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Allow first/last value functions to have frame definitions

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Add a test case to check this behavior.
This commit is contained in:
Vicențiu Ciorbaru
2016-09-21 16:45:36 +02:00
parent 74fa10645e
commit 872c0b4225
3 changed files with 12 additions and 77 deletions
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75
mysql-test/r/win_first_last_value.result
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@ -1,75 +0,0 @@
create table t1 (
pk int primary key,
a int,
b int,
c char(10),
d decimal(10, 3),
e real
);
insert into t1 values
( 1, 0, 1, 'one', 0.1, 0.001),
( 2, 0, 2, 'two', 0.2, 0.002),
( 3, 0, 3, 'three', 0.3, 0.003),
( 4, 1, 2, 'three', 0.4, 0.004),
( 5, 1, 1, 'two', 0.5, 0.005),
( 6, 1, 1, 'one', 0.6, 0.006),
( 7, 2, NULL, 'n_one', 0.5, 0.007),
( 8, 2, 1, 'n_two', NULL, 0.008),
( 9, 2, 2, NULL, 0.7, 0.009),
(10, 2, 0, 'n_four', 0.8, 0.010),
(11, 2, 10, NULL, 0.9, NULL);
select pk, first_value(pk) over (order by pk),
last_value(pk) over (order by pk)
from t1
order by pk desc;
pk first_value(pk) over (order by pk) last_value(pk) over (order by pk)
11 1 11
10 1 10
9 1 9
8 1 8
7 1 7
6 1 6
5 1 5
4 1 4
3 1 3
2 1 2
1 1 1
select pk,
first_value(pk) over (order by pk desc),
last_value(pk) over (order by pk desc)
from t1;
pk first_value(pk) over (order by pk desc) last_value(pk) over (order by pk desc)
1 11 1
2 11 2
3 11 3
4 11 4
5 11 5
6 11 6
7 11 7
8 11 8
9 11 9
10 11 10
11 11 11
select pk, a, b, c, d, e,
first_value(b) over (partition by a order by pk) as fst_b,
last_value(b) over (partition by a order by pk) as lst_b,
first_value(c) over (partition by a order by pk) as fst_c,
last_value(c) over (partition by a order by pk) as lst_c,
first_value(d) over (partition by a order by pk) as fst_d,
last_value(d) over (partition by a order by pk) as lst_d,
first_value(e) over (partition by a order by pk) as fst_e,
last_value(e) over (partition by a order by pk) as lst_e
from t1;
pk a b c d e fst_b lst_b fst_c lst_c fst_d lst_d fst_e lst_e
1 0 1 one 0.100 0.001 1 1 one one 0.100 0.100 0.001 0.001
2 0 2 two 0.200 0.002 1 2 one two 0.100 0.200 0.001 0.002
3 0 3 three 0.300 0.003 1 3 one three 0.100 0.300 0.001 0.003
4 1 2 three 0.400 0.004 2 2 three three 0.400 0.400 0.004 0.004
5 1 1 two 0.500 0.005 2 1 three two 0.400 0.500 0.004 0.005
6 1 1 one 0.600 0.006 2 1 three one 0.400 0.600 0.004 0.006
7 2 NULL n_one 0.500 0.007 NULL NULL n_one n_one 0.500 0.500 0.007 0.007
8 2 1 n_two NULL 0.008 NULL 1 n_one n_two 0.500 NULL 0.007 0.008
9 2 2 NULL 0.700 0.009 NULL 2 n_one NULL 0.500 0.700 0.007 0.009
10 2 0 n_four 0.800 0.01 NULL 0 n_one n_four 0.500 0.800 0.007 0.01
11 2 10 NULL 0.900 NULL NULL 10 n_one NULL 0.500 0.900 0.007 NULL
drop table t1;

11
sql/item_windowfunc.h
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@ -657,10 +657,19 @@ public:
case Item_sum::PERCENT_RANK_FUNC:
case Item_sum::CUME_DIST_FUNC:
case Item_sum::NTILE_FUNC:
return true;
default:
return false;
}
}
bool requires_special_cursors() const
{
switch (window_func()->sum_func()) {
case Item_sum::FIRST_VALUE_FUNC:
case Item_sum::LAST_VALUE_FUNC:
return true;
default:
default:
return false;
}
}

3
sql/sql_window.cc
View File

@ -2147,7 +2147,8 @@ void get_window_functions_required_cursors(
functions can keep the default frame generating code, overwrite it or
add to it.
*/
if (item_win_func->is_frame_prohibited())
if (item_win_func->is_frame_prohibited() ||
item_win_func->requires_special_cursors())
{
add_special_frame_cursors(thd, cursor_manager, item_win_func);
cursor_managers->push_back(cursor_manager);