前言：

最近由于工作需要，需要选用一种ORM框架，也因此对EF Core、FreeSql、SqlSuger作简单对比。个人认为各有有优势，存在即合理，不然早就被淘汰了是吧，所以如何选择因人而议、因项目而议,下面开始正题。

环境说明：项目环境ASP .Net Core Web Api，目标框架：.Net 5，依赖包：


一：准备数据实体类

1 /// 
2 ///班级3 /// 
4 public classClassGrade5 {6 [FreeSql.DataAnnotations.Column(IsIdentity = true, IsPrimary = true)]//FreeSql
7 [SugarColumn(IsPrimaryKey = true, IsIdentity = true)]//Sugar
8 [Key,DatabaseGenerated(DatabaseGeneratedOption.Identity)] //Ef设置自增(int类型默认自增)
9 public int Id { get; set; }10 public string Name { get; set; }11 [SugarColumn(IsIgnore = true)]12 public virtual ICollection Students { get; set; }13 [SugarColumn(IsIgnore = true)]14 public virtual ICollection Classs { get; set; }//15 }16 /// 
17 ///课程18 /// 
19 public classCourse20 {21 [FreeSql.DataAnnotations.Column(IsIdentity = true, IsPrimary = true)]//FreeSql
22 [SugarColumn(IsPrimaryKey = true, IsIdentity = true)]//Sugar
23 [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] //Ef设置自增(int类型默认自增)
24 public int Id { get; set; }25 public string Name { get; set; }26 public virtual string Teacher { get; set; }27 [SugarColumn(IsIgnore = true)]28 public virtual ICollection ClassStudents { get; set; }//班级学生
29 [SugarColumn(IsIgnore = true)]30 public virtual ICollection Students { get; set; }//选修学生
31 }32 /// 
33 ///学生34 /// 
35 public classStudent36 {37 [FreeSql.DataAnnotations.Column(IsIdentity = true, IsPrimary = true)]//FreeSql
38 [SugarColumn(IsPrimaryKey = true, IsIdentity = true)]//Sugar
39 [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] //Ef设置自增(int类型默认自增)
40 public int Id { get; set; }41 public string Name { get; set; }42 public int Age { get; set; }43 public int Sex { get; set; }44 public int ClassId { get; set; }45 [SugarColumn(IsIgnore = true)]46 public virtual ClassGrade Class { get; set; }47 [SugarColumn(IsIgnore = true)]48 public virtual ICollection Courses { get; set; }//辅修课、自选课
49 }50 {51 /// 
52 ///中间表(班级-课程)53 /// 
54 public classMiddleClassCourse55 {56 [FreeSql.DataAnnotations.Column(IsIdentity = true, IsPrimary = true)]//FreeSql
57 [SugarColumn(IsPrimaryKey = true, IsIdentity = true)]//Sugar
58 [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] //Ef设置自增(int类型默认自增)
59 public int Id { get; set; }60 public int ClassId { get; set; }61 [SugarColumn(IsIgnore = true)]62 public virtual ClassGrade Class { get; set; }63 public int CourseId { get; set; }64 [SugarColumn(IsIgnore = true)]65 public virtual Course Course { get; set; }66 }67 /// 
68 ///中间表(学生-课程)69 /// 
70 public classMiddleStudentCourse71 {72 [FreeSql.DataAnnotations.Column(IsIdentity = true, IsPrimary = true)]//FreeSql
73 [SugarColumn(IsPrimaryKey = true, IsIdentity = true)]//Sugar
74 [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] //Ef设置自增(int类型默认自增)
75 public int Id { get; set; }76 public int CourseId { get; set; }77 [SugarColumn(IsIgnore = true)]78 public virtual Course Course { get; set; }79 public int StudentId { get; set; }80 [SugarColumn(IsIgnore = true)]81 public virtual Student Student { get; set; }82 }
二:Code First
1. EF的流程相对比较复杂，但是功能也更强大，具体流程我在这里就不仔细叙述了，下面是EF的DbContext类
public classEfDbContext : DbContext
{/// 
///指定静态ILoggerFactory/// 
public static readonly ILoggerFactory MyLoggerFactory = LoggerFactory.Create(builder =>{ builder.AddConsole(); });publicEfDbContext() { }public EfDbContext(DbContextOptionsoptions)
:base(options)
{
}private string Conn = null;public DbContext ToWriteOrRead(stringconn)
{
Conn=conn;return this;
}protected override voidOnConfiguring(DbContextOptionsBuilder optionsBuilder)
{if (!optionsBuilder.IsConfigured)
{
optionsBuilder.UseLoggerFactory(MyLoggerFactory)//.UseLazyLoadingProxies()
.UseSqlServer(Conn);
}
optionsBuilder.UseLoggerFactory(MyLoggerFactory);
