I-LINQ ifake i-.NET njengolimi olusha olunamandla lokukhohlisa idatha. I-LINQ kuya ku-SQL njengengxenye yayo ikuvumela ukuthi uxhumane kalula ne-DBMS usebenzisa, isibonelo, i-Entity Framework. Kodwa-ke, uma beyisebenzisa kaningi, abathuthukisi bayakhohlwa ukubheka ukuthi hlobo luni lombuzo we-SQL umhlinzeki ongabuzwa, esimweni sakho I-Entity Framework, azoyenza.
Ake sibheke amaphuzu amabili abalulekile sisebenzisa isibonelo.
Ukuze wenze lokhu, dala isizindalwazi sokuhlola ku-SQL Server, bese udala amatafula amabili kuyo usebenzisa lo mbuzo olandelayo:
Ukudala amatafula
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
Manje ake sigcwalise ithebula le-Ref ngokusebenzisa umbhalo olandelayo:
Ukugcwalisa ithebula leRef
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
Masigcwalise ngokufanayo ithebula Lekhasimende sisebenzisa umbhalo olandelayo:
Ukugcwalisa ithebula Lekhasimende
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
Ngakho, sithole amathebula amabili, elilodwa linemigqa yedatha engaphezu kwesigidi, kanti elinye linemigqa yedatha engaphezu kwezigidi ezingu-1.
Manje ku-Visual Studio udinga ukudala iphrojekthi yokuhlola ye-Visual C# Console App (.NET Framework):
Okulandelayo, udinga ukwengeza umtapo wolwazi ukuze Uhlaka Lwebhizinisi luhlanganyele nesizindalwazi.
Ukuze uyengeze, chofoza kwesokudla kuphrojekthi bese ukhetha Phatha amaphakheji we-NuGet kumenyu yokuqukethwe:
Bese, efasiteleni lokuphatha iphakheji le-NuGet elivelayo, faka igama elithi βEntity Frameworkβ efasiteleni lokusesha bese ukhetha iphakethe le-Entity Framework bese ulifaka:
Okulandelayo, kufayela le-App.config, ngemva kokuvala isici se-configSections, udinga ukwengeza ibhulokhi elandelayo:
<connectionStrings>
<add name="DBConnection" connectionString="data source=ΠΠΠ―_ΠΠΠΠΠΠΠΠ―Π Π_MSSQL;Initial Catalog=TEST;Integrated Security=True;" providerName="System.Data.SqlClient" />
</connectionStrings>
Ku-ConnectionString udinga ukufaka intambo yokuxhuma.
Manje ake sakhe izixhumanisi ezi-3 kumafayela ahlukene:
- Ukusebenzisa isixhumi esibonakalayo se-IBaseEntityID
namespace TestLINQ { public interface IBaseEntityID { int ID { get; set; } } } - Ukuqaliswa kokusetshenziswa kubonwa kwe-IBaseEntityName
namespace TestLINQ { public interface IBaseEntityName { string Name { get; set; } } } - Ukuqaliswa kokusetshenziswa kubonwa kwe-IBaseNameInsertUTCDate
namespace TestLINQ { public interface IBaseNameInsertUTCDate { DateTime InsertUTCDate { get; set; } } }
Futhi efayeleni elihlukile sizodala i-BaseEntity yesigaba sesisekelo sezinhlangano zethu ezimbili, ezizofaka izinkambu ezivamile:
Ukuqaliswa kwe-base class BaseEntity
namespace TestLINQ
{
public class BaseEntity : IBaseEntityID, IBaseEntityName, IBaseNameInsertUTCDate
{
public int ID { get; set; }
public string Name { get; set; }
public DateTime InsertUTCDate { get; set; }
}
}
Okulandelayo, sizodala izinhlangano zethu ezimbili ngamafayela ahlukene:
- Ukuqaliswa kwesigaba seRef
using System.ComponentModel.DataAnnotations.Schema; namespace TestLINQ { [Table("Ref")] public class Ref : BaseEntity { public int ID2 { get; set; } } } - Ukuqaliswa kwekilasi leKhasimende
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; } } }
Manje ake sakhe umongo we-UserContext efayeleni elihlukile:
Ukuqaliswa kwekilasi le-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; }
}
}
Sithole isixazululo esenziwe ngomumo sokwenza izivivinyo zokuthuthukisa nge-LINQ kuya ku-SQL nge-EF ye-MS SQL Server:
Manje faka ikhodi elandelayo efayeleni le-Program.cs:
Ifayela le-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();
}
}
}
}
Okulandelayo, ake sethule iphrojekthi yethu.
Ekupheleni komsebenzi, okulandelayo kuzovezwa kukhonsoli:
Kwenziwe Umbuzo we-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])
Okusho ukuthi, ngokujwayelekile, umbuzo we-LINQ ukhiqize umbuzo we-SQL ku-MS SQL Server DBMS kahle kakhulu.
Manje ake siguqule isimo KANYE sibe NOMA embuzweni we-LINQ:
Umbuzo we-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 };
Futhi masiqalise uhlelo lwethu lokusebenza futhi.
Ukwenza kuzophahlazeka ngephutha ngenxa yesikhathi sokwenza umyalo esidlula imizuzwana engama-30:
Uma ubheka umbuzo owenziwe yi-LINQ:
, khona-ke ungaqiniseka ukuthi ukukhetha kwenzeka ngomkhiqizo weCartesian wamasethi amabili (amatafula):
Kwenziwe Umbuzo we-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]
Masibhale kabusha umbuzo we-LINQ kanje:
Kulungiselelwe umbuzo we-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 });
Bese sithola umbuzo olandelayo we-SQL:
Umbuzo we-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]
Maye, emibuzweni ye-LINQ kungaba nesimo sokujoyina esisodwa kuphela, ngakho-ke lapha kungenzeka ukwenza umbuzo olinganayo usebenzisa imibuzo emibili kusimo ngasinye bese uyihlanganisa nge-Union ukuze ukhiphe izimpinda phakathi kwemigqa.
Yebo, imibuzo ngokuvamile ngeke ilingane, kucatshangelwa ukuthi imigqa eyimpinda ephelele ingase ibuyiswe. Kodwa-ke, empilweni yangempela, imigqa eyimpinda ephelele ayidingeki futhi abantu bazama ukuyisusa.
Manje ake siqhathanise izinhlelo zokusebenza zale mibuzo emibili:
- kokuthi CROSS JOIN isikhathi sokwenza esimaphakathi amasekhondi angu-195:
- ku-INNER JOIN-UNION isikhathi sokwenza esimaphakathi singaphansi kwamasekhondi angu-24:
.
Futhi kule nqolobane, kufolda Yezinhlelo, kunezinhlelo zokwenza imibuzo ngemibandela NOMA.
Source: www.habr.com