Android Question Read/write problems to storage

File.Copy(File.DirAssets,db,File.DirDefaultExternal,db)
SQL.Initialize(File.DirDefaultExternal,db,False)

Private Db As String = "mystuff.db3"
Private DbPath As String = File.DirDefaultExternal
File.Copy(File.DirAssets,Db,DbPath,Db)

'DBUtils
' Version 1.20
Sub Process_Globals
    Public DB_REAL, DB_INTEGER, DB_BLOB, DB_TEXT As String
    DB_REAL = "REAL"
    DB_INTEGER = "INTEGER"
    DB_BLOB = "BLOB"
    DB_TEXT = "TEXT"
    Dim HtmlCSS As String
    HtmlCSS = $"
        table {width: 100%;border: 1px solid #cef;text-align: left; }
        th { font-weight: bold;    background-color: #acf;    border-bottom: 1px solid #cef; }
        td,th {    padding: 4px 5px; }
        .odd {background-color: #def; }
        .odd td {border-bottom: 1px solid #cef; }
        a { text-decoration:none; color: #000;}"$
End Sub

'Returns the path to a folder where you can create a database, preferably on the secondary storage.
Public Sub GetDBFolder As String
    Dim rp As RuntimePermissions
    If File.ExternalWritable Then Return rp.GetSafeDirDefaultExternal("") Else Return File.DirInternal
End Sub

'Copies a database file that was added in the Files tab. The database must be copied to a writable location.
'This method copies the database to the storage card. If the storage card is not available the file is copied to the internal folder.
'The target folder is returned.
'If the database file already exists then no copying is done.
Public Sub CopyDBFromAssets (FileName As String) As String
    Dim TargetDir As String = GetDBFolder
   
    If File.Exists(TargetDir, FileName) = False Then
        File.Copy(File.DirAssets, FileName, TargetDir, FileName)
    End If
    Return TargetDir
End Sub

'Creates a new table with the given name.
'FieldsAndTypes - A map with the fields names as keys and the types as values.
'You can use the DB_... constants for the types.
'PrimaryKey - The column that will be the primary key. Pass empty string if not needed.
Public Sub CreateTable(SQL As SQL, TableName As String, FieldsAndTypes As Map, PrimaryKey As String)
    Dim sb As StringBuilder
    sb.Initialize
    sb.Append("(")
    For i = 0 To FieldsAndTypes.Size - 1
        Dim field, ftype As String
        field = FieldsAndTypes.GetKeyAt(i)
        ftype = FieldsAndTypes.GetValueAt(i)
        If i > 0 Then sb.Append(", ")
        sb.Append("[").Append(field).Append("] ").Append(ftype)
        If field = PrimaryKey Then sb.Append(" PRIMARY KEY")
    Next
    sb.Append(")")
    Dim query As String
    query = "CREATE TABLE IF NOT EXISTS [" & TableName & "] " & sb.ToString
    Log("CreateTable: " & query)
    SQL.ExecNonQuery(query)
End Sub

'Deletes the given table.
Public Sub DropTable(SQL As SQL, TableName As String)
    Dim query As String
    query = "DROP TABLE IF EXISTS [" & TableName & "]"
    Log("DropTable: " & query)
    SQL.ExecNonQuery(query)
End Sub

'Inserts the data to the table.
'ListOfMaps - A list with maps as items. Each map represents a record where the map keys are the columns names
'and the maps values are the values.
'Note that you should create a new map for each record (this can be done by calling Dim to redim the map).
Public Sub InsertMaps(SQL As SQL, TableName As String, ListOfMaps As List)
    Dim sb, columns, values As StringBuilder
    'Small check for a common error where the same map is used in a loop
    If ListOfMaps.Size > 1 And ListOfMaps.Get(0) = ListOfMaps.Get(1) Then
        Log("Same Map found twice in list. Each item in the list should include a different map object.")
        Return
    End If
    SQL.BeginTransaction
    Try
        For i1 = 0 To ListOfMaps.Size - 1
            sb.Initialize
            columns.Initialize
            values.Initialize
            Dim listOfValues As List
            listOfValues.Initialize
            sb.Append("INSERT INTO [" & TableName & "] (")
            Dim m As Map
            m = ListOfMaps.Get(i1)
            For i2 = 0 To m.Size - 1
                Dim col As String
                Dim value As Object  
                col = m.GetKeyAt(i2)
                value = m.GetValueAt(i2)
                If i2 > 0 Then
                    columns.Append(", ")
                    values.Append(", ")
                End If
                columns.Append("[").Append(col).Append("]")
                values.Append("?")
                listOfValues.Add(value)
            Next
            sb.Append(columns.ToString).Append(") VALUES (").Append(values.ToString).Append(")")
            If i1 = 0 Then Log("InsertMaps (first query out of " & ListOfMaps.Size & "): " & sb.ToString)
            SQL.ExecNonQuery2(sb.ToString, listOfValues)
        Next
        SQL.TransactionSuccessful
    Catch
        ToastMessageShow(LastException.Message, True)
        Log(LastException)
    End Try
    SQL.EndTransaction
End Sub

