Uno.sqlite-net/README.md

WebAssembly port of SQLite-net

This repository is a fork of the SQLite-net repository to add support for WebAssembly, using the Uno.SQLite-wasm package.

This is a work in progress.

Testing the library

• Open the SQLite solution
• Build the SQLite.Tests.Wasm project
• Using WSL, go the dist folder that was created in the bin\Debug folder
• Run a web server using python3 server.py
• Navigate to http://localhost:8000
• Observe the results in the browser's debugger window

TODO

• Make all the tests pass
• Publish a proper nuget package
• Integrate the WebAssembly TFM when https://github.com/NuGet/NuGet.Client/pull/2159 will be available.
• Cleanup and merge back to Frank's repo

Original documentation

Use one of these packages:

Version	Package	Description
	sqlite-net-pcl	.NET Standard Library
	sqlite-net-sqlcipher	With Encryption Support

SQLite-net is an open source, minimal library to allow .NET, .NET Core, and Mono applications to store data in SQLite 3 databases. It was first designed to work with Xamarin.iOS, but has since grown up to work on all the platforms (Xamarin.*, .NET, UWP, Azure, etc.).

SQLite-net was designed as a quick and convenient database layer. Its design follows from these goals:

• Very easy to integrate with existing projects and runs on all the .NET platforms.

• Thin wrapper over SQLite that is fast and efficient. (This library should not be the performance bottleneck of your queries.)

• Very simple methods for executing CRUD operations and queries safely (using parameters) and for retrieving the results of those query in a strongly typed fashion.

• Works with your data model without forcing you to change your classes. (Contains a small reflection-driven ORM layer.)

Nuget Installation

Install SQLite-net PCL from nuget.

Important: You will need to add the nuget package to both your PCL project and your platform-dependent project.

Source Installation

SQLite-net is all contained in 1 file (I know, so cool right?) and is easy to add to your project. Just add SQLite.cs to your project, and you're ready to start creating tables.

Please Contribute!

This is an open source project that welcomes contributions/suggestions/bug reports from those who use it. If you have any ideas on how to improve the library, please post an issue here on github. Please check out the How to Contribute.

Example Time!

Please consult the Wiki for, ahem, complete documentation.

The library contains simple attributes that you can use to control the construction of tables. In a simple stock program, you might use:

public class Stock
{
	[PrimaryKey, AutoIncrement]
	public int Id { get; set; }
	public string Symbol { get; set; }
}

public class Valuation
{
	[PrimaryKey, AutoIncrement]
	public int Id { get; set; }
	[Indexed]
	public int StockId { get; set; }
	public DateTime Time { get; set; }
	public decimal Price { get; set; }
}

Once you've defined the objects in your model you have a choice of APIs. You can use the "synchronous API" where calls block one at a time, or you can use the "asynchronous API" where calls do not block. You may care to use the asynchronous API for mobile applications in order to increase reponsiveness.

Both APIs are explained in the two sections below.

Synchronous API

Once you have defined your entity, you can automatically generate tables in your database by calling CreateTable:

// Get an absolute path to the database file
var databasePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "MyData.db");

var db = new SQLiteConnection(databasePath);
db.CreateTable<Stock>();
db.CreateTable<Valuation>();

You can insert rows in the database using Insert. If the table contains an auto-incremented primary key, then the value for that key will be available to you after the insert:

public static void AddStock(SQLiteConnection db, string symbol) {
	var s = db.Insert(new Stock() {
		Symbol = symbol
	});
	Console.WriteLine("{0} == {1}", s.Symbol, s.Id);
}

Similar methods exist for Update and Delete.

The most straightforward way to query for data is using the Table method. This can take predicates for constraining via WHERE clauses and/or adding ORDER BY clauses:

var conn = new SQLiteConnection(databasePath);
var query = conn.Table<Stock>().Where(v => v.Symbol.StartsWith("A"));

foreach (var stock in query)
	Debug.WriteLine("Stock: " + stock.Symbol);

You can also query the database at a low-level using the Query method:

public static IEnumerable<Valuation> QueryValuations (SQLiteConnection db, Stock stock) {
	return db.Query<Valuation> ("select * from Valuation where StockId = ?", stock.Id);
}

The generic parameter to the Query method specifies the type of object to create for each row. It can be one of your table classes, or any other class whose public properties match the column returned by the query. For instance, we could rewrite the above query as:

public class Val
{
	public decimal Money { get; set; }
	public DateTime Date { get; set; }
}

public static IEnumerable<Val> QueryVals (SQLiteConnection db, Stock stock) {
	return db.Query<Val> ("select \"Price\" as \"Money\", \"Time\" as \"Date\" from Valuation where StockId = ?", stock.Id);
}

You can perform low-level updates of the database using the Execute method.

Asynchronous API

The asynchronous library uses the Task Parallel Library (TPL). As such, normal use of Task objects, and the async and await keywords will work for you.

Once you have defined your entity, you can automatically generate tables by calling CreateTableAsync:

// Get an absolute path to the database file
var databasePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "MyData.db");

var conn = new SQLiteAsyncConnection(databasePath);

await conn.CreateTableAsync<Stock>();

Debug.WriteLine("Table created!");

You can insert rows in the database using Insert. If the table contains an auto-incremented primary key, then the value for that key will be available to you after the insert:

Stock stock = new Stock()
{
	Symbol = "AAPL"
};

var conn = new SQLiteAsyncConnection(databasePath);

await conn.InsertAsync(stock);

Debug.WriteLine("New customer ID: {0}", stock.Id);

Similar methods exist for UpdateAsync and DeleteAsync.

Querying for data is most straightforwardly done using the Table method. This will return an AsyncTableQuery instance back, whereupon you can add predictates for constraining via WHERE clauses and/or adding ORDER BY. The database is not physically touched until one of the special retrieval methods - ToListAsync, FirstAsync, or FirstOrDefaultAsync - is called.

var conn = new SQLiteAsyncConnection(databasePath);
var query = await conn.Table<Stock>().Where(v => v.Symbol.StartsWith("A"));

var result = await query.ToListAsync();

foreach (var stock in result)
	Debug.WriteLine("Stock: " + stock.Symbol);

There are a number of low-level methods available. You can also query the database directly via the QueryAsync method. Over and above the change operations provided by InsertAsync etc you can issue ExecuteAsync methods to change sets of data directly within the database.

Another helpful method is ExecuteScalarAsync. This allows you to return a scalar value from the database easily:

var conn = new SQLiteAsyncConnection(databasePath);

var result = await conn.ExecuteScalarAsync<int>("select count(*) from Stock");

Debug.WriteLine(string.Format("Found '{0}' stock items.", result));

Using SQLCipher

You can add support for encrypted databases using SQLCipher by including an additional package SQLitePCLRaw.bundle_sqlcipher.

I'll let Eric Sink explain how to use SQLCipher with SQLite-net:

The reference to bundle_sqlcipher must be placed in your app project. What happens here is that SQLite-net references bundle_green, but at build time, bundle_sqlcipher gets substituted in its place.

Thank you!

Thank you to the .NET community for embracing this project, and thank you to all the contributors who have helped to make this great.

Thanks also to Tirza van Dijk (@tirzavdijk) for the great logo!