need exclusive if you will be modifying the database.
*/ The indexes should already exist before the form ever starts
Open Database Locations\Locations SHARED
ENDIF
Now, the "CLICK" event of your update button... Pre-validate that there are values, don't worry about trying to seek or update unless BOTH are filled in...
IF ALLTRIM( This.Parent.OldLoc.Value ) == "";
OR ALLTRIM( This.Parent.NewLoc.Value ) == ""
*/ Simple one message about BOTH being required
messagebox( "Please fill in both Old and New Locations.", 48, ;
"Missing Location Information" )
ENDIF
*/ Then, update... if no entries match, no records will be updated.
*/ VFP sometimes chokes with multiple "." values such as form values
*/ as SQL commands are expecting "alias.field" format...
lcOldValue = This.Parent.OldLoc.Value
lcNewValue = This.Parent.NewLoc.Value
Update Locations!Table1;
set Loc = lcNewLoc;
where Loc = lcOldLoc
*/ Were there any updates?
llAnyUpdates = _Tally > 0
*/ Now, the OTHER table too...
Update Locations!Table1;
set Loc = lcNewLoc;
where Loc = lcOldLoc
*/ Were there any updates on THIS cycle...
llAnyUpdates = llAnyUpdates OR _Tally > 0
if llAnyUpdates
messagebox( "Locations have been updated.", 0, "Update complete" )
else
messagebox( "No such location found to be updated.", 0, "No Records Updated" )
endif

Answer 2

You might also want to take a look at the data environment of the form.
You can select which tables the form is to open when the form loads, this saves explicitly opening them either in the forms load event or in the forms init event
My humble offering for the Click Event of the 'Update Locations' button is :-
LOCAL lcOldLoc,lcNewLoc
WITH THISFORM
lcOldLoc=.oldloc.VALUE
lcNewLoc=newloc.VALUE
DO CASE
CASE EMPTY(lcOldLoc)
MESSAGEBOX("PLEASE ENTER OLD LOCATION",16,"ERROR")
CASE EMPTY(lcNewLoc)
MESSAGEBOX("NEW LOCATION CAN'T BE EMPTY",16,"ERROR")
OTHERWISE
UPDATE table1 SET loc=lcNewLoc WHERE loc=lcOldLoc
DO CASE
CASE _TALLY=0
MESSAGEBOX("OLD LOCATION NOT FOUND",16,"ERROR")
OTHERWISE
UPDATE tabel2 SET loc=lcNewLoc WHERE loc=lcOldLoc
ENDCASE
ENDCASE
ENDWITH
This should be the only code required. Clearly there are many improvements that can be made to the above , but in essence that will do the job.
If you would like to see the above form built from scratch, pop an email to support#foxsoft.co.uk and I will give you a live demonstration.