FreeSql基础入门

github地址：https://github.com/dotnetcore/FreeSql/wiki

一、了解到FreeSql

     ORM框架是很早之前就在接触了比如CYQ.Data，这段时间在群里面发现有的猿在用一个新的ORM框架,这个也是由于自己刚刚得知有这么个ORM的原因，那就是FreeSql,这是一个功能强大的对象关系映射程序(O/RM)，支持 .NETCore 2.1+ 或 .NETFramework 4.5+,目前更新到了0.9版本，FreeSql 使用模型执行数据访问，模型由实体类表示数据库表或视图，用于查询和保存数据。

二、安装FreeSql

     第1种： 通过NuGet程序包里面搜索FreeSql,可以搜索到FreeSql的安装包和支持的数据库安装包,FreeSql.DbContext是必须要的,然后是数据库连接,此处用的是SqlServer,所以安装了FreeSql.Provider.SqlServer。

     第2种：通过控制台程序命令安装,GitHub提供的是 dotnet add package FreeSql,但是此处安装中会提示找不到包,估计是由于不是原始包的原因,采用了dotnet add   项目名称 package FreeSql  就可以解决,不过还是建议采用第一种方式进行安装.

三、项目配置和使用:此处采用的是dotnet Core API

     1、创建数据库,配置数据

     

     2、添加dotnet core api项目(这里不再详细说明,反正大家都会....)

     3、配置项目,此处只是实例,所以没有用到批量注入,如有需要了解ORM批量注入的猿友可以查看:https://www.cnblogs.com/chj929555796/p/11114684.html    

public static IFreeSql Fsql { get; private set; }
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;

            Fsql = new FreeSql.FreeSqlBuilder()
                .UseConnectionString(FreeSql.DataType.SqlServer, "Data Source=.;Initial Catalog=FQDemo;Integrated Security=False;User ID=sa;Password=123456")
                .UseAutoSyncStructure(true)
                .UseLazyLoading(true)
                .UseNoneCommandParameter(true)
                .Build();
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
            //注入
            services.AddSingleton<IFreeSql>(Fsql);
            services.AddFreeDbContext<StudentContext>(options => options.UseFreeSql(Fsql));

        }

 4、添加Model    

  public class StuClass
    {
        public int ID { get; set; }

        public string ClassName { get; set; }
    }
  //如果数据库表名和实体表名不一致的情况下需要通过Table来指定数据库表名
  [Table(Name = "Student")]  
    public class Student
    {
        //唯一键标识,不然数据库表字段会根据实体重新生成
        [Column(IsIdentity = true)]
        public int StuNo { get; set; }

        public string StuName { get; set; }

        public int StuAge { get; set; }
        public int ClassID { get; set; }

        public StuClass StuClass { get; set; }
    }

   

5、添加一个StudentController控制器，通过构造函数注入

获取数据实例：

public Object GetStudentList()
        {
            ISelect<Student> select = _fsOrm.Select<Student>();
            //多表联合查询(无导航属性联表)
            List<Student> stuJoinDHList = select.LeftJoin<StuClass>((s, c) => s.ClassID == c.ID).ToList();
            //多表联合查询(导航属性联表：s.StuClass.ID为导航属性)
            List<Student> stuJoinList = select.LeftJoin(s => s.ClassID == s.StuClass.ID).ToList();
            //查询所有
            List<Student> stuList = select.ToList();
            //条件查询
            List<Student> stuWhereList = select.Where(s => s.ClassID == 2).ToList();
            //分页查询Page(页码:1开始,每页大小:如每页20条),OrderByDescending倒序,默认为正序
            List<Student> stuPageList = select.Where(s => s.ClassID == 2).Page(1, 20).OrderByDescending(o => o.StuNo).ToList();
            return Newtonsoft.Json.JsonConvert.SerializeObject(stuList);
        }

