EntityFramework性能之預生成視圖

前面提到過這個網址:性能註意事項（實體框架） https://msdn.microsoft.com/zh-cn/library/cc853327.aspx註意版本: .NET Framework (current version) (還有一個其他版本, .NET Framework 4). 此文提到 ...

前面提到過這個網址:性能註意事項（實體框架） https://msdn.microsoft.com/zh-cn/library/cc853327.aspx
註意版本: .NET Framework (current version) (還有一個其他版本, .NET Framework 4).

此文提到查詢執行的各個階段[格式:操作(相對成本)]:
載入元數據(中等),打開資料庫連接(中等),生成視圖(高),準備查詢(中等),執行查詢(低),載入和驗證類型(低),跟蹤(低),是對象具體化(中等)

還是截個圖吧.

其中,我特別在意'生成視圖'這個階段,高成本(其它階段要麼頻率低要麼成本低).
生成視圖,註釋如下:在實體框架可以針對概念模型執行查詢或將更改保存到數據源之前，它必鬚生成一組本地查詢視圖才能訪問資料庫。由於生成這些視圖會產生很高的成本，因此，您可以在設計時預生成視圖並將它們添加到項目。有關詳細信息，請參閱How to: Pre-Generate Views to Improve Query Performance。

於是,我就去看How to: Pre-Generate Views to Improve Query Performance(以下簡稱H文)。(如何：預生成視圖以提高查詢性能)

動手,建立解決方案名EFTest,控制台名EFIce.
簡要說下H文的步驟(跟H文有差異):
a.打開PhoneBookModel.edmx,在模型瀏覽器里,找到PhoneBookModel,右鍵,屬性,有一項屬性名為'元數據項目處理',預設值是'嵌入輸出程式集中',更改為'複製到輸出目錄';
b.生成PhoneBookModel.ssdl,PhoneBookModel.csdl,PhoneBookModel.msl,PhoneBookModel.Views.cs四個文件並加入到項目里,其中.ssdl,.csdl,.msl三個文件的屬性生成操作設置為'嵌入的資源',而PhoneBookModel.Views.cs文件會直接編譯到.dll里.
此處生成文件的方法:命令提示符執行
C:\Users\Administrator>EdmGen /mode:FullGeneration /connectionstring:"server=.;user id=sa;password=******;persist security info=True;database=PhoneBook" /provider:"System.Data.SqlClient" /outssdl:PhoneBookModel.ssdl /outcsdl:PhoneBookModel.csdl /outmsl:PhoneBookModel.msl /outobjectlayer:PhoneBookObject.cs /outviews:PhoneBook.Views.cs /namespace:"EFIce" /entitycontainer:"PhoneBookEntitiesContainer

產生的文件的位置C:\Users\Administrator目錄下.

PhoneBookModel.edmx的圖解:

文件結果:

//------------------------------------------------------------------------------
// <auto-generated>
//     此代碼由工具生成。
//     運行時版本:4.0.30319.36282
//
//     對此文件的更改可能會導致不正確的行為，並且如果
//     重新生成代碼，這些更改將會丟失。
// </auto-generated>
//------------------------------------------------------------------------------

[assembly: System.Data.Mapping.EntityViewGenerationAttribute(typeof(Edm_EntityMappingGeneratedViews.ViewsForBaseEntitySets9E94E67D0053D8FDE07EEEB8F52E0E47D0A29AB22FB0BCB5EB6BE8BC009D5748))]

namespace Edm_EntityMappingGeneratedViews
{
    
    
    /// <Summary>
    /// 此類型包含在設計時生成的 EntitySets 和 AssociationSets 的視圖。
    /// </Summary>
    public sealed class ViewsForBaseEntitySets9E94E67D0053D8FDE07EEEB8F52E0E47D0A29AB22FB0BCB5EB6BE8BC009D5748 : System.Data.Mapping.EntityViewContainer
    {
        
