Does “select for update” prevent other connections inserting when the row is not present

Question

I\'m interested in whether a select for update query will lock a non-existent row.

e.g.

Table FooBar with two columns, foo and bar, foo has a un

Answer 1

On Oracle:

Session 1

create table t (id number);
alter table t add constraint pk primary key(id);

SELECT *
FROM t
WHERE id = 1
FOR UPDATE;
-- 0 rows returned
-- this creates row level lock on table, preventing others from locking table in exclusive mode

Session 2

SELECT *
FROM t 
FOR UPDATE;
-- 0 rows returned
-- there are no problems with locking here

rollback; -- releases lock


INSERT INTO t
VALUES (1);
-- 1 row inserted without problems