比较爽的导航查询功能-SqlSugarORM

1、导航查询特点

作用：主要处理主对象里面有子对象这种层级关系查询

1.1 无外键开箱就用

其它ORM导航查询 需要 各种配置或者外键，而SqlSugar则开箱就用，无外键，只需配置特性和主键就能使用

1.2 高性能优 

 查询 性能非常强悍  

 支持大数据分页导航查询

3.3 语法超级爽

注意：多级查询时VS有时候没提示直接写就行了

 var list=db.Queryable<Test>()           .Includes(x => x.Provinces,x=>x.Citys ,x=>x.Street)//多级查询 有时候VS没提示手写            .Includes(x => x.ClassInfo)// 一级查询           .ToList();                                   var list=db.Queryable<Test>()        //多级查询  加排序过滤        .Includes(x =>x.Provinces.Where(z=>z.Id>0).OrderBy(z=>z.Id).ToList(),x=>x.Citys,x=>x.Street)         // 一级查询        .Includes(x =>x.ClassInfo)        .ToList();

　　

2、新导航查询 

适合有主键的常规操作, 请升级到5.0.6.8

2.1 一对一

//实体        public class StudentA        {            [SugarColumn(IsPrimaryKey = true)]            public int StudentId { get; set; }            public string Name { get; set; }            public int SchoolId { get; set; }            [Navigat(NavigatType.OneToOne, nameof(SchoolId))]//一对一            public SchoolA SchoolA { get; set; }          }        public class SchoolA        {            [SugarColumn(IsPrimaryKey = true)]            public int SchoolId { get; set; }            public string SchoolName { get; set; }         }//代码 var list2 = db.Queryable<StudentA>()           .Includes(x => x.SchoolA)           .Where(x => x.SchoolA.SchoolName == "北大")//可以对一级导航进行过滤           .ToList();

2.2 一对多

    public class StudentA    {     [SugarColumn(IsPrimaryKey = true)]     public int StudentId { get; set; }     public string Name { get; set; }     public int SchoolId { get; set; }     [Navigat(NavigatType.OneToMany, nameof(BookA.studenId))]     public List<BookA> Books { get; set; }      }    public class BookA    {       [SugarColumn(IsPrimaryKey = true)]       public int BookId { get; set; }      public string Name { get; set; }      public int studenId { get; set; }    }             //例1: 简单用法    var list = db.Queryable<StudentA>()    .Includes(x => x.Books)    .ToList();         //例2:支持Any和Count 对主表进行过滤    var list = db.Queryable<StudentA>()    .Includes(x => x.Books)     .Where(x=>x.Books.Any(z=>z.BookId==1))    .ToList();         //例3:对子对象进行排序和过滤     var list = db.Queryable<StudentA>()       .Includes(x => x.Books.Where(y=>y.BookId >0).OrderBy(y=>y.BookId ).ToList())        .ToList();

　　

2.3 多对多

   //多对多       public class ABMapping1       {            [SugarColumn(IsPrimaryKey = true )]            public int AId { get; set; }            [SugarColumn(IsPrimaryKey = true)]            public int BId { get; set; }        }        public class A1        {            [SugarColumn(IsPrimaryKey = true  )]            public int Id { get; set; }            public string Name { get; set; }            [Navigat(typeof(ABMapping1),nameof(ABMapping1.AId),nameof(ABMapping1.BId))]            public List<B1> BList { get; set; }        }        public class B1        {            [SugarColumn(IsPrimaryKey = true )]            public int Id { get; set; }            public string Name { get; set; }            [Navigat(typeof(ABMapping1), nameof(ABMapping1.BId), nameof(ABMapping1.AId))]            public List<A1> AList { get; set; }        } //例1:简单用法var list3= db.Queryable<A1>().Includes(x => x.BList).ToList();   //例2:支持子对象排序和过滤var list3= db.Queryable<A1>().Includes(x => x.BList.Where(z=>z.Id>0).ToList()).ToList();   //例3:支持主表过滤  Any和Countvar list3= db.Queryable<A1>().Includes(x => x.BList)                             .Where(x=>x.BList .Any(z=>z.Id ==1)).ToList();

 

2.4 多级查询

配置好实体类，我们可以多级查询

 var list=db.Queryable<Test>()                .Includes(x => x.Provinces,x=>x.Citys ,x=>x.Street)//有时候没提示 直接写                .Includes(x => x.ClassInfo)// 一级查询                .ToList();

　　

2.5 大数据分页导航 

适合一次性查询1000条以上的导航

  var list = new List<Tree1>();     db.Queryable<Tree1>()        .Includes(it => it.Child)        .ForEach(it => list.Add(it), 300); //每次查询300条　

 更多用法：https://www.donet5.com/Home/Doc?typeId=2414

 

3、无配置映射（高性能）

适合没有主键或者复杂的一些操作

 

 3.1 无配置映射实现二层

结构:  Student->SchoolA

var list = db.Queryable<StudentA>().ToList();db.ThenMapper(list, stu =>{  //如果加Where不能带有stu参数，stu参数写到 SetContext  stu.SchoolA=db.Queryable<SchoolA>().SetContext(scl=>scl.SchoolId,()=>stu.SchoolId,stu).FirstOrDefault();});// SetContext不会生成循环操作，高性能  和直接Where性能是不一样的

如果没有SetContext那么这个查询将会循环

3.2  无配置映射无限级

了解原理后我们用ThenMapper想映射哪层就映射哪层

var treeRoot=db.Queryable<Tree>().Where(it => it.Id == 1).ToList();//第一层db.ThenMapper(treeRoot, item =>{    item.Child = db.Queryable<Tree>().SetContext(x => x.ParentId, () => item.Id, item).ToList();});//第二层db.ThenMapper(treeRoot.SelectMany(it=>it.Child), it =>{    it.Child = db.Queryable<Tree>().SetContext(x => x.ParentId, () => it.Id, it).ToList();});//第三层db.ThenMapper(treeRoot.SelectMany(it => it.Child).SelectMany(it=>it.Child), it =>{    it.Child = db.Queryable<Tree>().SetContext(x => x.ParentId, () => it.Id, it).ToList();});//这儿只是用树型结构来证明可以实现无限级别导航查询 ,实际开发中树型结构用ToTree实现public class Tree{[SqlSugar.SugarColumn(IsPrimaryKey =true)]public int Id { get; set; }public string Name { get; set; }public int ParentId { get; set; }[SqlSugar.SugarColumn(IsIgnore = true)]public Tree Parent { get; set; }[SqlSugar.SugarColumn(IsIgnore = true)]public List<Tree> Child { get; set; }}// SetContext不会生成循环操作，高性能  和直接Where性能是不一样的

 

4 、未来计划

Json to sql  正在开发中 ，未来将打造一套直接由前端操作数据库的API

 { "Queryable":"order",  Select:[ [{SqlFunc_AggregateMin:["id"]},"id"], [{SqlFunc_GetDate:[]},"Date"] ] }

将支持 权限过滤 ，验证，多表查询，层级导航查询 等　　

 

GitHUB 源码：

https://github.com/donet5/SqlSugar

 

喜欢的可以点个星星、点个关注