- 增加 ISelectGrouping First 方法；

Examples/base_entity/Program.cs

@@ -569,6 +569,8 @@ namespace base_entity
             #endregion
             fsql.UseJsonMap();
 
+            fsql.Select<User1>().IncludeMany(a => a.Roles);
+
             var displayNameTb = fsql.CodeFirst.GetTableByEntity(typeof(DeviceCodes));
 
             var joinsql1 = fsql.Select<JoinTest01>()
@@ -598,7 +600,7 @@ namespace base_entity
 
             Console.WriteLine(sw111);
 
-            var testsql01 =  fsql.Select<User1>()
+            var testsql01 = fsql.Select<User1>()
                 //.GroupBy(a => new { a.Avatar, a.GroupId })
                 //.Having(g => g.Sum(g.Value.Sort) > 0)
                 .WithTempQuery(a => new
@@ -662,13 +664,13 @@ namespace base_entity
                     }
                 }
             };
-
+            if (fsql.Ado.DataType == DataType.PostgreSQL)
-            Npgsql.NpgsqlConnection.GlobalTypeMapper.UseNetTopologySuite();
+            {
-            var geo = new Point(10, 20);
+                Npgsql.NpgsqlConnection.GlobalTypeMapper.UseNetTopologySuite();
-            fsql.Select<City>()
+                var geo = new Point(10, 20);
-                .Where(a => geo.Distance(a.Center) < 100).ToList();
+                fsql.Select<City>()
-
+                    .Where(a => geo.Distance(a.Center) < 100).ToList();
-
+            }
 
             var items = new List<User1>();
             for (var a = 0; a < 3; a++) items.Add(new User1 { Id = Guid.NewGuid(), Avatar = $"avatar{a}" });
@@ -860,6 +862,15 @@ namespace base_entity
                     list2 = userRepository.Select.Where(b => b.GroupId == a.Id).ToList(b => b.Nickname),
                 });
 
+            var testsublist2 = fsql.Select<UserGroup>()
+                .GroupBy(a => new { a.Id })
+                .First(a => new
+                {
+                    a.Id,
+                    list = userRepository.Select.Where(b => b.GroupId == a.Id).ToList(),
+                    list2 = userRepository.Select.Where(b => b.GroupId == a.Id).ToList(b => b.Nickname),
+                });
+
 
             Dictionary<string, object> dic = new Dictionary<string, object>();
             dic.Add("id", 1);
@@ -1985,7 +1996,7 @@ namespace base_entity
         public virtual string Code { get; set; }
         public virtual string Name { get; set; }
     }
-    [Table(Name = "`FreeSqlTest`.`bdd_1`")]
+    [Table(Name = "`bdd_1`")]
     class GoodsData : BaseDataEntity
     {
         public override Int32 CategoryId { get; set; }

FreeSql/Interface/Curd/ISelect/ISelectGrouping.cs

@@ -16,6 +16,8 @@ namespace FreeSql
         Task<long> CountAsync(CancellationToken cancellationToken = default);
         Task<List<TReturn>> ToListAsync<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select, CancellationToken cancellationToken = default);
         Task<Dictionary<TKey, TElement>> ToDictionaryAsync<TElement>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TElement>> elementSelector, CancellationToken cancellationToken = default);
+        Task<TReturn> FirstAsync<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select, CancellationToken cancellationToken = default);
+
 #endif
 
         /// <summary>
@@ -54,6 +56,13 @@ namespace FreeSql
         /// <returns></returns>
         List<TReturn> ToList<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select);
         Dictionary<TKey, TElement> ToDictionary<TElement>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TElement>> elementSelector);
+        /// <summary>
+        ///  执行SQL查询，返回指定字段的记录的第一条记录，记录不存在时返回 TReturn 默认值
+        /// </summary>
+        /// <typeparam name="TReturn"></typeparam>
+        /// <param name="select"></param>
+        /// <returns></returns>
+        TReturn First<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select);
 
         /// <summary>
         /// 【linq to sql】专用方法，不建议直接使用

FreeSql/Internal/CommonProvider/SelectProvider/Select1Provider.cs

@@ -1154,6 +1154,7 @@ namespace FreeSql.Internal.CommonProvider
                             var tbrefMid = _commonUtils.GetTableByEntity(tbref.RefMiddleEntityType);
                             var tbrefMidName = _tableRules?.FirstOrDefault()?.Invoke(tbref.RefMiddleEntityType, tbrefMid.DbName) ?? tbrefMid.DbName;
                             var sbJoin = new StringBuilder().Append($"{_commonUtils.QuoteSqlName(tbrefMidName)} midtb ON ");
+                            if (_orm.CodeFirst.IsAutoSyncStructure && tbrefMid.Type != typeof(object)) _orm.CodeFirst.SyncStructure(tbrefMid.Type, tbrefMidName);
                             for (var z = 0; z < tbref.RefColumns.Count; z++)
                             {
                                 if (z > 0) sbJoin.Append(" AND ");

FreeSql/Internal/CommonProvider/SelectProvider/SelectGroupingProvider.cs

@@ -329,6 +329,7 @@ namespace FreeSql.Internal.CommonProvider
         }
 
         public List<TReturn> Select<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select) => ToList(select);
+        public TReturn First<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select) => ToList<TReturn>(select).FirstOrDefault();
         public List<TReturn> ToList<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select)
         {
             _lambdaParameter = select?.Parameters[0];
@@ -344,6 +345,7 @@ namespace FreeSql.Internal.CommonProvider
 #else
         async public Task<long> CountAsync(CancellationToken cancellationToken = default) => _select._cancel?.Invoke() == true ? 0 : long.TryParse(string.Concat(await _orm.Ado.ExecuteScalarAsync(_select._connection, _select._transaction, CommandType.Text, $"select count(1) from ({this.ToSql($"1{_comonExp._common.FieldAsAlias("as1")}")}) fta", _select._commandTimeout, _select._params.ToArray(), cancellationToken)), out var trylng) ? trylng : default(long);
 
+        async public Task<TReturn> FirstAsync<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select, CancellationToken cancellationToken = default) => (await ToListAsync<TReturn>(select, cancellationToken)).FirstOrDefault();
         public Task<List<TReturn>> ToListAsync<TReturn>(Expression<Func<ISelectGroupingAggregate<TKey, TValue>, TReturn>> select, CancellationToken cancellationToken = default)
         {
             var map = new ReadAnonymousTypeInfo();