iOS Question Inconsistent SQLite behavior on iOS

Alessandro71

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Longtime User
I know this is not a proper bug report, but actually I have no clues and isolating the code in a sample project is a lot of work, so I might just ask if someone had similar issues and might have a clue on what's going on.

The same code works fine on B4A and B4J
On B4i, the same query, repeated with no other code in between, gives different results

Here is the resumable sub that reads a table from DB, and fills a list with the results
B4X: 
Public Sub Read(day As Long, location As String) As ResumableSub
    Dim entries As List
    entries.Initialize

    Try
        Dim SenderFilter As Object = DB.ExecQueryAsync("SQL", "SELECT timestamp,provider,forecast,mint,maxt FROM meteo WHERE day=? AND location=?", Array As String(day, location))
        Wait For (SenderFilter) SQL_QueryComplete (Success As Boolean, rs As ResultSet)
        If Success Then
            Do While rs.NextRow
                Dim m As MeteoEntry = Meteo.CreateMeteoEntry( _
                    rs.GetLong("timestamp"), _
                    rs.GetString("provider"), _
                    day, _
                    rs.GetString("forecast"), _
                    rs.GetInt("mint"), _
                    rs.GetInt("maxt") _
                )
                entries.Add(m)
            Loop
            rs.Close
        Else
            WriteLog("error reading")
        End If
    Catch
        ExceptionHandler.Manage("MeteoDB.Read", ExceptionHandler.EXCEPTION_CRITICAL)
    End Try
    
    Return entries
End Sub

Now the code that calls the above sub

B4X: 
        Wait For (Globals.database.Read(forecastday, location)) Complete (entries As List)
        WriteLog($"entries ${entries.Size}"$)
        
        Wait For (Globals.database.Read(forecastday, location)) Complete (entries1 As List)
        WriteLog($"entries ${entries1.Size}"$)

        Wait For (Globals.database.Read(forecastday, location)) Complete (entries2 As List)
        WriteLog($"entries ${entries2.Size}"$)

In the log I find:
entries 3
entries 76
entries 3

usually I find one of those cases:
1) all 3 entries numbers are the same (that is what is expected)
2) 1 or 2 numbers are different and the order of the "wrong ones" may differ at each run
 
Solution
Alessandro71 said:
Dim SenderFilter As Object = DB.ExecQueryAsync("SQL", "SELECT timestamp,provider,forecast,mint,maxt FROM meteo WHERE day=? AND location=?", Array As String(day, location))
Click to expand...
try this:
B4X: 
 Dim SenderFilter As Object = DB.ExecQueryAsync("SQL", "SELECT timestamp,provider,forecast,mint,maxt FROM meteo WHERE day=? AND location=?", Array As Object(day, location))
i changed the Array As String to Array As Object
In the past had problems with the Array As String in SQL. Maybe it helps.
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Alexander Stolte

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Longtime User
Alessandro71 said:
Dim SenderFilter As Object = DB.ExecQueryAsync("SQL", "SELECT timestamp,provider,forecast,mint,maxt FROM meteo WHERE day=? AND location=?", Array As String(day, location))
Click to expand...
try this:
B4X: 
 Dim SenderFilter As Object = DB.ExecQueryAsync("SQL", "SELECT timestamp,provider,forecast,mint,maxt FROM meteo WHERE day=? AND location=?", Array As Object(day, location))
i changed the Array As String to Array As Object
In the past had problems with the Array As String in SQL. Maybe it helps.
 
Upvote 0
Solution

Alessandro71

Well-Known Member
Licensed User
Longtime User
looks like you nailed it: now all calls returns the same number of entries.
thank you
@Erel this looks to be a candidate for the "code smell" thread
 
Upvote 0
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