sqlserver 递归函数

ALTER  FUNCTION [dbo].[Fn_GetChildrenCode]
(	
	@ParentCode NVARCHAR(50) -- 父级code代码
)
RETURNS VARCHAR(max)--下级json
AS
BEGIN
	DECLARE @ReturnJson [varchar] (max)
	SET @ReturnJson = '['
	DECLARE @CS_Code NVARCHAR(50)--code
	DECLARE @CS_Name NVARCHAR(400)--小分类名称
	
	--开始游标code
	DECLARE curCode CURSOR FOR SELECT Name,Code FROM 表名 WHERE PCode = @ParentCode
	OPEN curCode
	FETCH NEXT FROM curCode INTO @CS_Name,@CS_Code
    WHILE ( @@FETCH_STATUS <> -1 )
    BEGIN      		
    		SET @ReturnJson = @ReturnJson + '{"value":"' + @CS_Code + '","label":"' + @CS_Name + '","children":' + dbo.Fn_GetChildrenCode(@CS_Code) + '},'    	
		FETCH NEXT FROM curCode INTO @CS_Name,@CS_Code
	END
		IF substring(@ReturnJson,len(@ReturnJson),1) = ','
			SET @ReturnJson = left(@ReturnJson,len(@ReturnJson)-1)
		SET @ReturnJson = @ReturnJson + ']'
	CLOSE curCode;
	DEALLOCATE curCode;
	--结束游标code
	RETURN @ReturnJson
END