為了避免因?yàn)閿?shù)據(jù)庫(kù)查詢產(chǎn)生測(cè)試結(jié)果的差異，我們這里使用內(nèi)存數(shù)據(jù)庫(kù)，它開銷更小，同時(shí)也可以避免數(shù)據(jù)庫(kù)優(yōu)化執(zhí)行計(jì)劃以及緩存所帶來(lái)的問題。

實(shí)體定義以前數(shù)據(jù)庫(kù)DbContext

定義實(shí)體

在這我們定義一個(gè)Category實(shí)體類型，非常簡(jiǎn)單，只有兩個(gè)屬性。

    public class Category
    {
        public Guid Id { get; set; }
        public string Name { get; set; }
    }

數(shù)據(jù)庫(kù)DbContext

在FillCategories方法中，將內(nèi)存數(shù)據(jù)庫(kù)中增加三條記錄。

    public class TestDbContext : DbContext
    {
        public TestDbContext(DbContextOptions<TestDbContext> options) : base(options)
        {
        }

        public DbSet<Category> Categories { get; set; }

        public void FillCategories()
        {
            var foodCategory = new Category {
                Id = Guid.NewGuid(),
                Name = "Food"
            };

            Categories.AddRange(foodCategory, new Category {
                Id = Guid.NewGuid(),
                Name = "Drinks"
            }, new Category {
                Id = Guid.NewGuid(),
                Name = "Clothing"
            }, new Category {
                Id = Guid.NewGuid(),
                Name = "Electronis"
            });


            SaveChanges(true);
        }
    }

測(cè)試代碼

    public class CompileQueryTest
    {
        private   Func<TestDbContext, Guid, Category> _getCategory =
            EF.CompileQuery((TestDbContext context, Guid id) => context.Categories.FirstOrDefault(c => c.Id == id));

        private readonly TestDbContext _dbContext;

        public CompileQueryTest()
        {
            var options = new DbContextOptionsBuilder<TestDbContext>().UseInMemoryDatabase(Guid.NewGuid().ToString()).Options;
            var context = new TestDbContext(options);

            context.FillCategories();

            _dbContext = context;
        }

        private readonly Guid _queryId = Guid.NewGuid();

        [Benchmark]
        public void CompiledQuery()
        {
            _ = _getCategory(_dbContext, _queryId);
        }


        [Benchmark]
        public void UnCompiledQuery()
        {

            _ = _dbContext.Categories.FirstOrDefault(c => c.Id == _queryId);

        }
    }

為了更加接近測(cè)試結(jié)果，我們?cè)跇?gòu)造函數(shù)中創(chuàng)建TestDbContext對(duì)象以及填充數(shù)據(jù)庫(kù)。