Question

In SQL, while inserting into a presorted table, is it possible to insert a row while sorting the row along with the entire table? Such as

create table positional_order (
  num number,
  txt varchar2(10)
);

existing table

row 1   (3, 'three' );
row 2   (4, 'four' );

insert a new row

row 3   (1, 'one');

after the insert

table becomes

row 1   (1, 'one');
row 2   (3, 'three' );
row 3   (4, 'four' );

Is this possible?

Or I have to insert the row into the table and then do select order by ?

Btw I am using sqlite.

Thanks,

Answer 1

Short answer: Tables are sets and do not have an order.

Long answer: A clustered index is as close as it comes, and even that isn’t really all that close — w/o an order by, the query engine is free to return the results in any order it thinks best. A clustered index will mean that a query on just that table will most LIKELY return the rows in the order defined for the index, but don’t count on it. Now, that said, all indexes define A order and a clustered index defines an order of the records on disk, while this doesn’t guarantee your results in any particular order it does make it likely under most circumstances. But I would consider carefully before using a clustered index on anything but an auto generated/incremented column. If you insert into a table with a clustered index, records on disk may have to be relocated, and thats an expensive operation.