        /// <Summary>
        /// 構造函數存儲各區的視圖，以及根據元數據和映射結束和視圖生成的哈希值。
        /// </Summary>
        public ViewsForBaseEntitySets9E94E67D0053D8FDE07EEEB8F52E0E47D0A29AB22FB0BCB5EB6BE8BC009D5748()
        {
            this.EdmEntityContainerName = "PhoneBookEntitiesContainer";
            this.StoreEntityContainerName = "EFIceStoreContainer";
            this.HashOverMappingClosure = "4c6b0bf3e3884e8b4a6c4c7c60d99b787ec990e9b24297519ab203951cadc07d";
            this.HashOverAllExtentViews = "d048405239ad31569ab8a2a9f67381c39d4130d40b625903b35e1e8d2d1266f5";
            this.ViewCount = 8;
        }
        
        /// <Summary>
        /// 此方法返回給定索引的視圖。
        /// </Summary>
        protected override System.Collections.Generic.KeyValuePair<string, string> GetViewAt(int index)
        {
            if ((index == 0))
            {
                return GetView0();
            }
            if ((index == 1))
            {
                return GetView1();
            }
            if ((index == 2))
            {
                return GetView2();
            }
            if ((index == 3))
            {
                return GetView3();
            }
            if ((index == 4))
            {
                return GetView4();
            }
            if ((index == 5))
            {
                return GetView5();
            }
            if ((index == 6))
            {
                return GetView6();
            }
            if ((index == 7))
            {
                return GetView7();
            }
            throw new System.IndexOutOfRangeException();
        }
        
