[大数据]ServiceStack.OrmLite使用

因为在仿真建模的过程中，希望把运行过程传递给数据可视化的控制台显示出来，约定了以离线SQLite文件最为我们的数据接口。所以考虑到用ServiceStack.OrmLite来写数据到SQLite中。

步骤如下：

1. 在NuGet中安装Service Stack.OrmLite和ServiceStack.OrmLite.Sqlite包
2. 创建数据结构和表的映射关系

    class Foo
    {
    	[AutoIncrement]
        public int Id { get; set; }
        
        [CustomField("INT")]
        public int Idx { get; set; }

        [CustomField("CHAR(20)")]
        public string? Name { get; set; }

        [CustomField("CHAR(20)")]
        public string? CharColumn { get; set; }

        [CustomField("DECIMAL(18,4)")] 
        public decimal? DecimalColumn { get; set; }
        
		public void PrintDump()
        {
            Console.WriteLine($"Id={Id}, Name={Name}");
        }
    }

3. 创建数据库访问接口

class DvSQLite
    {
        public static string SqliteFileDb = String.Format($"~/AppData/SQLiteDbTest.sqlite").MapAbsolutePath();
        static OrmLiteConnectionFactory dbFactory = new OrmLiteConnectionFactory(SqliteFileDb, SqliteDialect.Provider);
        private IDbConnection _db;
        public DvSQLite()
        {
            _db = dbFactory.Open();
            _db.CreateTable<Foo>(true);
        }
		
		public void InsertFoo(Foo foo)
        {
            _db.Insert<Foo>(foo);
        }
		
		public Foo SelectFoo(int idx)
		{
			var result = _db.SingleById<Foo>(idx);
            result.PrintDump();
		}
    }

4. 使用

	private static DvSQLite _dvSQLite = new DvSQLite();
	_dvSQLite.InsertFoo(new Foo{Idx = 1, Name = "name"});
	_dvSQLite.SelectFoo(1);