}protected override voidOnModelCreating(ModelBuilder modelBuilder)
{#region MyRegion{//指定主键//modelBuilder.Entity().HasKey(a => a.Id);
/设置数据库架构
//modelBuilder.HasDefaultSchema("xl");
/表名、属性名映射
//modelBuilder.Entity().ToTable("UserInfos", "Zhaoxi").Property(p => p.UserAge).HasColumnName("Age");
设置联合主键
//modelBuilder.Entity().HasKey(p => new { p.SysUserId, p.SysRoleId });
初始化数据
//modelBuilder.Entity().HasData(new List()//{//});
///表拆分:在数据库中是一整张表，在代码层面是多个实体与其对应；
//modelBuilder.Entity(dob =>//{//dob.ToTable("SysLogInfo");//dob.Property(o => o.LogType).HasColumnName("LogType");//配置两个实体的相同属性映射到表的同一列//dob.HasOne(o => o.SysLogDetail).WithOne().HasForeignKey(o => o.Id); ;//配置两个实体的相同属性映射到表的同一列//});//modelBuilder.Entity(dob =>//{//dob.ToTable("SysLogInfo");//dob.Property(o => o.LogType).HasColumnName("LogType");//配置两个实体的相同属性映射到表的同一列//});
}//设置一对多的关系
modelBuilder.Entity().HasOne(c => c.Class).WithMany(s => s.Students).HasForeignKey(b =>b.ClassId);多对多关系
modelBuilder.Entity(eb =>{
eb.HasOne(p=> p.Course).WithMany(u => u.Students).HasForeignKey(u =>u.CourseId);
eb.HasOne(p=> p.Student).WithMany(r => r.Courses).HasForeignKey(s =>s.StudentId);
});
modelBuilder.Entity(eb =>{
eb.HasOne(p=> p.Course).WithMany(u => u.ClassStudents).HasForeignKey(u =>u.CourseId);
eb.HasOne(p=> p.Class).WithMany(r => r.Classs).HasForeignKey(s =>s.ClassId);
});#endregion}public DbSet Classs { get; set; }public DbSet Students { get; set; }public DbSet Courses { get; set; }
}
2.FreeSql的流程相对EF就简单许多了，不需要执行“Add-Migration”、“Update-Database”命令，运行时检查没有表自动创建，下面是FreeSql的DbContext类，与EF很相似。
public classFreeSqlContext: DbContext
{public DbSet Students { get; set; }public DbSet Courses { get; set; }public DbSet ClassGrades { get; set; }public DbSet MiddleClassCourses { get; set; }public DbSet MiddleStudentCourses { get; set; }//每个 DbContext 只触发一次
protected override voidOnModelCreating(ICodeFirst codefirst)
{
codefirst.Entity(eb =>{
eb.HasOne(a=> a.Class).HasForeignKey(b => b.ClassId).WithMany(c =>c.Students);
});
codefirst.Entity(eb =>{
eb.HasOne(a=> a.Student).WithMany(t => t.Courses).HasForeignKey(b =>b.StudentId);
eb.HasOne(a=> a.Course).WithMany(t => t.Students).HasForeignKey(a =>a.CourseId);
});
codefirst.Entity(eb =>{
eb.HasOne(a=> a.Course).WithMany(t => t.ClassStudents).HasForeignKey(a =>a.CourseId);
eb.HasOne(a=> a.Class).WithMany(t => t.Students).HasForeignKey(a =>a.ClassId);
});
}
}
3.SqlSuger就更简单了，不需要配置DbContext，配置如下泛型类就可以了，T为实体类
public class SqlSugerContext: SimpleClient where T : class, new()
{public SqlSugerContext(SqlSugarClient context) : base(context)
{
context.CodeFirst.SetStringDefaultLength(200).InitTables(typeof(T));//这样一个表就能成功创建了
}
}public class ClassGradeService: SqlSugerContext{public ClassGradeService(SqlSugarClient context):base(context)
{
}
}public class CourseService: SqlSugerContext{public CourseService(SqlSugarClient context) : base(context)
{
}
}public class StudentService: SqlSugerContext{public StudentService(SqlSugarClient context) : base(context)
{
}
}public class MiddleClassCourseCervice : SqlSugerContext{public MiddleClassCourseCervice(SqlSugarClient context) : base(context)
{
}
}public class MiddleStudentCourseService : SqlSugerContext{public MiddleStudentCourseService(SqlSugarClient context) : base(context)
{
}
}
三：配置声明
1.连接字符串(都实现了读写分离，由于只是测试，数据库主从都是同一个库，实际上不能这样写，不然没有读写分离的意义)：
"EfConnectionStrings": {"WriteConnection": "Server=localhost;Database=DbEfCore;Trusted_Connection=True;","ReadConnectionList": ["Server=localhost;Database=DbEfCore;Trusted_Connection=True;"]
},"FreeSqlConnectionStrings": "Server=localhost;Database=DbFreeSql;Trusted_Connection=True;","SqlSugerConnectionStrings": "Server=localhost;Database=DbSqlSuger;Trusted_Connection=True;"
2.EF实现读写分离需要自行封装，另外两个只需要配置好连接字符就好了，下面是EF数据库读写分离的实现：
