👩🏿‍🤝‍👨🏻 🚪 ♂️ Beberapa aspek mengoptimalkan kueri LINQ di C # .NET untuk MS SQL Server 🉐 😞 🐅

LINQ telah memasuki .NET sebagai bahasa manipulasi data baru yang kuat. LINQ ke SQL sebagai bagian darinya memungkinkan Anda untuk berkomunikasi dengan DBMS menggunakan misalnya Entity Framework. Namun, cukup sering menggunakannya, pengembang lupa untuk melihat permintaan SQL tertentu yang akan dihasilkan oleh penyedia yang dapat ditanyakan, dalam kasus Anda, Kerangka Entitas.

Mari kita menganalisis dua poin utama menggunakan contoh.
Untuk melakukan ini, buat database Uji di SQL Server, dan buat dua tabel di dalamnya menggunakan kueri berikut:

Buat tabel

USE [TEST]
GO

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Ref](
	[ID] [int] NOT NULL,
	[ID2] [int] NOT NULL,
	[Name] [nvarchar](255) NOT NULL,
	[InsertUTCDate] [datetime] NOT NULL,
 CONSTRAINT [PK_Ref] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[Ref] ADD  CONSTRAINT [DF_Ref_InsertUTCDate]  DEFAULT (getutcdate()) FOR [InsertUTCDate]
GO

USE [TEST]
GO

SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[Customer](
	[ID] [int] NOT NULL,
	[Name] [nvarchar](255) NOT NULL,
	[Ref_ID] [int] NOT NULL,
	[InsertUTCDate] [datetime] NOT NULL,
	[Ref_ID2] [int] NOT NULL,
 CONSTRAINT [PK_Customer] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[Customer] ADD  CONSTRAINT [DF_Customer_Ref_ID]  DEFAULT ((0)) FOR [Ref_ID]
GO

ALTER TABLE [dbo].[Customer] ADD  CONSTRAINT [DF_Customer_InsertUTCDate]  DEFAULT (getutcdate()) FOR [InsertUTCDate]
GO

Ref :

Ref

USE [TEST]
GO

DECLARE @ind INT=1;

WHILE(@ind<1200000)
BEGIN
	INSERT INTO [dbo].[Ref]
           ([ID]
           ,[ID2]
           ,[Name])
    SELECT
           @ind
           ,@ind
           ,CAST(@ind AS NVARCHAR(255));

	SET @ind=@ind+1;
END 
GO

Customer :

Customer

USE [TEST]
GO

DECLARE @ind INT=1;
DECLARE @ind_ref INT=1;

WHILE(@ind<=12000000)
BEGIN
	IF(@ind%3=0) SET @ind_ref=1;
	ELSE IF (@ind%5=0) SET @ind_ref=2;
	ELSE IF (@ind%7=0) SET @ind_ref=3;
	ELSE IF (@ind%11=0) SET @ind_ref=4;
	ELSE IF (@ind%13=0) SET @ind_ref=5;
	ELSE IF (@ind%17=0) SET @ind_ref=6;
	ELSE IF (@ind%19=0) SET @ind_ref=7;
	ELSE IF (@ind%23=0) SET @ind_ref=8;
	ELSE IF (@ind%29=0) SET @ind_ref=9;
	ELSE IF (@ind%31=0) SET @ind_ref=10;
	ELSE IF (@ind%37=0) SET @ind_ref=11;
	ELSE SET @ind_ref=@ind%1190000;
	
	INSERT INTO [dbo].[Customer]
	           ([ID]
	           ,[Name]
	           ,[Ref_ID]
	           ,[Ref_ID2])
	     SELECT
	           @ind,
	           CAST(@ind AS NVARCHAR(255)),
	           @ind_ref,
	           @ind_ref;


	SET @ind=@ind+1;
END
GO

, 1 , - 10 .

Visual Studio Visual C# Console App (.NET Framework):

, Entity Framework.
, Manage NuGet Packages:

NuGet- «Entity Framework» Entity Framework :

App.config configSections :

<connectionStrings>
    <add name="DBConnection" connectionString="data source=__MSSQL;Initial Catalog=TEST;Integrated Security=True;" providerName="System.Data.SqlClient" />
</connectionStrings>

connectionString .

