Android Question SQLite don't keep changes

[Ruben García]

Hello,

I have a problem in SQLite.

First open database :

If File.Exists(File.DirDefaultExternal , DBName) = False Then
If FirstTime Then
File.Copy(File.DirAssets, DBName, File.DirDefaultExternal, DBName)
sql1.Initialize(File.DirDefaultExternal , DBName, True)
End If
Else
If FirstTime Then
sql1.Initialize(File.DirDefaultExternal , DBName, True)
End If
End If

Then I update a table, close activity, open activity and changes are OK.

But when I close application and open again I have lost the changes.

¿can anybody help me?

Thank you

 

[Mahares]

You code should be like this:

If FirstTime Then

    if File.Exists(File.DirDefaultExternal , DBName) = False Then
      File.Copy(File.DirAssets,DBName, File.DirDefaultExternal,DBName)
    end if
    sql1.Initialize(File.DirDefaultExternal ,DBName, True)
end if

 

[eps]

Whilst the code Mahares has posted is a lot neater and easier to read it should produce the same result.

Are you sure the DirDefaultExternal is a useable and maintainable filespace? What device have you got?

I usually use DirInternal instead as it's a more useable filespace in most devices.

ETA: I would also confirm, whilst you're in your App that the Update has worked.

i.e.

Open App

Update / Add record

Check record has been updated

Close App

Reopen and View.

If you step through the processing in your App I'm sure the issue will become apparent. The Android App lifecycle can be a little misleading sometimes and it causes you to make assumptions about what code is being executed. Sometimes it can surprise you (I've been surprised more than once by B4A code!!)

 

[eps]

What Android Version are you testing with?

 

[Erel]

Note that there is a method in DBUtils named CopyDBFromAssets. It is similar to the code posted by @Mahares however it also checks that the external storage is writable. If not it copies it to an internal folder (and returns the actual folder).

 

[Ruben García]

Thanks for the replies.

The problem persists. I step through the processing , and check record has been updated. The problem is when I close the application and reopen, the changes are lost, as if I had not recorded.

The android version is 4.2.2.

I have seen the sql file does not change the modification date. But there is another file in the same directory (bd.sqlite-journal) that changed the modification date.

any idea to investigate?

 

[klaus]

Are you sure you don't have
File.Delete(File.DirDefaultExternal, DBName)
somewhere before the code you posted ?

 

[Ruben García]

I'm sure Klaus. Also I check the program jump this conditional instruction.

If File.Exists(TargetDir, FileName) = False Then
File.Copy(File.DirAssets, FileName, TargetDir, FileName)
End If

 

[klaus]

Can you post your project as a zip file.

 

[Ruben García]

Resolved!!!!

I began a SQL transaction that never completed. I have completed the transaction and works fine.

Thank you all for your help.