Delete the 'first' record from a table in

Question

Is it possible to delete the 'first' record from a table in SQL Server, without using any WHERE condition and without using a cursor?

Answer 1

Does this really make sense?
There is no "first" record in a relational database, you can only delete one random record.

Answer 2

SQL-92:

DELETE Field FROM Table WHERE Field IN (SELECT TOP 1 Field FROM Table ORDER BY Field DESC)

Answer 3

Similar to the selected answer, a table source can be used, in this case a derived query:

delete from dd
from (
    select top 1 *
    from my_table
) dd

Feel free to add orderbys and conditions.

For the next example, I'll assume that the restriction on 'where' is due to not wanting to select a row based on its values. So assuming that we want to delete a row based on position (in this case the first position):

delete from dd
from (
    select
        *,
        row = row_number() over (order by (select 1))
    from my_table
) dd
where row = 1

Note that the (select 1) makes it the sort order that the tables or indexes are in. You can replace that with a newid to get fairly random rows.

You can also add a partition by to delete the top row of each color, for example.

Answer 4

No, AFAIK, it's not possible to do it portably.

There's no defined "first" record anyway - on different SQL engines it's perfectly possible that "SELECT * FROM table" might return the results in a different order each time.

Answer 5

WITH  q AS
        (
        SELECT TOP 1 *
        FROM    mytable
        /* You may want to add ORDER BY here */
        )
DELETE
FROM    q

Note that

DELETE TOP (1)
FROM   mytable

will also work, but, as stated in the documentation:

The rows referenced in the TOP expression used with INSERT, UPDATE, or DELETE are not arranged in any order.

Therefore, it's better to use WITH and an ORDER BY clause, which will let you specify more exactly which row you consider to be the first.

Answer 6

depends on your DBMS (people don't seem to know what that is nowadays)

-- MYSql:
DELETE FROM table LIMIT 1;
-- Postgres:
DELETE FROM table LIMIT 1;
-- MSSql:
DELETE TOP(1) FROM table;
-- Oracle:
DELETE FROM table WHERE ROWNUM = 1;