        /// <Summary>
        /// 返回 EFIceStoreContainer.AccountInfo 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView0()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("EFIceStoreContainer.AccountInfo", @"
    SELECT VALUE -- Constructing AccountInfo
        [EFIce.Store.AccountInfo](T1.AccountInfo_ID, T1.AccountInfo_Account, T1.AccountInfo_AccountName, T1.AccountInfo_Pwd)
    FROM (
        SELECT 
            T.ID AS AccountInfo_ID, 
            T.Account AS AccountInfo_Account, 
            T.AccountName AS AccountInfo_AccountName, 
            T.Pwd AS AccountInfo_Pwd, 
            True AS _from0
        FROM PhoneBookEntitiesContainer.AccountInfo AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 PhoneBookEntitiesContainer.AccountInfo 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView1()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("PhoneBookEntitiesContainer.AccountInfo", @"
    SELECT VALUE -- Constructing AccountInfo
        [EFIce.AccountInfo](T1.AccountInfo_ID, T1.AccountInfo_Account, T1.AccountInfo_AccountName, T1.AccountInfo_Pwd)
    FROM (
        SELECT 
            T.ID AS AccountInfo_ID, 
            T.Account AS AccountInfo_Account, 
            T.AccountName AS AccountInfo_AccountName, 
            T.Pwd AS AccountInfo_Pwd, 
            True AS _from0
        FROM EFIceStoreContainer.AccountInfo AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 EFIceStoreContainer.ContactInfo 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView2()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("EFIceStoreContainer.ContactInfo", @"
    SELECT VALUE -- Constructing ContactInfo
        [EFIce.Store.ContactInfo](T1.ContactInfo_ID, T1.ContactInfo_ContactId, T1.ContactInfo_IsDelete, T1.ContactInfo_Account, T1.ContactInfo_ContactName, T1.ContactInfo_CommonMobile, T1.ContactInfo_HeadPortrait, T1.ContactInfo_AttFile, T1.ContactInfo_GroupId)
    FROM (
        SELECT 
            T.ID AS ContactInfo_ID, 
            T.ContactId AS ContactInfo_ContactId, 
            T.IsDelete AS ContactInfo_IsDelete, 
            T.Account AS ContactInfo_Account, 
            T.ContactName AS ContactInfo_ContactName, 
            T.CommonMobile AS ContactInfo_CommonMobile, 
            T.HeadPortrait AS ContactInfo_HeadPortrait, 
            T.AttFile AS ContactInfo_AttFile, 
            T.GroupId AS ContactInfo_GroupId, 
            True AS _from0
        FROM PhoneBookEntitiesContainer.ContactInfo AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 EFIceStoreContainer.GroupInfo 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView3()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("EFIceStoreContainer.GroupInfo", @"
    SELECT VALUE -- Constructing GroupInfo
        [EFIce.Store.GroupInfo](T1.GroupInfo_GroupId, T1.GroupInfo_GroupName)
    FROM (
        SELECT 
            T.GroupId AS GroupInfo_GroupId, 
            T.GroupName AS GroupInfo_GroupName, 
            True AS _from0
        FROM PhoneBookEntitiesContainer.GroupInfo AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 PhoneBookEntitiesContainer.ContactInfo 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView4()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("PhoneBookEntitiesContainer.ContactInfo", @"
    SELECT VALUE -- Constructing ContactInfo
        [EFIce.ContactInfo](T1.ContactInfo_ID, T1.ContactInfo_ContactId, T1.ContactInfo_IsDelete, T1.ContactInfo_Account, T1.ContactInfo_ContactName, T1.ContactInfo_CommonMobile, T1.ContactInfo_HeadPortrait, T1.ContactInfo_AttFile, T1.ContactInfo_GroupId)
    FROM (
        SELECT 
            T.ID AS ContactInfo_ID, 
            T.ContactId AS ContactInfo_ContactId, 
            T.IsDelete AS ContactInfo_IsDelete, 
            T.Account AS ContactInfo_Account, 
            T.ContactName AS ContactInfo_ContactName, 
            T.CommonMobile AS ContactInfo_CommonMobile, 
            T.HeadPortrait AS ContactInfo_HeadPortrait, 
            T.AttFile AS ContactInfo_AttFile, 
            T.GroupId AS ContactInfo_GroupId, 
            True AS _from0
        FROM EFIceStoreContainer.ContactInfo AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 PhoneBookEntitiesContainer.GroupInfo 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView5()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("PhoneBookEntitiesContainer.GroupInfo", @"
    SELECT VALUE -- Constructing GroupInfo
        [EFIce.GroupInfo](T1.GroupInfo_GroupId, T1.GroupInfo_GroupName)
    FROM (
        SELECT 
            T.GroupId AS GroupInfo_GroupId, 
            T.GroupName AS GroupInfo_GroupName, 
            True AS _from0
        FROM EFIceStoreContainer.GroupInfo AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 EFIceStoreContainer.ContactInGroup 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView6()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("EFIceStoreContainer.ContactInGroup", @"
    SELECT VALUE -- Constructing ContactInGroup
        [EFIce.Store.ContactInGroup](T1.ContactInGroup_Id, T1.ContactInGroup_Account, T1.ContactInGroup_GroupNumber, T1.ContactInGroup_ContactId, T1.ContactInGroup_IsDelete, T1.ContactInGroup_UpdateTime)
    FROM (
        SELECT 
            T.Id AS ContactInGroup_Id, 
            T.Account AS ContactInGroup_Account, 
            T.GroupNumber AS ContactInGroup_GroupNumber, 
            T.ContactId AS ContactInGroup_ContactId, 
            T.IsDelete AS ContactInGroup_IsDelete, 
            T.UpdateTime AS ContactInGroup_UpdateTime, 
            True AS _from0
        FROM PhoneBookEntitiesContainer.ContactInGroup AS T
    ) AS T1");
        }
        
        /// <Summary>
        /// 返回 PhoneBookEntitiesContainer.ContactInGroup 的視圖
        /// </Summary>
        private System.Collections.Generic.KeyValuePair<string, string> GetView7()
        {
            return new System.Collections.Generic.KeyValuePair<string, string>("PhoneBookEntitiesContainer.ContactInGroup", @"
    SELECT VALUE -- Constructing ContactInGroup
        [EFIce.ContactInGroup](T1.ContactInGroup_Id, T1.ContactInGroup_Account, T1.ContactInGroup_GroupNumber, T1.ContactInGroup_ContactId, T1.ContactInGroup_IsDelete, T1.ContactInGroup_UpdateTime)
    FROM (
        SELECT 
            T.Id AS ContactInGroup_Id, 
            T.Account AS ContactInGroup_Account, 
            T.GroupNumber AS ContactInGroup_GroupNumber, 
            T.ContactId AS ContactInGroup_ContactId, 
            T.IsDelete AS ContactInGroup_IsDelete, 
            T.UpdateTime AS ContactInGroup_UpdateTime, 
            True AS _from0
        FROM EFIceStoreContainer.ContactInGroup AS T
    ) AS T1");
        }
    }
}

