How to select all data from a table to a structure using one select statement?

A structure is something flat, is like a table with only one line. So you cannot have a whole table inside a structure.

You have to declare a table

SELECT * from /brlt/subsc 
       INTO TABLE @DATA(dup_table) 
       WHERE Type = @ls_request_input_data-Type 
       AND    Dl1 = @ls_request_input_data-Dl1.

or use your statement, because it is the right way to read a table in a structure

Hello Amit Krishna,

SELECT.. ENDSELECT is Loop which will basically fetch one entry at a time until the last entry is reached. It is considered as a client cursor that will induce a lot of work load on the communication between Application and Database server. It is not a recommended approach as well. You can proceed with the code suggested by Frederic Girod.

Regards!