SQL close

[timo]

I'm a little old fashionned, but it souds me strange not to close a database. You close cursors and transactions but not a db. DB stay most of the time open resident with the app when the app is "closed". Is there any problem in closing a db on going out and then evaluate it's state by 'db.IsInitialised' on resume?. Which is the best way to follow with android? (I mean with SQLite)
Thanks

 

[Smee]

Hi Timo,

I always close my db upon exit. I have exited the program and gone straight back in without testing the status of the database. It sems to work ok for me

Joe

 

[timo]

but if you reopen your app while resident, without testing it in Resume (and opened in cerate (firstTime) you will have a java exception (DB not open).

Another question: what are db-wal and db-shm autocreated?

 

[Smee]

Hi Timo,

I always close my db upon exit. I have exited the program and gone straight back in without testing the status of the database. It sems to work ok for me

Joe

As i said above. I do not get an error. the db is always opened ok

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime=True Then
      SQL.Initialize(File.DirInternal, "WDOrders.db", True)

....
...
...
end sub

Sub Activity_Keypress (KeyCode As Int) As Boolean
Dim Answ As Int
Dim Txt As String
Log(KeyCode)

If KeyCode=KeyCodes.KEYCODE_BACK Then
   Txt = "Do you really want to Quit the Program ?"
   Answ=Msgbox2(Txt,"ATTENTION","Yes","","No",LoadBitmap(File.DirAssets,"quit.gif"))
   If Answ=DialogResponse.POSITIVE Then
      SQL.Close
           end if
end if

 

[timo]

sorry, but this way on 'second time' it remains closed. It happens when Android let your app resident in backgroud. If you never get the error, i think you're lucky

Try exit yor app and immediately reopen it. Do it four o five times.

 

[Erel]

Is there any problem in closing a db on going out and then evaluate it's state by 'db.IsInitialised' on resume?

There is no problem. I recommend you to close it only when UserClosed is True. Otherwise the database will be closed and reopened when the orientation changes.

 

[Mahares]

I recommend you to close it only when UserClosed is True

Do I need to close the SQL object before I exit an app when I am immediately starting another application that opens the same database as the app I am exiting? If so, what do I need besides closing the cursor and: SQL1.Close

 

[Erel]

SQLite can handle concurrent access from several processes. You should make sure that all transactions and cursors are closed when they are on longer required.

It is a good practice to close SQL when it is no longer used. Especially if you access it from different applications.