PhoneBook.Views.cs

<?xml version="1.0" encoding="utf-8"?>
<Schema Namespace="EFIce" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation" xmlns="http://schemas.microsoft.com/ado/2008/09/edm">
  <EntityContainer Name="PhoneBookEntitiesContainer" annotation:LazyLoadingEnabled="true">
    <EntitySet Name="AccountInfo" EntityType="EFIce.AccountInfo" />
    <EntitySet Name="ContactInfo" EntityType="EFIce.ContactInfo" />
    <EntitySet Name="ContactInGroup" EntityType="EFIce.ContactInGroup" />
    <EntitySet Name="GroupInfo" EntityType="EFIce.GroupInfo" />
    <AssociationSet Name="FK_ContactInfo_GroupInfo" Association="EFIce.FK_ContactInfo_GroupInfo">
      <End Role="GroupInfo" EntitySet="GroupInfo" />
      <End Role="ContactInfo" EntitySet="ContactInfo" />
    </AssociationSet>
  </EntityContainer>
  <EntityType Name="AccountInfo">
    <Key>
      <PropertyRef Name="ID" />
    </Key>
    <Property Name="ID" Type="Int32" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
    <Property Name="Account" Type="String" MaxLength="64" Unicode="true" FixedLength="false" />
    <Property Name="AccountName" Type="String" MaxLength="50" Unicode="true" FixedLength="false" />
    <Property Name="Pwd" Type="String" MaxLength="50" Unicode="true" FixedLength="false" />
  </EntityType>
  <EntityType Name="ContactInfo">
    <Key>
      <PropertyRef Name="ID" />
    </Key>
    <Property Name="ID" Type="Int32" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
    <Property Name="ContactId" Type="String" Nullable="false" MaxLength="128" Unicode="true" FixedLength="false" />
    <Property Name="IsDelete" Type="Int32" Nullable="false" />
    <Property Name="Account" Type="String" Nullable="false" MaxLength="64" Unicode="true" FixedLength="false" />
    <Property Name="ContactName" Type="String" Nullable="false" MaxLength="50" Unicode="true" FixedLength="false" />
    <Property Name="CommonMobile" Type="String" MaxLength="50" Unicode="true" FixedLength="false" />
    <Property Name="HeadPortrait" Type="String" MaxLength="256" Unicode="true" FixedLength="false" />
    <Property Name="AttFile" Type="String" MaxLength="256" Unicode="true" FixedLength="false" />
    <Property Name="GroupId" Type="Int32" />
    <NavigationProperty Name="GroupInfo" Relationship="EFIce.FK_ContactInfo_GroupInfo" FromRole="ContactInfo" ToRole="GroupInfo" />
  </EntityType>
  <EntityType Name="ContactInGroup">
    <Key>
      <PropertyRef Name="Id" />
    </Key>
    <Property Name="Id" Type="String" Nullable="false" MaxLength="128" Unicode="false" FixedLength="false" />
    <Property Name="Account" Type="String" Nullable="false" MaxLength="64" Unicode="true" FixedLength="false" />
    <Property Name="GroupNumber" Type="String" Nullable="false" MaxLength="16" Unicode="true" FixedLength="false" />
    <Property Name="ContactId" Type="String" Nullable="false" MaxLength="128" Unicode="false" FixedLength="false" />
    <Property Name="IsDelete" Type="Int32" />
    <Property Name="UpdateTime" Type="DateTime" />
  </EntityType>
  <EntityType Name="GroupInfo">
    <Key>
      <PropertyRef Name="GroupId" />
    </Key>
    <Property Name="GroupId" Type="Int32" Nullable="false" annotation:StoreGeneratedPattern="Identity" />
    <Property Name="GroupName" Type="String" Nullable="false" MaxLength="300" Unicode="true" FixedLength="false" />
    <NavigationProperty Name="ContactInfo" Relationship="EFIce.FK_ContactInfo_GroupInfo" FromRole="GroupInfo" ToRole="ContactInfo" />
  </EntityType>
  <Association Name="FK_ContactInfo_GroupInfo">
    <End Role="GroupInfo" Type="EFIce.GroupInfo" Multiplicity="0..1" />
    <End Role="ContactInfo" Type="EFIce.ContactInfo" Multiplicity="*" />
    <ReferentialConstraint>
      <Principal Role="GroupInfo">
        <PropertyRef Name="GroupId" />
      </Principal>
      <Dependent Role="ContactInfo">
        <PropertyRef Name="GroupId" />
      </Dependent>
    </ReferentialConstraint>
  </Association>
</Schema>

