配置文件设置appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*",
  "ConnectionStrings": {
    "SQLiteConnection": "Filename=./sqlite.db3"
  }
}

Startup启动器中的配置服务中添加sqlite数据库上下文服务

services.AddDbContext<AppDbContext>(options => options.UseSqlite(Configuration.GetConnectionString("SQLiteConnection")));

ASP.NET Core配置SQLite数据库连接