- 恢复 IBaseRepository SaveMany 方法；

FreeSql.DbContext/DbSet/DbSetSync.cs

@@ -843,5 +843,73 @@ namespace FreeSql
             }
         }
         #endregion
+
+        /// <summary>
+        /// 保存实体的指定 ManyToMany/OneToMany 导航属性（完整对比）<para></para>
+        /// 场景：在关闭级联保存功能之后，手工使用本方法<para></para>
+        /// 例子：保存商品的 OneToMany 集合属性，SaveMany(goods, "Skus")<para></para>
+        /// 当 goods.Skus 为空(非null)时，会删除表中已存在的所有数据<para></para>
+        /// 当 goods.Skus 不为空(非null)时，添加/更新后，删除表中不存在 Skus 集合属性的所有记录
+        /// </summary>
+        /// <param name="item">实体对象</param>
+        /// <param name="propertyName">属性名</param>
+        public void SaveMany(TEntity item, string propertyName)
+        {
+            if (item == null) return;
+            if (string.IsNullOrEmpty(propertyName)) return;
+            if (_table.Properties.TryGetValue(propertyName, out var prop) == false) throw new KeyNotFoundException(DbContextStrings.NotFound_Property(_table.Type.FullName, propertyName));
+            if (_table.ColumnsByCsIgnore.ContainsKey(propertyName)) throw new ArgumentException(DbContextStrings.TypeHasSetProperty_IgnoreAttribute(_table.Type.FullName, propertyName));
+
+            var tref = _table.GetTableRef(propertyName, true, false);
+            if (tref == null) return;
+            switch (tref.RefType)
+            {
+                case TableRefType.OneToOne:
+                case TableRefType.ManyToOne:
+                case TableRefType.PgArrayToMany:
+                    throw new ArgumentException(DbContextStrings.PropertyOfType_IsNot_OneToManyOrManyToMany(_table.Type.FullName, propertyName));
+            }
+
+            DbContextFlushCommand();
+            var oldEnable = _db.Options.EnableCascadeSave;
+            _db.Options.EnableCascadeSave = false;
+            try
+            {
+                AddOrUpdateNavigate(item, false, propertyName);
+                if (tref.RefType == TableRefType.OneToMany)
+                {
+                    DbContextFlushCommand();
+                    //删除没有保存的数据，求出主体的条件
+                    var deleteWhereParentParam = Expression.Parameter(typeof(object), "a");
+                    Expression whereParentExp = null;
+                    for (var colidx = 0; colidx < tref.Columns.Count; colidx++)
+                    {
+                        var whereExp = Expression.Equal(
+                            Expression.MakeMemberAccess(Expression.Convert(deleteWhereParentParam, tref.RefEntityType), tref.RefColumns[colidx].Table.Properties[tref.RefColumns[colidx].CsName]),
+                            Expression.Constant(
+                                FreeSql.Internal.Utils.GetDataReaderValue(
+                                    tref.Columns[colidx].CsType,
+                                    _db.OrmOriginal.GetEntityValueWithPropertyName(_table.Type, item, tref.Columns[colidx].CsName)), tref.RefColumns[colidx].CsType)
+                            );
+                        if (whereParentExp == null) whereParentExp = whereExp;
+                        else whereParentExp = Expression.AndAlso(whereParentExp, whereExp);
+                    }
+                    var propValEach = GetItemValue(item, prop) as IEnumerable;
+                    var subDelete = _db.OrmOriginal.Delete<object>().AsType(tref.RefEntityType)
+                        .WithTransaction(_uow?.GetOrBeginTransaction())
+                        .Where(Expression.Lambda<Func<object, bool>>(whereParentExp, deleteWhereParentParam));
+                    foreach (var propValItem in propValEach)
+                    {
+                        subDelete.WhereDynamic(propValEach, true);
+                        break;
+                    }
+                    subDelete.ExecuteAffrows();
+                }
+            }
+            finally
+            {
+                _db.Options.EnableCascadeSave = oldEnable;
+            }
+        }
     }
 }