Source table
| Row | A | B | C | D | 
|---|---|---|---|---|
| 1 | Code | Product | Colour | Price | 
| 2 | 1 | pen | red | 500 | 
| 3 | 2 | pen | blue | -50 | 
| 4 | 3 | pen | red | 0 | 
| 5 | 4 | pencil | blue | 17 | 
| 6 | 5 | pencil | green | -1.5 | 
to select all:
= QUERY(A1:D5, "select *")
or
= QUERY(A1:D5, "select A, B, C, D")
or convert data range into array and use this formula:
= QUERY({A1:D5}, "select Col1, Col2, Col3, Col4")