How to update rows with a given repeating number sequence.
my table is as follows
line_type
line_val
line_pattern
A
1
null
A
2
null
B
5
null
B
6
null
C
3
null
C
4
null
Now I want to update the column value with the repeating pattern of 8532
So the table after the update will look like
line_type
line_val
line_pattern
A
1
8
A
2
5
B
5
3
B
6
2
C
3
8
C
4
5
How can I achieve this in a update statement ?
With the data you have provided it is not possible to satisfy your requirement. The data in a table is not stored in a specific order. If you want the order to be guaranteed in a select statement, you need to provide an ORDER BY clause.
In the code below there is an additional column "ORDER_BY" to specify the order in which the records need to be processed. The repeating pattern is calculated using the MOD function to convert the row number to a repeating sequence of 4 numbers and then CASE maps each of those numbers to its respective pattern location.
WITH test_data (order_by, line_type, line_val)
AS
(
SELECT 1, 'A',1 FROM DUAL UNION ALL
SELECT 2, 'A',2 FROM DUAL UNION ALL
SELECT 3, 'B',5 FROM DUAL UNION ALL
SELECT 4, 'B',6 FROM DUAL UNION ALL
SELECT 5, 'C',3 FROM DUAL UNION ALL
SELECT 6, 'C',4 FROM DUAL
)
SELECT
CASE MOD(ROW_NUMBER() OVER (ORDER BY order_by),4)
WHEN 1 THEN 8
WHEN 2 THEN 5
WHEN 3 THEN 3
WHEN 0 THEN 2
END as line_pattern,
t.*
FROM
test_data t
LINE_PATTERN ORDER_BY L LINE_VAL
------------ ---------- - ----------
8 1 A 1
5 2 A 2
3 3 B 5
2 4 B 6
8 5 C 3
5 6 C 4
If you don't care about the order then use this form:
UPDATE mytable
SET line_pattern =
CASE MOD (ROWNUM, 4)
WHEN 1 THEN 8
WHEN 2 THEN 5
WHEN 3 THEN 3
WHEN 0 THEN 2
END
Related
Im trying to extract the following information from the oracle table below: A list of all the unique pairwise Status combinations for entries and their referenced entries. Entries with no referenced entry will be ignored. For example, for the entry 10 I expect the output to be (1,3) because its status is 1 and the status of the referenced entry 7 is 3. If the list doesn't already have this combination, it should be added to the list. Can anyone guide me in the right direction? I'm totally clueless as to how to even google what I want to achieve.
EDIT: The first column is the ID of the entry, the second column is the status of the entry, and the third column is the ID of another entry in the same table that is referenced.
Looks like a self join:
Sample data:
SQL> with test (id, status, ref_id) as
2 (select 1, 0, null from dual union all
3 select 2, 1, 3 from dual union all
4 select 3, 3, null from dual union all
5 select 4, 6, 6 from dual union all
6 select 5, 0, 1 from dual union all
7 select 6, 4, null from dual union all
8 select 7, 3, null from dual union all
9 select 8, 5, 9 from dual union all
10 select 9, 2, null from dual union all
11 select 10, 1, 7 from dual
12 )
Query:
13 select a.id, a.status, b.status
14 from test a join test b on b.id = a.ref_id
15 where a.ref_id is not null
16 order by a.id;
ID STATUS STATUS
---------- ---------- ----------
2 1 3
4 6 4
5 0 0
8 5 2
10 1 3
SQL>
If you want to get distinct pairs (but still know IDs involved), you could use listagg (it'll work as long as resulting string doesn't exceed 4000 characters; if it does, use xmlagg instead):
13 select listagg(a.id, ', ') within group (order by a.id) id,
14 a.status, b.status
15 from test a join test b on b.id = a.ref_id
16 where a.ref_id is not null
17 group by a.status, b.status
18 order by id;
ID STATUS STATUS
-------------------- ---------- ----------
2, 10 1 3
4 6 4
5 0 0
8 5 2
SQL>
If you don't care about IDs, then
13 select distinct a.status, b.status
14 from test a join test b on b.id = a.ref_id
15 where a.ref_id is not null
16 order by a.status, b.status;
STATUS STATUS
---------- ----------
0 0
1 3
5 2
6 4
SQL>
Sorry for a little bit confuse on the title.