' updates a single field in a record
' Field is the column name
Public Sub UpdateRecord(SQL As SQL, TableName As String, Field As String, NewValue As Object, _
    WhereFieldEquals As Map)
    Dim sb As StringBuilder
    sb.Initialize
    sb.Append("UPDATE [").Append(TableName).Append("] SET [").Append(Field).Append("] = ? WHERE ")
    If WhereFieldEquals.Size = 0 Then
        Log("WhereFieldEquals map empty!")
        Return
    End If
    Dim args As List
    args.Initialize
    args.Add(NewValue)
    For i = 0 To WhereFieldEquals.Size - 1
        If i > 0 Then sb.Append(" AND ")
        sb.Append("[").Append(WhereFieldEquals.GetKeyAt(i)).Append("] = ?")
        args.Add(WhereFieldEquals.GetValueAt(i))
    Next
    Log("UpdateRecord: " & sb.ToString)
    SQL.ExecNonQuery2(sb.ToString, args)
End Sub

' updates multiple fields in a record
' in the Fields map the keys are the column names
Public Sub UpdateRecord2(SQL As SQL, TableName As String, Fields As Map, WhereFieldEquals As Map)
    If WhereFieldEquals.Size = 0 Then
        Log("WhereFieldEquals map empty!")
        Return
    End If
    If Fields.Size = 0 Then
        Log("Fields empty")
        Return
    End If
    Dim sb As StringBuilder
    sb.Initialize
    sb.Append("UPDATE [").Append(TableName).Append("] SET ")
    Dim args As List
    args.Initialize
    For i=0 To Fields.Size-1
        If i<>Fields.Size-1 Then
            sb.Append("[").Append(Fields.GetKeyAt(i)).Append("]=?,")
        Else
            sb.Append("[").Append(Fields.GetKeyAt(i)).Append("]=?")
        End If
        args.Add(Fields.GetValueAt(i))
    Next
   
    sb.Append(" WHERE ")
    For i = 0 To WhereFieldEquals.Size - 1
        If i > 0 Then
            sb.Append(" AND ")
        End If
        sb.Append("[").Append(WhereFieldEquals.GetKeyAt(i)).Append("] = ?")
        args.Add(WhereFieldEquals.GetValueAt(i))
    Next
    Log("UpdateRecord: " & sb.ToString)
    SQL.ExecNonQuery2(sb.ToString, args)
End Sub

'Executes the query and returns the result as a list of arrays.
'Each item in the list is a strings array.
'StringArgs - Values to replace question marks in the query. Pass Null if not needed.
'Limit - Limits the results. Pass 0 for all results.
Public Sub ExecuteMemoryTable(SQL As SQL, Query As String, StringArgs() As String, Limit As Int) As List
    Dim cur As Cursor
    If StringArgs <> Null Then
        cur = SQL.ExecQuery2(Query, StringArgs)
    Else
        cur = SQL.ExecQuery(Query)
    End If
    Log("ExecuteMemoryTable: " & Query)
    Dim table As List
    table.Initialize
    If Limit > 0 Then Limit = Min(Limit, cur.RowCount) Else Limit = cur.RowCount
    For row = 0 To Limit - 1
        cur.Position = row
        Dim values(cur.ColumnCount) As String
        For col = 0 To cur.ColumnCount - 1
            values(col) = cur.GetString2(col)
        Next
        table.Add(values)
    Next
    cur.Close
    Return table
End Sub

