Support Mapper Many to Many

Src/Asp.Net/SqlServerTest/UnitTest/UQueryable2.cs

@@ -98,9 +98,9 @@ namespace OrmTest
         
             .ToList();
 
-            //var list8 = Db.Queryable<A>()
+            var list8 = Db.Queryable<A>()
-            //.Mapper<ABMapping>(it=>ManyToMany.Config(it.A,it.AId,it.B,it.BId))
+            .Mapper<A,B,ABMapping>(it => ManyToMany.Config(it.AId,it.BId))
-            //.ToList();
+            .ToList();
 
         }
     }

Src/Asp.Net/SqlSugar/Abstract/QueryableProvider/QueryableProvider.cs

@@ -109,10 +109,91 @@ namespace SqlSugar
             this.MapperAction.Add(mapperAction);
             return this;
         }
-        public ISugarQueryable<T> Mapper<MappingType>(Expression<Func<MappingType, ManyToMany>> expression) 
+        public ISugarQueryable<T> Mapper<AType, BType, MappingType>(Expression<Func<MappingType, ManyToMany>> expression)
         {
+            var args = ((expression as LambdaExpression).Body as MethodCallExpression).Arguments;
+
+            Type aType = typeof(AType);
+            Type bType = typeof(BType);
+            Type bListType = typeof(List<BType>);
+
+            this.Context.InitMappingInfo(aType);
+            this.Context.InitMappingInfo(bType);
+            this.Context.InitMappingInfo(typeof(MappingType));
+
+            //Mapping 
+            var mappingEntity = this.Context.EntityMaintenance.GetEntityInfo(typeof(MappingType));
+            string m_aPropertyName = (args[0] as MemberExpression).Member.Name;
+            string m_bPropertyName= (args[1] as MemberExpression).Member.Name;
+            var m_aDbField = mappingEntity.Columns.First(it => it.PropertyName == m_aPropertyName).DbColumnName;
+            var m_bDbField = mappingEntity.Columns.First(it => it.PropertyName == m_bPropertyName).DbColumnName;
+
+            //A
+            var aEntity = this.Context.EntityMaintenance.GetEntityInfo(aType);
+            var aPropertyName = aEntity.Columns.FirstOrDefault(it => it.IsPrimarykey == true).PropertyName;
+
+            //B
+            var bEntity = this.Context.EntityMaintenance.GetEntityInfo(bType);
+            var bProperty = bEntity.Columns.FirstOrDefault(it => it.IsPrimarykey == true).PropertyName;
+            var bDbFiled = bEntity.Columns.FirstOrDefault(it => it.IsPrimarykey == true).DbColumnName;
+            this.Mapper((it,cache) =>
+            {
+               var list= cache.Get<Dictionary<object, List<BType>>>(oldList=> {
+
+
+                   //query mapping by a
+                   var cons = new List<IConditionalModel>() {
+                     new ConditionalModel(){      
+                                                   ConditionalType=ConditionalType.In,
+                                                   FieldName= m_aDbField,
+                                                   FieldValue=string.Join(",",oldList.Select(z=>UtilMethods.GetPropertyValue(z,aPropertyName)).Distinct())
+                                                  }
+                   };
+                   var mappingList = this.Context.Queryable<MappingType>().Where(cons).ToList();
+                   var bids = mappingList.Select(z => UtilMethods.GetPropertyValue(z, m_bPropertyName)).Distinct().ToList();
+
+                   //queryable b by mapping
+                   cons = new List<IConditionalModel>() {
+                     new ConditionalModel(){
+                                                   ConditionalType=ConditionalType.In,
+                                                   FieldName= bDbFiled,
+                                                   FieldValue=string.Join(",",mappingList.Select(z=>UtilMethods.GetPropertyValue(z,m_bPropertyName)).Distinct())
+                                                  }
+                   };
+                   var bList = this.Context.Queryable<BType>().Where(cons).ToList();
+
+                   //get result
+                   Dictionary<object, List<BType>> result = new Dictionary<object, List<BType>>();
+                   var group = mappingList.GroupBy(z => UtilMethods.GetPropertyValue(z, m_aPropertyName));
+                   foreach (var item in group)
+                   {
+                       var currentBids = item.Select(z => UtilMethods.GetPropertyValue(z, m_bPropertyName)).ToList();
+                       result.Add(item.Key, bList.Where(z => currentBids.Contains(UtilMethods.GetPropertyValue(z, bProperty))).ToList());
+                   }
+                   return result;
+
+               }, expression.ToString());
+               foreach (var item in aEntity.Columns)
+               {
+                    var aid = UtilMethods.GetPropertyValue(it, aPropertyName);
+                    if (list.ContainsKey(aid))
+                    {
+                        if (item.PropertyInfo.PropertyType == bType)
+                        {
+                           var b=UtilMethods.ChangeType<BType>(list[aid].FirstOrDefault());
+                            item.PropertyInfo.SetValue(it, b);
+                        }
+                        else if (item.PropertyInfo.PropertyType == bListType)
+                        {
+                            var bList = UtilMethods.ChangeType<List<BType>>(list[aid]);
+                            item.PropertyInfo.SetValue(it, bList);
+                        }
+                    }
+               }
+            });
             return this;
         }
+
         public virtual ISugarQueryable<T> Mapper(Action<T, MapperCache<T>> mapperAction)
         {
             this.MapperActionWithCache = mapperAction;