3 :

IBaseEntityID

namespace TestLINQ
{
    public interface IBaseEntityID
    {
        int ID { get; set; }
    }
}

IBaseEntityName

namespace TestLINQ
{
    public interface IBaseEntityName
    {
        string Name { get; set; }
    }
}

IBaseNameInsertUTCDate

namespace TestLINQ
{
    public interface IBaseNameInsertUTCDate
    {
        DateTime InsertUTCDate { get; set; }
    }
}

BaseEntity , :

BaseEntity

namespace TestLINQ
{
    public class BaseEntity : IBaseEntityID, IBaseEntityName, IBaseNameInsertUTCDate
    {
        public int ID { get; set; }
        public string Name { get; set; }
        public DateTime InsertUTCDate { get; set; }
    }
}

Ref

using System.ComponentModel.DataAnnotations.Schema;

namespace TestLINQ
{
    [Table("Ref")]
    public class Ref : BaseEntity
    {
        public int ID2 { get; set; }
    }
}

Customer

using System.ComponentModel.DataAnnotations.Schema;

namespace TestLINQ
{
    [Table("Customer")]
    public class Customer: BaseEntity
    {
        public int Ref_ID { get; set; }
        public int Ref_ID2 { get; set; }
    }
}

UserContext:

UserContex

using System.Data.Entity;

namespace TestLINQ
{
    public class UserContext : DbContext
    {
        public UserContext()
            : base("DbConnection")
        {
            Database.SetInitializer<UserContext>(null);
        }

        public DbSet<Customer> Customer { get; set; }
        public DbSet<Ref> Ref { get; set; }
    }
}

LINQ to SQL EF MS SQL Server:

Program.cs :

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace TestLINQ
{
    class Program
    {
        static void Main(string[] args)
        {
            using (UserContext db = new UserContext())
            {
                var dblog = new List<string>();
                db.Database.Log = dblog.Add;

                var query = from e1 in db.Customer
                            from e2 in db.Ref
                            where (e1.Ref_ID == e2.ID)
                                 && (e1.Ref_ID2 == e2.ID2)
                            select new { Data1 = e1.Name, Data2 = e2.Name };

                var result = query.Take(1000).ToList();

                Console.WriteLine(dblog[1]);

                Console.ReadKey();
            }
        }
    }
}

.

:

SQL-

SELECT TOP (1000) 
    [Extent1].[Ref_ID] AS [Ref_ID], 
    [Extent1].[Name] AS [Name], 
    [Extent2].[Name] AS [Name1]
    FROM  [dbo].[Customer] AS [Extent1]
    INNER JOIN [dbo].[Ref] AS [Extent2] ON ([Extent1].[Ref_ID] = [Extent2].[ID]) AND ([Extent1].[Ref_ID2] = [Extent2].[ID2])

. . LINQ- SQL- MS SQL Server.

LINQ-:

LINQ-

var query = from e1 in db.Customer
                            from e2 in db.Ref
                            where (e1.Ref_ID == e2.ID)
                                || (e1.Ref_ID2 == e2.ID2)
                            select new { Data1 = e1.Name, Data2 = e2.Name };

.

, 30 :

LINQ:

, , ():

SQL-

SELECT TOP (1000) 
    [Extent1].[Ref_ID] AS [Ref_ID], 
    [Extent1].[Name] AS [Name], 
    [Extent2].[Name] AS [Name1]
    FROM  [dbo].[Customer] AS [Extent1]
    CROSS JOIN [dbo].[Ref] AS [Extent2]
    WHERE [Extent1].[Ref_ID] = [Extent2].[ID] OR [Extent1].[Ref_ID2] = [Extent2].[ID2]

LINQ- :

LINQ-

var query = (from e1 in db.Customer
                   join e2 in db.Ref
                   on e1.Ref_ID equals e2.ID
                   select new { Data1 = e1.Name, Data2 = e2.Name }).Union(
                        from e1 in db.Customer
                        join e2 in db.Ref
                        on e1.Ref_ID2 equals e2.ID2
                        select new { Data1 = e1.Name, Data2 = e2.Name });

SQL-:

SQL-

SELECT 
    [Limit1].[C1] AS [C1], 
    [Limit1].[C2] AS [C2], 
    [Limit1].[C3] AS [C3]
    FROM ( SELECT DISTINCT TOP (1000) 
        [UnionAll1].[C1] AS [C1], 
        [UnionAll1].[Name] AS [C2], 
        [UnionAll1].[Name1] AS [C3]
        FROM  (SELECT 
            1 AS [C1], 
            [Extent1].[Name] AS [Name], 
            [Extent2].[Name] AS [Name1]
            FROM  [dbo].[Customer] AS [Extent1]
            INNER JOIN [dbo].[Ref] AS [Extent2] ON [Extent1].[Ref_ID] = [Extent2].[ID]
        UNION ALL
            SELECT 
            1 AS [C1], 
            [Extent3].[Name] AS [Name], 
            [Extent4].[Name] AS [Name1]
            FROM  [dbo].[Customer] AS [Extent3]
            INNER JOIN [dbo].[Ref] AS [Extent4] ON [Extent3].[Ref_ID2] = [Extent4].[ID2]) AS [UnionAll1]
    )  AS [Limit1]

, LINQ- , Union .
, , . , .

:

CROSS JOIN 195 :
INNER JOIN-UNION 24 :

.
Plans .

Beberapa aspek mengoptimalkan kueri LINQ di C # .NET untuk MS SQL Server

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