[英]Why tolist takes too long for only 1 item?
我對 SQL Server 進行了存儲過程調用,並嘗試僅獲取 1 個項目。 數據庫立即返回,但是當我嘗試使用ToList()
時它運行速度非常慢
public partial class Product: BaseEntity, ISlugSupported
{
public string Name { get; set; }
public int ManufacturerId { get; set; }
public string Sku { get; set; }
public decimal Price { get; set; }
public bool InStock { get; set; }
public int StockQuantity { get; set; }
public decimal ProductCostInUSD { get; set; }
public decimal ProductCostInUSDOldPrice { get; set; }
public decimal ProductCostInPound { get; set; }
public decimal ProductCostInEuro { get; set; }
public decimal ProductCostInVND { get; set; }
public bool Published { get; set; }
public decimal ExchangeRateUSD { get; set; }
public decimal ExchangeRateEuro { get; set; }
public decimal ExchangeRatePound { get; set; }
public DateTime CreatedDate { get; set; }
public DateTime UpdatedDate { get; set; }
public string Createdby { get; set; }
public int Status { get; set; }
public int? CategoryId { get; set; }
}
存儲過程方法:
public class EFRepository<T> : IRepository<T> where T : BaseEntity
{
private readonly ApplicationDbContext _context;
private DbSet<T> _entities;
public EFRepository(ApplicationDbContext context)
{
this._context = context;
}
public IQueryable<T> ExecuteStoredProcedureList(string commandText, params object[] parameters)
{
return _context.Set<T>().FromSql(commandText, parameters);
}
}
數據庫上下文:
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
base.OnModelCreating(builder);
builder.Entity<Product>()
.ToTable("Product")
.Ignore(p => p.ProductFinalCost);
}
}
調用存儲過程:
var query = _productRepository.ExecuteStoredProcedureList("dbo.[SearchProducts] " +
"@Keywords, @PageIndex,@PageSize,@SortBy,@FromDate, @ToDate,@Sku,@CreateBy,@CategoryIds,@OrderIds,@ShowPublished,@Discontinued,@Discount,@LoadFilterableSpecificationAttributeOptionIds, @FilterableSpecificationAttributeOptionIds OUTPUT,@PriceMin,@PriceMax,@ShowExpiredProduct,@FilterableBrands OUTPUT,@TotalRecords OUTPUT,@FilteredSpecs, @FilteredBrands,@LoadSimple,@TrungvangPick",
pKeywords,
pPageIndex,
pPageSize,
pSortBy,
pFromDate,
pToDate,
pSku,
pCreatedBy,
pCategoryIds,
pOrderIds,
pShowPublished,
pDiscontinued,
pDiscount,
pLoadFilterableSpecificationAttributeOptionIds,
pFilterableSpecificationAttributeOptionIds,
pPriceMin,
pPriceMax,
pShowExpiredProduct,
pFilterableBrands,
pTotalRecords,
pFilteredSpecs,
pFilteredBrands,
pLoadSimple,
pTrungvangPick
);
var result = query.ToList();
int totalRecords = pTotalRecords.Value != DBNull.Value ? Convert.ToInt32(pTotalRecords.Value) : 0;
SQL Server 中的存儲過程立即返回,因此這不是存儲過程問題(在數據庫上直接測試運行)。
正如您從 var 結果點到下一個命令所看到的,僅包含幾個數字字段的 1 個簡單項目ProductSimple
最多需要 467 毫秒,我嘗試來回移動調試點以檢查速度,它仍然保持在相同的時間。
在另一個項目中,此ToList()
對於相同的項目結構轉換非常快。 我可能做錯了什么?
我正在使用 ASP.NET Core 2.2.4 和 EF Core 2.2.4
查詢不會立即返回。 在 .ToList 調用之前,查詢實際上不會執行。
查詢返回所需的時間取決於連接到數據庫的時間以及查詢的效率。
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