SQLite-将表更新为顺序编号行

Question

I have table like this:

CREATE TABLE Scan
(Id Integer,
Ordinal Integer)

INSERT Scan VALUES(10, 1)
INSERT Scan VALUES(20, 1)
INSERT Scan VALUES(30, 8)
INSERT Scan VALUES(40, 10)

I'd like to update Ordinal column so all the numbers become sequential like so(in case of duplicate Ordinal order by Id):

Id Ordinal
10 1
20 2
30 3
40 4

Is it possible with plain SQL in SQLite?

Answer 1

SQLite doesn't really have a good way of doing this. Here is one approach that isn't particularly efficient:

update scan
    set ordinal = (select count(*)
                   from scan s2
                   where s2.ordinal < scan.ordinal or
                         s2.ordinal = scan.ordinal and s2.id <= scan.id
                  );