There are 2 options to use OctoDB on Xamarin:
- SQLite.NET
- Microsoft.Data.SQLite
The SQLite.NET for OctoDB is a fork of SQLite.NET that uses the OctoDB library
First follow the instructions to compile OctoDB for mobile or use the pre-compiled native libraries
You can start downloading the free version:
Add the native libraries to the project according to the platform
On Android you may have a folder structure like this:
- lib
- arm64-v8a
- armeabi-v7a
- x86
- x86_64
On each sub-folder you may have 4 libraries:
liboctodb.so
libuv.so
libbinn.so
libsecp256k1-vrf.so
For each of the .so files, CONTROL + CLICK then set Build Action to AndroidNativeLibrary
On iOS we should have 4 fat libraries for static linking:
liboctodb.a
libuv.a
libbinn.a
libsecp256k1-vrf.a
CONTROL + CLICK on the Xamarin.iOS project then choose Add > Add Native Reference and select the 4 libraries from the folder
CONTROL + CLICK on each library, click Properties and enable these items:
√ Force Load
√ Smart Link
Install with these commands:
dotnet add package SQLitePCLRaw.core --version 2.0.4
dotnet add package SQLitePCLRawProvider.static --version 2.0.4
dotnet add package SQLitePCLRawProvider.OctoDB --version 2.0.4
Add the SQLite.cs file to your project
And define the __MOBILE__ and USE_SQLITEPCL_RAW conditional variables in the main/shared project
The library contains simple attributes that you can use to control the construction of tables
public class TodoItem
{
[PrimaryKey, AutoIncrement]
public long ID { get; set; }
public string Name { get; set; }
public bool Done { get; set; }
}On tables with integer primary keys the primary key column must be declared as long instead of int because OctoDB always use a 64-bit number for row ids
using SQLite;
using SQLitePCL;
if (Device.RuntimePlatform == Device.iOS)
{
// use the OctoDB static native library
SQLitePCL.raw.SetProvider(new SQLite3Provider_static());
}
else // if (Device.RuntimePlatform == Device.Android)
{
// load the OctoDB dynamic native library
SQLitePCL.raw.SetProvider(new SQLite3Provider_OctoDB());
}
// open the database
var databasePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "App.db");
var uri = "file:" + databasePath + "?node=secondary&connect=tcp://123.45.67.89:1234";
var db = new SQLiteConnection(uri);
// check if the database is ready
if (db.IsReady()) {
// the user is already logged in. show the main screen
...
} else {
// the user is not logged in. show the login screen (and do not access the database!)
...
// wait until the login is successful
db.OnReady(() => {
// the log in was successful. show the main screen (the app can access the database now)
...
});
}
// subscribe to db sync notifications
db.OnSync(() => {
// update the screen with new data
...
});To retrieve the synchronization status:
var status = db.ExecuteScalar<string>("pragma sync_status");The Microsoft.Data.SQLite uses the SQLitePCLRaw to interface with the native library
First follow the instructions to compile OctoDB for mobile or use the pre-compiled native libraries. You can start downloading the free version:
Add the native libraries to the project according to the platform
On Android you may have a folder structure like this:
- lib
- arm64-v8a
- armeabi-v7a
- x86
- x86_64
On each sub-folder you may have 4 libraries:
liboctodb.so
libuv.so
libbinn.so
libsecp256k1-vrf.so
For each of the .so files, CONTROL + CLICK then set Build Action to AndroidNativeLibrary
On iOS we should have 4 fat libraries for static linking:
liboctodb.a
libuv.a
libbinn.a
libsecp256k1-vrf.a
CONTROL + CLICK on the Xamarin.iOS project then choose Add > Add Native Reference and select the 4 libraries from the folder
CONTROL + CLICK on each library, click Properties and enable these items:
√ Force Load
√ Smart Link
Install with these commands:
dotnet add package Microsoft.Data.Sqlite
dotnet add package Microsoft.Data.Sqlite.Core
dotnet add package SQLitePCLRaw.core --version 2.0.4
dotnet add package SQLitePCLRawProvider.static --version 2.0.4
dotnet add package SQLitePCLRawProvider.OctoDB --version 2.0.4
Make sure to load the native library before using Microsoft.Data.Sqlite
Also, avoid using a SQLitePCLRaw bundle package which might override the dynamic provider
using Microsoft.Data.Sqlite;
using SQLitePCL;
namespace OctoDBExample
{
class Program
{
static void Main()
{
if (Device.RuntimePlatform == Device.iOS)
{
// use the OctoDB static native library
SQLitePCL.raw.SetProvider(new SQLite3Provider_static());
}
else // if (Device.RuntimePlatform == Device.Android)
{
// load the OctoDB dynamic native library
SQLitePCL.raw.SetProvider(new SQLite3Provider_OctoDB());
}
SQLitePCL.raw.FreezeProvider(true);
// open the database
var uri = "file:test.db?node=primary&bind=tcp://0.0.0.0:1234";
var db = new SqliteConnection("Data Source=" + uri);
db.Open();
// check if the db is ready
while (true) {
SqliteCommand cmd = db.CreateCommand();
cmd.CommandText = "pragma sync_status";
string status = (string) cmd.ExecuteScalar();
if (status == null) {
Console.WriteLine("the loaded library does not contain OctoDB");
return;
}
if (status.Contains("\"db_is_ready\": true")) break;
System.Threading.Thread.Sleep(250);
}
// subscribe to db sync notifications
db.CreateFunction("sync_notification", () => {
// notification received on the worker thread - you can transfer it to the main thread here
Console.WriteLine("db sync received");
});
// now we can use the database
...
}
}
}