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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,
lead(pk) over (order by pk),
lead(pk, 1) over (order by pk),
lead(pk, 2) over (order by pk),
lead(pk, 0) over (order by pk),
lead(pk, -1) over (order by pk),
lead(pk, -2) over (order by pk)
from t1
order by pk asc;
select pk,
lag(pk) over (order by pk),
lag(pk, 1) over (order by pk),
lag(pk, 2) over (order by pk),
lag(pk, 0) over (order by pk),
lag(pk, -1) over (order by pk),
lag(pk, -2) over (order by pk)
from t1
order by pk asc;
select pk, pk - 2,
lag(pk, pk - 2) over (order by pk),
lead(pk, pk - 2) over (order by pk)
from t1
order by pk asc;
select pk, pk - 2,
lag(pk, pk + 2) over (order by pk),
lead(pk, pk + 2) over (order by pk)
from t1
order by pk asc;
select pk, a,
lead(pk) over (partition by a order by pk),
lead(pk, 1) over (partition by a order by pk),
lead(pk, 2) over (partition by a order by pk),
lead(pk, 0) over (partition by a order by pk),
lead(pk, -1) over (partition by a order by pk),
lead(pk, -2) over (partition by a order by pk)
from t1
order by pk asc;
select pk, a,
lag(pk) over (partition by a order by pk),
lag(pk, 1) over (partition by a order by pk),
lag(pk, 2) over (partition by a order by pk),
lag(pk, 0) over (partition by a order by pk),
lag(pk, -1) over (partition by a order by pk),
lag(pk, -2) over (partition by a order by pk)
from t1
order by pk asc;
select pk, a, pk - 2,
lag(pk, pk - 2) over (partition by a order by pk),
lead(pk, pk - 2) over (partition by a order by pk),
lag(pk, a - 2) over (partition by a order by pk),
lead(pk, a - 2) over (partition by a order by pk)
from t1
order by pk asc;
select pk, a, pk - 2,
lag(pk, pk + 2) over (partition by a order by pk),
lead(pk, pk + 2) over (partition by a order by pk),
lag(pk, a + 2) over (partition by a order by pk),
lead(pk, a + 2) over (partition by a order by pk)
from t1
order by pk asc;
select pk, a, b, c, d, e,
lag(a) over (partition by a order by pk),
lag(b) over (partition by a order by pk),
lag(c) over (partition by a order by pk),
lag(d) over (partition by a order by pk),
lag(e) over (partition by a order by pk)
from t1
order by pk asc;
select pk, a, b, a+b,
lag(a + b) over (partition by a order by pk)
from t1
order by pk asc;
select pk, a, b, a+b,
lag(a + b) over (partition by a order by pk) + pk
from t1
order by pk asc;
--echo #
--echo # MDEV-15204 - LAG function doesn't require ORDER BY in OVER clause
--echo #
--error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
select pk,
lag(pk, 1) over ()
from t1;
--error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
select pk,
lead(pk, 1) over ()
from t1;
drop table t1;
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