This library allows the use of asynchronous programming techniques with the LiteDb library. It is intended for Xamarin and WPF applications that require or would benefit a lightweight NoSQL database but also don't want to open and manage lots of threads or block the UI while database operations are occuring.
We manage the thread for you.
Available on nuget. https://www.nuget.org/packages/LiteDB.Async/
Include the nuget package in your project in the usual way
Install-Package LiteDB.Async
or
dotnet add package LiteDB.Async
Open a LiteDbAsync instance by calling the constructor in the standard way.
var db = new LiteDatabaseAsync("Filename=mydatabase.db;Connection=shared;Password=hunter2");
Collections are the equivalent of tables
var collection = _db.GetCollection<SimplePerson>();
This will give us an instance of the collection we can read and write.
We can upsert just like in the regular LiteDb
var collection = _db.GetCollection<SimplePerson>();
var person = new SimplePerson()
{
Id = Guid.NewGuid(),
FirstName = "John",
LastName = "Smith"
};
var upsertResult = await collection.UpsertAsync(person);
When we want to read from the database we should use a query.
To read all SimplePerson's in the database
var collection = _db.GetCollection<SimplePerson>();
var listResult = await collection.Query().ToListAsync();
You can use Linq
var theSmiths = await collection.Query().Where(x => x.Lastname == "Smith").ToListAsync();
Use the BeginTransaction method to start a transaction
using var asyncDb1 = new LiteDatabaseAsync(connectionString);
using var asyncDb2 = await asyncDb1.BeginTransactionAsync();
Operations run on asyncDb2 are now isolated from asyncDb1. They can also be rolled back, or if your program exits without call CommitAsync they are lost.
From version 5.0.16 of LiteDb we started to have problems with transactions on Shared connections. Therefore will be recommending Direct connections from LiteDb.Async version 0.1.6 goind forward.
To commit
await asyncDb2.CommitAsync();
Almost all functions from LiteDb have an async replacement
From Collections
Query, CountAsync, LongCountAsync, ExistsAsync, MinAsync, MaxAsync, DeleteAsync, DeleteManyAsync, FindAsync, FindByIdAsync, FindOneAsync, FindAllAsync, Include, EnsureIndexAsync, InsertAsync, UpdateAsync, UpdateManyAsync, UpsertAsync
From Query
Include, Where, OrderBy, OrderByDescending, GroupBy, Select, Limit, Skip, Offset, ForUpdate, ToDocumentsAsync, ToEnumerableAsync, ToListAsync, ToArrayAsync, FirstAsync, FirstOrDefaultAsync, SingleAsync, SingleOrDefaultAsync, CountAsync, LongCountAsync, ExistsAsync
From Database
UtcDate, CheckpointSize, UserVersion, Timeout, Collation, LimitSize, BeginTransAsync, CommitAsync, RollbackAsync, PragmaAsync, GetCollectionNamesAsync, CollectionExistsAsync, DropCollectionAsync, RenameCollectionAsync, CheckpointAsync, RebuildAsync
From Storage
The constructor LiteDatabaseAsync opens and wraps a LiteDB instant. It also starts a background thread which all actions are performed in.
When a function that causes an evaluation is called it sends a message to the background thread, where the required action is performed by the LiteDb instance. The result is then return to the calling thread when the function in the background completes. If the function in the background thread causes an exception it is caught and a LiteAsyncException is raised. The original exception is preserved as the InnerException.
Each class or interface in the LiteDb library has an equivalent in the LiteDb.Async library. Each function that returns a task is named with the async suffix. You can then call LiteDb.ASync methods using similar syntax to calling async functions in EF Core.
A new database object is created and connects to the same source, the new database object also creates a new background worker thread for itself. It then calls the underlying LiteDb.BeginTrans function to use LiteDb's transaction functionality.
To build the solution
dotnet build
To run the unit tests
dotnet test
To run a single specific unit test
dotnet test --filter DisplayName=LiteDB.Async.Test.SimpleDatabaseTest.TestCanUpsertAndGetList
To build for nuget
dotnet pack --configuration Release
Don't forget to bump the version number in the litedbasync.csproj project file
It will build a nupkg file.
Next log in to nuget.org and upload the nupkg file which was just built.
Done the package will be available to the world within a few minutes.
https://docs.microsoft.com/en-us/nuget/quickstart/create-and-publish-a-package-using-the-dotnet-cli
https://docs.microsoft.com/en-us/nuget/nuget-org/publish-a-package
When checking out for the first time copy the .vscode/launch.json.default and .vscode/tasks.json.default to .vscode/launch.json and .vscode/tasks.json.
The repo https://github.com/mlockett42/mvvm-cross-litedb-async gives an example of how to use this library in Xamarin Forms and MVVM.