Unable to retrieve value returned from mysql function

Since a week am working with MYSQL , got to execute the Stored Procedure as well as Views but Facing some problem retrieving the values returned from a function. Here's the Function:

      CREATE DEFINER=`root`@`localhost` FUNCTION `GetProductIdsStringByEnquiryId`
         (
         InEnquiryId int
         ) RETURNS varchar(4000) CHARSET utf8
      BEGIN
        DECLARE InProductIds varchar(4000);
        DECLARE ProductId varchar(50);
        DECLARE x,y,z INT;
        DECLARE sp1_cursor CURSOR FOR SELECT ProductId FROM enquiryproductid where 
          EnquiryId=InEnquiryId;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET z = 1;
        SET InProductIds='';
        OPEN sp1_cursor;
        REPEAT
        FETCH sp1_cursor INTO ProductId;
        SETInProductIds=concat(InProductIds,ProductId,',');
        UNTIL (z=1)
        END REPEAT;
        CLOSE sp1_cursor;
       RETURN InProductIds ;
     END

I was initially working with SQL SERVER 2005, and the function which I have written in their I tried converting it as above in MYSQL, Here's the SQL Function Code:

       CREATE function [dbo].[GetBranchIdsStringByEmployeeId]
        (
    @EmployeeId as integer
         )
       returns nvarchar(4000)
      as
      begin
  declare @BranchIds as nvarchar(4000)
  set @BranchIds=''
  if exists(select 1 from dbo.BranchEmployees where EmployeeId=@EmployeeId)
    begin
        select @BranchIds=@BranchIds+cast(BranchId as nvarchar(50))
                      +','   from dbo.BranchEmployees where EmployeeId=@EmployeeId
                       order by BranchId
    end
return @BranchIds
       end

Can anybody Please Let me know if the Function What I have written开发者_如何学运维 in MYSQL is in ProperManner or not? Please do help me out. Thank You.

Not read fully through it, but few comments

Variable assignment in mysql uses := (in set @variable it is ok to use =, in select @variable:=@variable+1)

Are you trying to

SELECT group_concat(BranchId)
FROM dbo.BranchEmployees
WHERE EmployeeId = @EmployeeId

?