Code to get list of all the columns in comma separated format

Below given simple sql query will give the column list of the table1 in comma separated format.

DECLARE @ColumnList varchar(max)

SELECT @ ColumnList  = COALESCE(@EmployeeList + ', ', '') + 
   CAST(column_name AS varchar(100))
FROM Information_schema.columns where table_name = 'Table1'

Print @ ColumnList 

Note : Replace table1 with your table name.