'Executes the query and returns a Map with the column names as the keys
'and the first record values As the entries values.
'The keys are lower cased.
'Returns Null if no results found.
Public Sub ExecuteMap(SQL As SQL, Query As String, StringArgs() As String) As Map
    Dim cur As Cursor
    If StringArgs <> Null Then
        cur = SQL.ExecQuery2(Query, StringArgs)
    Else
        cur = SQL.ExecQuery(Query)
    End If
    Log("ExecuteMap: " & Query)
    If cur.RowCount = 0 Then
        Log("No records found.")
        Return Null
    End If
    Dim res As Map
    res.Initialize
    cur.Position = 0
    For i = 0 To cur.ColumnCount - 1
        res.Put(cur.GetColumnName(i).ToLowerCase, cur.GetString2(i))
    Next
    cur.Close
    Return res
End Sub

'Executes the query and fills the Spinner with the values in the first column
Sub ExecuteSpinner(SQL As SQL, Query As String, StringArgs() As String, Limit As Int, Spinner1 As Spinner)
    Spinner1.Clear
    Dim Table As List
    Table = ExecuteMemoryTable(SQL, Query, StringArgs, Limit)
    Dim Cols() As String
    For i = 0 To Table.Size - 1
        Cols = Table.Get(i)
        Spinner1.Add(Cols(0))
    Next
End Sub

'Executes the query and fills the ListView with the value.
'If TwoLines is true then the first column is mapped to the first line and the second column is mapped
'to the second line.
'In both cases the value set to the row is the array with all the records values.
Public Sub ExecuteListView(SQL As SQL, Query As String, StringArgs() As String, Limit As Int, ListView1 As ListView, _
    TwoLines As Boolean)
    ListView1.Clear
    Dim Table As List
    Table = ExecuteMemoryTable(SQL, Query, StringArgs, Limit)
    Dim Cols() As String
    For i = 0 To Table.Size - 1
        Cols = Table.Get(i)
        If TwoLines Then
            ListView1.AddTwoLines2(Cols(0), Cols(1), Cols)
        Else
            ListView1.AddSingleLine2(Cols(0), Cols)
        End If
    Next
End Sub

'Executes the given query and creates a Map that you can pass to JSONGenerator and generate JSON text.
'DBTypes - Lists the type of each column in the result set.
'Usage example: (don't forget to add a reference to the JSON library)
'    Dim gen As JSONGenerator
'    gen.Initialize(DBUtils.ExecuteJSON(SQL, "SELECT Id, Birthday FROM Students", Null, _
'        0, Array As String(DBUtils.DB_TEXT, DBUtils.DB_INTEGER)))
'    Dim JSONString As String
'    JSONString = gen.ToPrettyString(4)
'    Msgbox(JSONString, "")
Public Sub ExecuteJSON (SQL As SQL, Query As String, StringArgs() As String, Limit As Int, DBTypes As List) As Map
    Dim table As List
    Dim cur As Cursor
    If StringArgs <> Null Then
        cur = SQL.ExecQuery2(Query, StringArgs)
    Else
        cur = SQL.ExecQuery(Query)
    End If
    Log("ExecuteJSON: " & Query)
    Dim table As List
    table.Initialize
    If Limit > 0 Then Limit = Min(Limit, cur.RowCount) Else Limit = cur.RowCount
    For row = 0 To Limit - 1
        cur.Position = row
        Dim m As Map
        m.Initialize
        For i = 0 To cur.ColumnCount - 1
            Select DBTypes.Get(i)
                Case DB_TEXT
                    m.Put(cur.GetColumnName(i), cur.GetString2(i))
                Case DB_INTEGER
                    m.Put(cur.GetColumnName(i), cur.GetLong2(i))
                Case DB_REAL
                    m.Put(cur.GetColumnName(i), cur.GetDouble2(i))
                Case Else
                    Log("Invalid type: " & DBTypes.Get(i))
            End Select
        Next
        table.Add(m)
    Next
    cur.Close
    Dim root As Map
    root.Initialize
    root.Put("root", table)
    Return root
End Sub