public enumWriteAndReadEnum
{
Write,//主库操作
Read //从库操作
}
public interface IDbContextFactory
{
public EfDbContext ConnWriteOrRead(WriteAndReadEnum writeAndRead);
}
public class DBConnectionOption
{
public string WriteConnection { get; set; }
public List ReadConnectionList { get; set; }
}
public class DbContextFactory : IDbContextFactory
{
private readonly EfDbContext _Context = new EfDbContext();
private static int _iSeed = 0;
private readonly DBConnectionOption _readAndWrite = null;
public DbContextFactory(IOptionsMonitor options)
{
_readAndWrite = options.CurrentValue;
}
public EfDbContext ConnWriteOrRead(WriteAndReadEnum writeAndRead)
{
//判断枚举，不同的枚举可以创建不同的Context 或者更换Context链接；
switch (writeAndRead)
{
case WriteAndReadEnum.Write:
ToWrite();
break; //选择链接//更换_Context链接 //选择链接
case WriteAndReadEnum.Read:
ToRead();
break; //选择链接//更换_Context链接
default:
break;
}
return _Context;
}
/// 
/// 更换成主库连接
/// 
/// 
private void ToWrite()
{
string conn = _readAndWrite.WriteConnection;
_Context.ToWriteOrRead(conn);
}
/// 
/// 更换成主库连接
///
/// ///策略---数据库查询的负载均衡
/// 
/// 
private void ToRead()
{
var conn = this._readAndWrite.ReadConnectionList[_iSeed++ % this._readAndWrite.ReadConnectionList.Count];//轮询;
_Context.ToWriteOrRead(conn);
}
}
3.在Startup.ConfigureServices方法中注入：
#region FreeSql//DbFreeSql
var freestr = Configuration.GetSection("FreeSqlConnectionStrings").Value;
IFreeSql fsql= newFreeSql.FreeSqlBuilder()
.UseConnectionString(FreeSql.DataType.SqlServer, freestr)
.UseSlave(freestr)//使用从数据库，支持多个
.UseAutoSyncStructure(true) //自动同步实体结构到数据库
.Build(); //请务必定义成 Singleton 单例模式
services.AddSingleton(fsql);
services.AddFreeDbContext(options =>options.UseFreeSql(fsql));#endregion
#region SqlSuger//DbSqlSuger
var sugerstr = Configuration.GetSection("SqlSugerConnectionStrings").Value;
services.AddScoped(options=> new SqlSugarClient(newConnectionConfig()
{
ConnectionString= sugerstr,//连接符字串
DbType =DbType.SqlServer,
IsAutoCloseConnection= true,
InitKeyType= InitKeyType.Attribute,//从特性读取主键自增信息
SlaveConnectionConfigs = new List() {//使用从数据库，支持多个
new SlaveConnectionConfig() { HitRate=10, ConnectionString=sugerstr }
}
}));
services.AddScoped();
services.AddScoped();
services.AddScoped();
services.AddScoped();
services.AddScoped();#endregion
#region EfCore//DbEfCoreservices.AddDbContext(options => options.UseSqlServer("name=EfConnectionStrings:WriteConnection"));
services.Configure(Configuration.GetSection("EfConnectionStrings"));//注入多个链接
services.AddTransient();#endregion
四：计时中间件
1.添加一个中间件，用于统计请求Api开始进入管道到结束管道全程耗时
1 public classCalculateExecutionTime2 {3 private readonly RequestDelegate _next;//下一个中间件
4 private readonlyILogger _logger;5 Stopwatch stopwatch;6 publicCalculateExecutionTime(RequestDelegate next, ILoggerFactory loggerFactory)7 {8 if (loggerFactory == null)9 {10 throw newArgumentNullException(nameof(loggerFactory));11 }12 this._next = next ?? throw newArgumentNullException(nameof(next));13 _logger = loggerFactory.CreateLogger();14 }15
16 public asyncTask Invoke(HttpContext context)17 {18 stopwatch = newStopwatch();19 _logger.LogInformation($@"====接口{context.Request.Path}开始计时====");20 stopwatch.Start();//启动计时器
21 await_next.Invoke(context);22 stopwatch.Stop();//停止秒表。
23 _logger.LogInformation($@"====接口{context.Request.Path}耗时:{stopwatch.ElapsedMilliseconds}ms====");24 }25 }26
27 public static IApplicationBuilder UseCalculateExecutionTime(thisIApplicationBuilder app)28 {29 if (app == null)30 {31 throw newArgumentNullException(nameof(app));32 }33 return app.UseMiddleware();34 }
2.使用中间件，Configure中加入如下代码
1 app.UseCalculateExecutionTime();//Api计时

五：总结

到此基本框架就搭建好了，下一篇将分别实现相同功能的三套API进行具体比较。

就目前来说，EF Core 最复杂学习成本高，同时Code First功能也是最强的，SqlSuger最简单容易上手，但是没有严格意义上的Code First，只是能够创建表而已。