Is it Possible to Merge Rows in SQL from Just One Column?

Question

I wonder if it is possible to merge multiple rows from just one column in SQL. Here's an example of my initial table:

Column 1 | Column 2 | Column 3
______________________________

DAVID    | 10.000   | Client 1
DAVID    | 5.000    | Client 2
DAVID    | 12.000   | Client 3
ANDREW   | 2.000    | Client 4
ANDREW   | 3.000    | Client 5

Here's my expected output:

Column 1 | Column 2 | Column 3
______________________________

DAVID    | 10.000   | Client 1
         | 5.000    | Client 2
         | 12.000   | Client 3
ANDREW   | 2.000    | Client 4
         | 3.000    | Client 5

I do not know if it's possible to have a table like the later one. So, any advice would be much appreciated.

Answer 1

This type of task is usually done in the presentation layer of the application rather than in the database.

But it can be done in SQL - provided that you have a column that defines the ordering of the rows! Say: id.

select
    case when row_number() over(partition by col1 order by id) = 1 then col1 end as col1,
    col2,
    col3
from mytable
order by col1, id