Local Database using json idea

Probably has again to do with endofline. If the server runs on Windows and the client runs on a Mac, the expected endoflines are different.

Real machine, and yep ping ok.
The client send button is enabled on entry.
In the next few days i hope to get a basic4android version up and going as well.

Can I make it to work with both, or do I need different versions for both.
what if the server is a Mac and client a PC or even an Android (using B4A)


Change both the client & the server to use ChrB(26) as the terminator. This in the old days was end-of-file. You can use + Z to emulate this when using Telnet.

Updated versions Client & Server

Thanks so much for that will give it a test.
BTW might that fix the blob field that I tested but did not work?

No, if you want to transfer blobs you’ll need to use encodehex for that column at the server & decodehex at the client.

I’d just like to make this plain to anyone looking here - this project is a demo of the power of Xojo. If it were ever to make it to the wild there would be chaos - there is absolutely no security on access and no reasonable expectation that this could be added without significant cost.

Point taken.
As it is now, it would only be Intranet, is that correct?


And works like a charm from the PC as a server and Client as the mac.
Intranet only.


On an Intranet there’s a reasonable expectation of security, however with BYOD you can never be sure.

Tom I’d never use this code commercially, it was always just a hack to show the power & ease of using Xojo.

Point taken.
Will only be used in-house.
And thanks again for your help.
BTW works like a charm with the PC as a server and Mac as the client.

Have added blowfish encoding now. Works well.
For multiple connections do I need a separate socket on the server side for each connection?
If so how do I implement this.
Maybe have a few connections listening. Am at a loss.


Have a look at ServerSocket. It basically listens on the selected port and then “hands-off” the connection to one of a pool of TCPSockets.

Thanks I will. Do I still only use 1 port?

Thanks Wayne,
Works like a charm I think.
Did some copying and pasting from the demo.
Will check some more now.

Hi All and I hope Wayne,
I am still using Wayne’s Json Client Server.
I have added to the sqlite database and have some Date Fields.
Some of these are nil, I have not given all the Date fields a value.
When I run the server I get an error when I try and get all the fields from a record.
The error is

Exception Message: Unrecognized Object: 0 Exception Error Number: 11
This is set on
Return Result.ToString

I assume this is because of a nill object.
How can I catch this or do I have to set all dates to a specific value?
When I insert into the database I first check if the object is nil then I don’t include that field.
I would love to do that on the sending side.


Hi Tom

You can test if the field is Nil with “.value Is Nil”


Tried that and got errors.
Have done this…

    Dim rst As RecordSet = MyDatabase.SQLSelect(rs.Value("sql"))
    Dim Result As New JSONItem
    If MyDatabase.Error Then
      Result.Value("Error") = True
      Result.Value("ErrorMessage") = MyDatabase.ErrorMessage
      Result.Value("Error") = False
      Dim jRecordSet As New JSONItem
      If rst = Nil Then ' rst will be nil if the Request wasn't a query
        Do Until rst.EOF
          Dim js As New JSONItem
          For i = 1 To rst.FieldCount
            if rst.IdxField(i).Name = "image" then
              js.Value(rst.IdxField(i).Name) = encodebase64(rst.IdxField(i).Value)
              if rst.ColumnType(i)=8 then // Date
                dim d1 as new Date
                if rst.Field(rst.IdxField(i).Name).DateValue = nil then
                  d.Year = 1949
                  js.Value(rst.IdxField(i).Name) = d.SQLDate
                  js.Value(rst.IdxField(i).Name) = rst.IdxField(i).Value
                end if
                js.Value(rst.IdxField(i).Name) = rst.IdxField(i).Value
              end If
            end if
          Next i
          jRecordSet.Append js
      End If

but get a unsupported value here
if rst.Field(rst.IdxField(i).Name).DateValue = nil then

Only happens on Date field

strange though.
I did another test to see if would work…

        if rs.ColumnType(7)=8 then
          if rs.Field("lastupdate").DateValue <> nil then
            d = rs.Field("lastupdate").DateValue
             label1.Text = d.ShortDate
          end if
        end if

And no exception happens.

Just changed the ColumnType to i-1 and it passed that
but came up with another error
Unrecognized Object: 0

Maybe it is the Currency being null as well.
Will check