新增数据实例:

 public Object AddStudent()
        {
            FreeSql.IInsert<Student> addStu = _fsOrm.Insert<Student>();
            //添加一行
            Student student = new Student();
            student.StuName = "王五";
            student.StuAge = 0;
            int count1 = addStu.AppendData(student).ExecuteAffrows();
            //批量添加
            List<Student> students = new List<Student>();
            students.Add(new Student()
            {
                StuName = "雨",
                StuAge = 1
            });
            students.Add(new Student()
            {
                StuName = "雪",
                StuAge = 1
            });
            int count2 = addStu.AppendData(students).ExecuteAffrows();
            return true;
        }

修改数据实例：

 public Object UpdateStudent()

        {
            IUpdate<Student> updateStu = _fsOrm.Update<Student>();
            //更新单列
            int count = updateStu.Set(s => s.StuAge, 0).Where(w => w.StuNo == 5).ExecuteAffrows();
            //更新多列
            Student item = new Student { StuNo = 5, StuAge = 1, StuName = "风" };
            int count1 = updateStu.SetSource(item).ExecuteAffrows();
            //批量跟新
            List<Student> students = new List<Student>();
            students.Add(new Student
            {
                StuNo = 4,
                StuName = "张飞",
                StuAge = 1
            });
            students.Add(new Student
            {
                StuNo = 5,
                StuName = "毕傲婵",
                StuAge = 0
            });
            int count2 = updateStu.SetSource(students).ExecuteAffrows();
            students.Clear();
            //保存实体忽略列
            students.Add(new Student
            {
                StuNo = 4,
                StuName = "张飞1",
                StuAge = 0
            });
            students.Add(new Student
            {
                StuNo = 5,
                StuName = "毕傲婵1",
                StuAge = 1
            });
            int count3 = updateStu.SetSource(students).IgnoreColumns(i => i.StuAge).ExecuteAffrows();
            students.Clear();
            //只更新指定的列
            students.Add(new Student
            {
                StuNo = 4,
                StuName = "张飞",
                StuAge = 0
            });
            students.Add(new Student
            {
                StuNo = 5,
                StuName = "毕傲婵",
                StuAge = 1
            });
            int count4 = updateStu.UpdateColumns(s => s.StuName).ExecuteAffrows();
            return count;
        }

删除数据实例，此处删除数据只用了"事务"删除,包括了Transaction、UnitOfWork两种,其他不通过事务和DBContext(暂未发现有Delete操作,不知道后期造轮子的大佬会不会加一颗零件)请自行发挥。

public Object DeleteStu()
        {
            IDelete<Student> delStu = _fsOrm.Delete<Student>();
            IDelete<StuClass> delStuClass = _fsOrm.Delete<StuClass>(); 
            //同线程事务
            _fsOrm.Transaction(() =>
            {
                int count = delStu.Where(w => w.ClassID == 1).ExecuteAffrows();
                if (count > 0)
                    count = delStuClass.Where(w => w.ID == 1).ExecuteAffrows();
                if (count < 1)
                    throw new Exception("处理失败,事务回滚");
            });
            //CreateUnitOfWork(UnitOfWork + Repository)
            using (IRepositoryUnitOfWork sw = _fsOrm.CreateUnitOfWork())
            {
                var delStu1 = sw.GetRepository<Student>();
                var delStuClass1 = sw.GetRepository<StuClass>();                
                int count = delStu1.Delete(d => d.ClassID == 2);
                count = delStuClass1.Delete(d => d.ID == 5);
                if (count > 0)
                {
                    sw.Commit();
                }
                else
                {
                    sw.Rollback();
                    throw new Exception("处理失败,事务回滚");
                }
            };            
            return true;
        }

以上就是学习FreeSql的入门记录,还有很多实例没有一一列举,如有需要的猿友可到https://github.com/2881099/FreeSql/wiki了解,如有不对的地方,感谢指导！

************转摘：https://www.cnblogs.com/chj929555796/p/11557074.html