Converting Sql server query to MySql query

I am trying to convert Query from sql server to MySql. My query in Sql is like below:

WITH ChildCategories (ParentID, categoryID, Level)
AS
(
    SELECT e.ParentID, e.CategoryID, 0 AS Level
    FROM dbo.Category AS e
    WHERE ParentID=195
    UNION ALL
    SELECT e.ParentID, e.CategoryID, Level + 1
    FROM dbo.Category AS e
    INNER JOIN ChildCategories AS d
        ON e.ParentID = d.categoryID
)
Select 195 as categoryID
UNION 
select CategoryID from ChildCategories

And I tried to convert above query in MySql like below:

select CategoryID, Name,( @pv:=t.ParentID,t.CategoryID) as ParentID 
    from (select CategoryID, Name, ParentID from Category order by CategoryID     desc) t 
    join (select @pv:=196)tmp on t.CategoryID=@pv 
    order by ParentID;

But am getting this error:

Operand should contain 1 column(s)

Can anyone help on this? Thanks in advance.

Copyright Notice：Content Author:「Rekha S」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/38763704/converting-sql-server-query-to-mysql-query