Update table with While loop reading id first - sql-server

Question

I just wanted to ask something, I want to update a table, but this table 300k rows, it is taking about 1.8 - 2.3 seconds per row this is the table I need to update, if name match with a column i need to set the value of column All,
ID |cexp_cod |All |name |New |Normal |Vip
1 |13 |9 |Vip |NULL |NULL |NULL
2 |16 |9 |Vip |NULL |NULL |NULL
3 |16 |6 |Normal |NULL |NULL |NULL
4 |18 |9 |Vip |NULL |NULL |NULL
5 |23 |9 |New |NULL |NULL |NULL
6 |25 |9 |New |NULL |NULL |NULL
7 |26 |9 |Vip |NULL |NULL |NULL
8 |27 |9 |New |NULL |NULL |NULL
9 |40 |9 |Vip |NULL |NULL |NULL
10 |43 |9 |Vip |NULL |NULL |NULL
11 |43 |6 |Normal |NULL |NULL |NULL
and this is my query:
DECLARE #loop smallint = 0
,#v_xp_cod varchar(max) = 0
,#v_name varchar(MAX) = NULL
,#v_pond varchar(max) = 0
,#v_id bigint = 0
WHILE #loop = 0
BEGIN
SELECT TOP 1 #v_xp_cod = query01.xp_cod
,#v_name = query01.name
,#v_pond = query01.All
,#v_id = query01.ID
FROM (
SELECT xp_cod
, name
, All
, ID
FROM temp WITH(NOLOCK)
) AS query01
WHERE query01.ID > #v_id
ORDER BY query01.ID ASC
IF ##rowcount=0
BEGIN
SET #loop=1
END
ELSE -- update
BEGIN
DECLARE #i_update nvarchar(MAX)=null
SELECT #i_update = 'UPDATE temp
SET [' +#v_name+ '] = '+#v_pond+'
WHERE xp_cod = ' + #v_xp_cod
EXECUTE sp_executesql #i_update
END
END

Answer 1

Perhaps try rewriting the query using a different approach or format:
UPDATE MyTable
SET MyColumnName =
( SELECT table2.Name
FROM table2
WHERE table2.my_id = MyTable.id)
WHERE EXISTS
( SELECT table2.Name
FROM table2
WHERE table2.my_id = MyTable.id);