'Creates a html text that displays the data in a table.
'The style of the table can be changed by modifying HtmlCSS variable.
Public Sub ExecuteHtml(SQL As SQL, Query As String, StringArgs() As String, Limit As Int, Clickable As Boolean) As String
    Dim cur As Cursor
    If StringArgs <> Null Then
        cur = SQL.ExecQuery2(Query, StringArgs)
    Else
        cur = SQL.ExecQuery(Query)
    End If
    Log("ExecuteHtml: " & Query)
    If Limit > 0 Then Limit = Min(Limit, cur.RowCount) Else Limit = cur.RowCount
    Dim sb As StringBuilder
    sb.Initialize
    sb.Append("<html><body>").Append(CRLF)
    sb.Append("<style type='text/css'>").Append(HtmlCSS).Append("</style>").Append(CRLF)
    sb.Append("<table><tr>").Append(CRLF)
    For i = 0 To cur.ColumnCount - 1
        sb.Append("<th>").Append(cur.GetColumnName(i)).Append("</th>")
    Next
   
'    For i = 0 To cur.ColumnCount - 1
'        If i = 1 Then
'            sb.Append("<th style='width:200px;'>").Append(cur.GetColumnName(i)).Append("</th>")
'        Else
'            sb.Append("<th>").Append(cur.GetColumnName(i)).Append("</th>")
'        End If
'    Next
       
    sb.Append("</tr>").Append(CRLF)
    For row = 0 To Limit - 1
        cur.Position = row
        If row Mod 2 = 0 Then
            sb.Append("<tr>")
        Else
            sb.Append("<tr class='odd'>")
        End If
        For i = 0 To cur.ColumnCount - 1
            sb.Append("<td>")
            If Clickable Then
                sb.Append("<a href='http://").Append(i).Append(".")
                sb.Append(row)
                sb.Append(".com'>").Append(cur.GetString2(i)).Append("</a>")
            Else
                sb.Append(cur.GetString2(i))
            End If
            sb.Append("</td>")
        Next
        sb.Append("</tr>").Append(CRLF)
    Next
    cur.Close
    sb.Append("</table></body></html>")
    Return sb.ToString
End Sub

'Gets the current version of the database. If the DBVersion table does not exist it is created and the current
'version is set to version 1.
Public Sub GetDBVersion (SQL As SQL) As Int
    Dim count, version As Int
    count = SQL.ExecQuerySingleResult("SELECT count(*) FROM sqlite_master WHERE Type='table' AND name='DBVersion'")
    If count > 0 Then
        version = SQL.ExecQuerySingleResult("SELECT version FROM DBVersion")
    Else
        'Create the versions table.
        Dim m As Map
        m.Initialize
        m.Put("version", DB_INTEGER)
        CreateTable(SQL, "DBVersion", m, "version")
       
        SQL.ExecNonQuery("INSERT INTO DBVersion VALUES (1)")
       
        version = 1
    End If
   
    Return version
End Sub

'Sets the database version to the given version number.
Public Sub SetDBVersion (SQL As SQL, Version As Int)
    SQL.ExecNonQuery2("UPDATE DBVersion set version = ?", Array As Object(Version))
End Sub

' deletes a record
Public Sub DeleteRecord(SQL As SQL, TableName As String, WhereFieldEquals As Map)
    Dim sb As StringBuilder
    sb.Initialize
    sb.Append("DELETE FROM [").Append(TableName).Append("] WHERE ")
    If WhereFieldEquals.Size = 0 Then
        Log("WhereFieldEquals map empty!")
        Return
    End If
    Dim args As List
    args.Initialize
    For i = 0 To WhereFieldEquals.Size - 1
        If i > 0 Then sb.Append(" AND ")
        sb.Append("[").Append(WhereFieldEquals.GetKeyAt(i)).Append("] = ?")
        args.Add(WhereFieldEquals.GetValueAt(i))
    Next
    Log("DeleteRecord: " & sb.ToString)
    SQL.ExecNonQuery2(sb.ToString, args)
End Sub

Sub Process_Globals
   'These global variables will be declared once when the application starts.
   'These variables can be accessed from all modules.
   Public sql As SQL
   Public rp As RuntimePermissions
   Dim tablefound As Boolean = False

End Sub


Sub Service_Create
    'This is the program entry point.
    'This is a good place to load resources that are not specific to a single activity.
    Dim pth As String
    If File.Exists(DBUtils.GetDBFolder,"nw05.sqlite") = False Then
        Log(".sqlite Datei nicht vorhanden...")
        pth = DBUtils.CopyDBFromAssets("nw05.sqlite")
        sql.Initialize(pth, "nw05.sqlite", True)
    Else
        Log(".sqlite Datei vorhanden...")
        sql.Initialize(DBUtils.GetDBFolder, "nw05.sqlite", True)
    End If