Src/Asp.Net/SqlSugar/Entities/ManyToManyConfig.cs

@@ -8,11 +8,7 @@ namespace SqlSugar
 {
     public class ManyToMany
     {
-        public static ManyToMany Config<AClass,AField,BClass,BField>(AClass aClass,AField aField,BClass bClass,BField bField) 
+        public static ManyToMany Config<AField,BField>(AField aField,BField bField) 
-            where AClass:class
-            where AField : struct
-            where BClass:class
-            where BField:struct
         {
             return null;
         }

Src/Asp.Net/SqlSugar/Entities/MapperCache.cs

@@ -34,6 +34,21 @@ namespace SqlSugar
                 return result;
             }
         }
+        public Result Get<Result>(Func<List<T>, Result> action,string cachekey)
+        {
+            GetIndex++;
+            string key = "Get" + typeof(Result) + action.GetHashCode() + action.Method.Name+ cachekey;
+            if (caches.ContainsKey(key))
+            {
+                return (Result)caches[key];
+            }
+            else
+            {
+                var result = action(_list);
+                caches.Add(key, result);
+                return result;
+            }
+        }
         public List<Result> GetListByPrimaryKeys<Result>(Func<T, double?> action) where Result : class, new()
         {
             {

Src/Asp.Net/SqlSugar/Interface/IQueryable.cs

@@ -20,7 +20,7 @@ namespace SqlSugar
         ISugarQueryable<T> With(string withString);
         ISugarQueryable<T> Filter(string FilterName, bool isDisabledGobalFilter = false);
         ISugarQueryable<T> Mapper(Action<T> mapperAction);
-        ISugarQueryable<T> Mapper<MappingType>(Expression<Func<MappingType, ManyToMany>> expression);
+        ISugarQueryable<T> Mapper<AType, BType, MappingType>(Expression<Func<MappingType, ManyToMany>> expression);
         ISugarQueryable<T> Mapper(Action<T, MapperCache<T>> mapperAction);
         ISugarQueryable<T> Mapper<TObject>(Expression<Func<T, TObject>> mapperObject, Expression<Func<T, object>> mainField, Expression<Func<T, object>> childField);
         ISugarQueryable<T> Mapper<TObject>(Expression<Func<T, List<TObject>>> mapperObject, Expression<Func<T, object>> mainField, Expression<Func<T, object>> childField);

Src/Asp.Net/SqlSugar/Utilities/UtilMethods.cs

@@ -244,7 +244,10 @@ namespace SqlSugar
         {
             return Convert.ToInt64(string.Join("", bytes).PadRight(20, '0'));
         }
-
+        public static object GetPropertyValue<T>(T t, string PropertyName)
+        {
+            return t.GetType().GetProperty(PropertyName).GetValue(t, null);
+        }
         internal static string GetMD5(string myString)
         {
             MD5 md5 = new MD5CryptoServiceProvider();