PhoneBookModel.csdl

<?xml version="1.0" encoding="utf-8"?>
<Mapping Space="C-S" xmlns="http://schemas.microsoft.com/ado/2008/09/mapping/cs">
  <EntityContainerMapping StorageEntityContainer="EFIceStoreContainer" CdmEntityContainer="PhoneBookEntitiesContainer">
    <EntitySetMapping Name="AccountInfo">
      <EntityTypeMapping TypeName="EFIce.AccountInfo">
        <MappingFragment StoreEntitySet="AccountInfo">
          <ScalarProperty Name="ID" ColumnName="ID" />
          <ScalarProperty Name="Account" ColumnName="Account" />
          <ScalarProperty Name="AccountName" ColumnName="AccountName" />
          <ScalarProperty Name="Pwd" ColumnName="Pwd" />
        </MappingFragment>
      </EntityTypeMapping>
    </EntitySetMapping>
    <EntitySetMapping Name="ContactInfo">
      <EntityTypeMapping TypeName="EFIce.ContactInfo">
        <MappingFragment StoreEntitySet="ContactInfo">
          <ScalarProperty Name="ID" ColumnName="ID" />
          <ScalarProperty Name="ContactId" ColumnName="ContactId" />
          <ScalarProperty Name="IsDelete" ColumnName="IsDelete" />
          <ScalarProperty Name="Account" ColumnName="Account" />
          <ScalarProperty Name="ContactName" ColumnName="ContactName" />
          <ScalarProperty Name="CommonMobile" ColumnName="CommonMobile" />
          <ScalarProperty Name="HeadPortrait" ColumnName="HeadPortrait" />
          <ScalarProperty Name="AttFile" ColumnName="AttFile" />
          <ScalarProperty Name="GroupId" ColumnName="GroupId" />
        </MappingFragment>
      </EntityTypeMapping>
    </EntitySetMapping>
    <EntitySetMapping Name="ContactInGroup">
      <EntityTypeMapping TypeName="EFIce.ContactInGroup">
        <MappingFragment StoreEntitySet="ContactInGroup">
          <ScalarProperty Name="Id" ColumnName="Id" />
          <ScalarProperty Name="Account" ColumnName="Account" />
          <ScalarProperty Name="GroupNumber" ColumnName="GroupNumber" />
          <ScalarProperty Name="ContactId" ColumnName="ContactId" />
          <ScalarProperty Name="IsDelete" ColumnName="IsDelete" />
          <ScalarProperty Name="UpdateTime" ColumnName="UpdateTime" />
        </MappingFragment>
      </EntityTypeMapping>
    </EntitySetMapping>
    <EntitySetMapping Name="GroupInfo">
      <EntityTypeMapping TypeName="EFIce.GroupInfo">
        <MappingFragment StoreEntitySet="GroupInfo">
          <ScalarProperty Name="GroupId" ColumnName="GroupId" />
          <ScalarProperty Name="GroupName" ColumnName="GroupName" />
        </MappingFragment>
      </EntityTypeMapping>
    </EntitySetMapping>
  </EntityContainerMapping>
</Mapping>

PhoneBookModel.msl

<?xml version="1.0" encoding="utf-8"?>
<Schema Namespace="EFIce.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2008" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl">
  <EntityContainer Name="EFIceStoreContainer">
    <EntitySet Name="AccountInfo" EntityType="EFIce.Store.AccountInfo" store:Type="Tables" Schema="dbo" />
    <EntitySet Name="ContactInfo" EntityType="EFIce.Store.ContactInfo" store:Type="Tables" Schema="dbo" />
    <EntitySet Name="ContactInGroup" EntityType="EFIce.Store.ContactInGroup" store:Type="Tables" Schema="dbo" />
    <