Hi, Sergei!
On Mon, Feb 4, 2019 at 11:49 PM Sergei Golubchik
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy index 10535326ce5..545c8f831b9 100644 --- a/sql/sql_yacc.yy +++ b/sql/sql_yacc.yy @@ -8190,6 +8195,10 @@ alter_list_item: { Lex->alter_info.flags|= ALTER_ADD_PERIOD; } + | ADD period_for_application_time
where's ADD PERIOD if_not_exists?
Not very clean with the behavior expected. Consider CREATE TABLE t (s date, e date, period for a(s,e)); Should ALTER TABLE ADD IF NOT EXISTS PERIOD FOR b replace PERIOD FOR a, or return ER_MORE_THAN_ONE_PERIOD?
ER_MORE_THAN_ONE_PERIOD of course. It adds a period name `b`, it's a different period, and there can be only one. So - an error.
If it'd be
ALTER TABLE ADD IF NOT EXISTS PERIOD FOR a(....)
it'd be a no-op.
I cannot see of a case when ALTER TABLE ADD IF NOT EXISTS should replace stuff.
Made it ADD PERIOD IF NOT EXISTS FOR a(....) First, it is more consistent with the way other entities handled, e.g. ADD CONSTRAINT IF NOT EXISTS; second, no shift/reduce conflicts:) -- Yours truly, Nikita Malyavin