Hi gokuldas,
Refer below sample query.
Database
I have made use of the following table Customers with the schema as follows.
I have already inserted few records in the table.
You can download the database table SQL by clicking the download link below.
Download SQL file
SQL
SELECT * FROM
(
SELECT 'Select All' AS [Name]
UNION all
SELECT DISTINCT [Name]
FROM Customers
) t
ORDER BY CASE WHEN [Name] = 'Select ALL' THEN 0 ELSE 1 END
Screenshot