how to understand the set function in this situation?

[sdtfll]

dbo.Person table: 

id name

1 Grant

2  Jim

3   Bob

--------------------------------------------------------------------------------------

set a = 1,2;

names:

load id,name;

SQL select id,name 

FROM dbo.Person WHERE id IN ($(a));   // output: 1 Grant ; 2 Jim

set a = Grant, Jim;

names:

load id,name;

SQL select id,name 

FROM dbo.Person WHERE name IN ($(a));   // failed

[Saravanan_Desingh · Accepted solution]

Try this,

set a = 'Grant','Jim';

names:
load id,name;
SQL select id,name 
FROM dbo.Person WHERE name IN ($(a));

[sdtfll]

Perfect, it works now, thanks so much.