- 增加 .First()/.FirstAsync() 指定字段查询的重载方法；

- 调整 FreeSql.Repository 直接引用 FreeSql.DbContext 内的仓储实现；
- 补充 单独针对 MySql 枚举类型的单元测试；

FreeSql/FreeSql.csproj

@@ -2,7 +2,7 @@
 
 	<PropertyGroup>
 		<TargetFramework>netstandard2.0</TargetFramework>
-		<Version>0.4.10</Version>
+		<Version>0.4.11</Version>
 		<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
 		<Authors>YeXiangQin</Authors>
 		<Description>FreeSql is the most convenient ORM in dotnet. It supports Mysql, Postgresql, SqlServer, Oracle and Sqlite.</Description>

FreeSql/Interface/Curd/ISelect/ISelect1.cs

@@ -30,6 +30,25 @@ namespace FreeSql {
 		/// <returns></returns>
 		List<TReturn> ToList<TReturn>(Expression<Func<T1, TReturn>> select);
 		Task<List<TReturn>> ToListAsync<TReturn>(Expression<Func<T1, TReturn>> select);
+
+		/// <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">返回类型</typeparam>
+		/// <param name="select">选择列</param>
+		/// <returns></returns>
+		TReturn ToOne<TReturn>(Expression<Func<T1, TReturn>> select);
+		Task<TReturn> ToOneAsync<TReturn>(Expression<Func<T1, TReturn>> select);
+
+		/// <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">返回类型</typeparam>
+		/// <param name="select">选择列</param>
+		/// <returns></returns>
+		TReturn First<TReturn>(Expression<Func<T1, TReturn>> select);
+		Task<TReturn> FirstAsync<TReturn>(Expression<Func<T1, TReturn>> select);
+
 		/// <summary>
 		/// 返回即将执行的SQL语句
 		/// </summary>

FreeSql/Internal/CommonProvider/SelectProvider/Select1Provider.cs

@@ -228,5 +228,13 @@ namespace FreeSql.Internal.CommonProvider {
 		public bool Any(Expression<Func<T1, bool>> exp) => this.Where(exp).Any();
 
 		public Task<bool> AnyAsync(Expression<Func<T1, bool>> exp) => this.Where(exp).AnyAsync();
+
+		public TReturn ToOne<TReturn>(Expression<Func<T1, TReturn>> select) => this.Limit(1).ToList(select).FirstOrDefault();
+
+		async public Task<TReturn> ToOneAsync<TReturn>(Expression<Func<T1, TReturn>> select) => (await this.Limit(1).ToListAsync(select)).FirstOrDefault();
+
+		public TReturn First<TReturn>(Expression<Func<T1, TReturn>> select) => this.ToOne(select);
+
+		public Task<TReturn> FirstAsync<TReturn>(Expression<Func<T1, TReturn>> select) => this.ToOneAsync(select);
 	}
 }