Question

I have a database with a table book (id, name, display, priority)

For example:

 ________________________________________________________
|    id    |    name    |    display    |    priority    |
 --------------------------------------------------------
|    1     |    test1   |     True      |       5        |
|    2     |    test2   |     True      |       3        |
|    3     |    test3   |     False     |       4        |
|    4     |    test4   |     True      |       1        |
|    5     |    test5   |     True      |       2        |
|    6     |    test6   |     False     |       1        |
|    7     |    test7   |     True      |       1        |
|    8     |    test8   |     True      |       4        |
|    9     |    test9   |     True      |       3        |
|    10    |    test10  |     False     |       2        |
|    11    |    test11  |     True      |       3        |
|    12    |    test12  |     True      |       5        |
 --------------------------------------------------------

I need to write a query to get only 3 rows with priority 1 and 2 and 3 and display is true

I use this stored procedure to display books that have priority 1 and 2 and 3 (the most specific books)

Problem:

1. when I try to select top 3 order by priority then the query get the first 3 rows with priority = 1, while I need 1-record with priority = 1 and 1-record with priority = 2 and 1-record with priority = 3.

2. when I try to get distinct book, distinct works over all records not on priority only

Result:

I need the result to be like:

 ________________________________________________________
|    id    |    name    |    display    |    priority    |
 --------------------------------------------------------
|    4     |    test4   |     True      |       1        |
|    2     |    test2   |     True      |       3        |
|    5     |    test5   |     True      |       2        |
 --------------------------------------------------------

How can I do that?

thanks for help

Answer 1

try this:

with cte as (
     select *,row_number() over(partition by priority  order by id) as row_num
     from book
     where  display='true'
     and priority in (1,2,3)
     )
select id,name,display,priority
from   cte 
where  row_num=1