In diesem Artikel werden hauptsächlich die Verwendung von Entity Framework zum Betrieb einer SQLite-Datenbank in .Net (C#) und die automatische Erstellung von SQLite-Datenbanken und -Tabellen durch Codefirst sowie einige allgemeine Vorgänge und Konfigurationen vorgestellt.
1. SQLite-bezogene Nuget-Pakete müssen im Projekt installiert werden
Rechtsklick auf den Projektnamen =》Klicken Sie auf „Nuget-Pakete verwalten“ =》Suchen“System.Data.SQLite" =》Klicken Sie auf „System.Data.SQLite(x86/x64)“ , "System.Data.SQLite EF6", "System.Data.SQLite LINQ" Diese drei Pakete werden installiert.
Suchen"SQLite.CodeFirst" =》Zum Installieren klicken
Stellen Sie sicher, dass die folgenden Nuget-Pakete installiert sind:
System.Data.SQLite(x86/x64)System.Data.SQLite EF6System.Data.SQLite LINQSQLite.CodeFirstEntity Framework
2. Code im Projekt
1) Erstellen Sie eine neue ORMContext-Klasse, die DbContext erbt
using SQLite.CodeFirst;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using UtilityWeb.ORM.Models;
namespace UtilityWeb.ORM
{
public class ORMContext : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
var sqliteConnectionInitializer = new SqliteCreateDatabaseIfNotExists<ORMContext>(modelBuilder);
Database.SetInitializer(sqliteConnectionInitializer);
}
public ORMContext() : base("ORMContext") { } //配置使用的连接名
public DbSet<EmployInfo> EmployInfos { get; set; }
public DbSet<DeptInfo> DeptInfos { get; set; }
}
}
2）用到的Model类DeptInfo和EmployInfo
public class EmployInfo
{
public string DeptName { get; set; }
public string EmployName { get; set; }
public string Gender { get; set; }
[Key]
public string UserCode { get; set; }
public int RuleCode { get; set; }
public int OrderCode { get; set; }
}
public class DeptInfo
{
public string SubDept { get; set; }
public string DeptName { get; set; }
public string DeptCode { get; set; }
public string RuleCode { get; set; }
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int DeptId { get; set; }
}Erklärung:[key] ist der Konfigurations-Primärschlüssel, [DatabaseGenerated(DatabaseGeneratedOption.Identity)] ist der automatisch inkrementierende Konfigurations-Primärschlüssel
3) Verwenden Sie den Operationsbeispielcode
public static void AddDeptInfo(DeptInfo m)
{
using (ORMContext db = new ORMContext())
{
var model = db.DeptInfos.Where(w => w.DeptName.Trim() == m.DeptName.Trim() && w.SubDept.Trim() == m.SubDept.Trim()).FirstOrDefault();
if (model == null)
{
db.DeptInfos.Add(m);
db.SaveChanges();
return;
}
model.SubDept = m.SubDept.Trim();
model.DeptName = m.DeptName.Trim();
model.DeptCode = m.DeptCode.Trim();
model.RuleCode = m.RuleCode.Trim();
db.SaveChanges();
}
}
public static void AddUserInfo(EmployInfo u)
{
using (ORMContext db = new ORMContext())
{
var model = db.EmployInfos.Where(w => w.UserCode == u.UserCode).FirstOrDefault();
if (model == null)
{
db.EmployInfos.Add(u);
db.SaveChanges();
return;
}
model.UserCode = u.UserCode;
model.Gender = u.Gender;
model.EmployName = u.EmployName;
model.RuleCode = u.RuleCode;
db.SaveChanges();
}
}3. Im Projekt verwendete Konfigurationsdateien
Wenn seltsame Probleme auftreten, überprüfen Sie sorgfältig entityFramework unter providers und DbProviderFactories in der Konfigurationsdatei und generieren Sie automatisch Änderungen Die Konfigurationsdatei hat manchmal Probleme, und ich bin schon zuvor ausgetrickst worden.
