SqliteDatabaseContext.cs

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using System;
using System.Linq;
 
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
 
using Tgstation.Server.Host.Configuration;
 
namespace Tgstation.Server.Host.Database
{
    sealed class SqliteDatabaseContext : DatabaseContext
    {
        readonly bool designTime;
 
        public SqliteDatabaseContext(
            DbContextOptions<SqliteDatabaseContext> dbContextOptions)
            : this(dbContextOptions, false)
        {
        }
 
        internal SqliteDatabaseContext(
            DbContextOptions<SqliteDatabaseContext> dbContextOptions,
            bool designTime)
            : base(dbContextOptions)
        {
            this.designTime = designTime;
        }
 
        public static void ConfigureWith(
            DbContextOptionsBuilder options,
            DatabaseConfiguration databaseConfiguration)
        {
            ArgumentNullException.ThrowIfNull(options);
            ArgumentNullException.ThrowIfNull(databaseConfiguration);
 
            if (databaseConfiguration.DatabaseType != DatabaseType.Sqlite)
                throw new InvalidOperationException($"Invalid DatabaseType for {nameof(SqliteDatabaseContext)}!");
 
            options.UseSqlite(databaseConfiguration.ConnectionString, sqliteOptions => sqliteOptions.UseQuerySplittingBehavior(QuerySplittingBehavior.SingleQuery));
        }
 
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
 
            // Shamelessly stolen from https://blog.dangl.me/archive/handling-datetimeoffset-in-sqlite-with-entity-framework-core/
 
            // SQLite does not have proper support for DateTimeOffset via Entity Framework Core, see the limitations
            // here: https://docs.microsoft.com/en-us/ef/core/providers/sqlite/limitations#query-limitations
            // To work around this, when the Sqlite database provider is used, all model properties of type DateTimeOffset
            // use the DateTimeOffsetToBinaryConverter
            // Based on: https://github.com/aspnet/EntityFrameworkCore/issues/10784#issuecomment-415769754
            // This only supports millisecond precision, but should be sufficient for most use cases.
            if (!designTime)
                foreach (var entityType in modelBuilder.Model.GetEntityTypes())
                {
                    var properties = entityType
                        .ClrType
                        .GetProperties()
                        .Where(p => p.PropertyType == typeof(DateTimeOffset) || p.PropertyType == typeof(DateTimeOffset?));
                    foreach (var property in properties)
                        modelBuilder
                            .Entity(entityType.Name)
                            .Property(property.Name)
                            .HasConversion(new DateTimeOffsetToBinaryConverter());
                }
        }
    }
}