1) Konfigurationsdatei des Konsolenprogramms
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<connectionStrings>
<add name="ORMContext" connectionString="data source=.\utilityweb.db" providerName="System.Data.SQLite.EF6" />
</connectionStrings>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
</startup>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="mssqllocaldb" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SQLite.EF6" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />
<provider invariantName="System.Data.SQLite" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />
</providers>
</entityFramework>
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SQLite.EF6" />
<add name="SQLite Data Provider" invariant="System.Data.SQLite" description=".Net Framework Data Provider for SQLite"
type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite"/>
<add name="SQLite Data Provider (Entity Framework 6)" invariant="System.Data.SQLite.EF6"
description=".Net Framework Data Provider for SQLite (Entity Framework 6)"
type="System.Data.SQLite.EF6.SQLiteProviderFactory, System.Data.SQLite.EF6" />
</DbProviderFactories>
</system.data>
</configuration>2) Konfigurationsdateien, die von Websites verwendet werden
<?xml version="1.0" encoding="utf-8"?>
<!--
有关如何配置 ASP.NET 应用程序的详细信息，请访问
http://go.microsoft.com/fwlink/?LinkId=152368
-->
<configuration>
<configSections>
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<connectionStrings>
<add name="ORMContext" connectionString="data source=D:\dbpath\utilityweb.db" providerName="System.Data.SQLite.EF6" />
</connectionStrings>
<appSettings>
<add key="webpages:Version" value="2.0.0.0" />
<add key="webpages:Enabled" value="false" />
<add key="PreserveLoginUrl" value="true" />
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
<add key="DbConnectString" value="User Id=BFCSJQ;Password=DHHZDHHZ;Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.255.90)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=srvcbzb1)))" />
</appSettings>
<system.web>
<httpRuntime targetFramework="4.5" />
<compilation debug="true" targetFramework="4.5" />
<authentication mode="Forms">
<forms loginUrl="~/Account/Login" timeout="2880" />
</authentication>
<pages>
<namespaces>
<add namespace="System.Web.Helpers" />
<add namespace="System.Web.Mvc" />
<add namespace="System.Web.Mvc.Ajax" />
<add namespace="System.Web.Mvc.Html" />
<add namespace="System.Web.Optimization" />
<add namespace="System.Web.Routing" />
<add namespace="System.Web.WebPages" />
</namespaces>
</pages>
<profile defaultProvider="DefaultProfileProvider">
<providers>
<add name="DefaultProfileProvider" type="System.Web.Providers.DefaultProfileProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" />
</providers>
</profile>
<membership defaultProvider="DefaultMembershipProvider">
<providers>
<add name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" />
</providers>
</membership>
<roleManager defaultProvider="DefaultRoleProvider">
<providers>
<add name="DefaultRoleProvider" type="System.Web.Providers.DefaultRoleProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" />
</providers>
</roleManager>
<!--
If you are deploying to a cloud environment that has multiple web server instances,
you should change session state mode from "InProc" to "Custom". In addition,
change the connection string named "DefaultConnection" to connect to an instance
of SQL Server (including SQL Azure and SQL Compact) instead of to SQL Server Express.
-->
<sessionState mode="InProc" customProvider="DefaultSessionProvider">
<providers>
<add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" />
</providers>
</sessionState>
</system.web>
<system.webServer>
<validation validateIntegratedModeConfiguration="false" />
<handlers>
<remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
<remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
<remove name="ExtensionlessUrlHandler-Integrated-4.0" />
<add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
<add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
<add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
</handlers>
</system.webServer>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" />
<bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="0.0.0.0-1.3.0.0" newVersion="1.3.0.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
<parameters>
<parameter value="v12.0" />
</parameters>
</defaultConnectionFactory>
<providers>
<provider invariantName="System.Data.SQLite.EF6" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />
<provider invariantName="System.Data.SQLite" type="System.Data.SQLite.EF6.SQLiteProviderServices, System.Data.SQLite.EF6" />
</providers>
</entityFramework>
<system.data>
<DbProviderFactories>
<remove invariant="System.Data.SQLite.EF6" />
<add name="SQLite Data Provider" invariant="System.Data.SQLite" description=".Net Framework Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />
<add name="SQLite Data Provider (Entity Framework 6)" invariant="System.Data.SQLite.EF6" description=".Net Framework Data Provider for SQLite (Entity Framework 6)" type="System.Data.SQLite.EF6.SQLiteProviderFactory, System.Data.SQLite.EF6" />
</DbProviderFactories>
</system.data>
</configuration>