I would like to use SQL for join sequence table as below
Original Table Records
3
3
4
1
Result Table
1
2
3
1
2
3
1
2
3
4
1
Based on comment you posted,
sample data:
SQL> with test (col) as
2 (select 3 from dual union all
3 select 3 from dual union all
4 select 4 from dual union all
5 select 1 from dual
6 )
Query begins here:
7 select column_value
8 from test cross join
9 table(cast(multiset(select level from dual
10 connect by level <= col
11 ) as sys.odcinumberlist));
COLUMN_VALUE
------------
1
2
3
1
2
3
1
2
3
4
1
11 rows selected.
SQL>
I would like to know if the following is possible
For example I have a shoe factory. In this factory I have a production line, Every step in this production line is recorded into the oracle database.
if the shoe has completed a production step the result is = 1
example table
Shoe_nr production step result
1 1 1
1 2 1
1 3
2 1 1
2 2 1
2 3
3 1
3 2
3 3
Now the question, is it possible to filter out production step 3 where only the shoes have passed production step 2 which is equal to 1 in result.
I know if it can be done it's probably very easy but if you dont know i found out it's a little bit tricky.
Thanks,
Chris
Yes, you can do it with IN and a Subselect
select *
from shoes
where shoe.id in (
select shoe.id
from shoes
where production_step = 2
and result = 1
)
and production_step = 3
This might be one option; see comments within code (lines #1 - 12 represent sample data; you already have that and don't type it. Query you might be interested in begins at line #13).
SQL> with shoes (shoe_nr, production_step, result) as
2 -- sample data
3 (select 1, 1, 1 from dual union all
4 select 1, 2, 1 from dual union all
5 select 1, 3, null from dual union all
6 select 2, 1, 1 from dual union all
7 select 2, 2, 1 from dual union all
8 select 2, 3, null from dual union all
9 select 3, 1, null from dual union all
10 select 3, 2, null from dual union all
11 select 3, 3, null from dual
12 ),
13 -- which shoes' production step #3 should be skipped?
14 skip as
15 (select shoe_nr
16 from shoes
17 where production_step = 2
18 and result = 1
19 )
20 -- finally:
21 select a.shoe_nr, a.production_step, a.result
22 from shoes a
23 where (a.shoe_nr, a.production_step) not in (select b.shoe_nr, 3
24 from skip b
25 )
26 order by a.shoe_nr, a.production_step;
SHOE_NR PRODUCTION_STEP RESULT
---------- --------------- ----------
1 1 1
1 2 1
2 1 1
2 2 1
3 1
3 2
3 3
7 rows selected.
SQL>
If you just want the shoe_nr that satisfy the condition, you can use aggregation and a having clause:
select shoe_nr
from mytable
group by shoe_nr
having
max(case when production_step = 2 then result end) = 0
and max(case when production_step = 3 then 1 end) = 1
If you want the entire row corresponding to this shoe_nr at step 3, use window functions instead:
select 1
from (
select
t.*,
max(case when production_step = 2 then result end)
over(partition by shoe_nr) as has_completed_step_2
from mytable t
) t
where production_step = 3 and has_completed_step_2 = 0
Consider the following table:
ID Feature
1 1
1 2
1 3
2 3
2 4
2 6
3 5
3 10
3 12
4 12
4 18
5 10
5 30
I would like to group the individuals based on overlapping features. If two of these groups again have overlapping features, I would consider both as one group. This process should be repeated until there are no overlapping features between groups. The result of this procedure on the table above would be:
ID Feature Flag
1 1 A
1 2 A
1 3 A
2 3 A
2 4 A
2 6 A
3 5 B
3 10 B
3 12 B
4 12 B
4 18 B
5 10 B
5 30 B
So actually the problem I am trying to solve is finding connected components in a graph. Here [1,2,3] is the graph with ID 1 (see https://en.wikipedia.org/wiki/Connectivity_(graph_theory)). The problem is equivalent to this problem, however I would like to solve it with Oracle SQL.
Here is one way to do this, using a hierarchical ("connect by") query. The first step is to extract the initial relationships from the base data; the hierarchical query is built on the result from this first step. I added one more row to the inputs to illustrate a node that is a connected component by itself.
You marked the connected components as A and B - of course, that won't work if you have, say, 30,000 connected components. In my solution, I use the minimum node name as the marker for each connected component.
with
sample_data (id, feature) as (
select 1, 1 from dual union all
select 1, 2 from dual union all
select 1, 3 from dual union all
select 2, 3 from dual union all
select 2, 4 from dual union all
select 2, 6 from dual union all
select 3, 5 from dual union all
select 3, 10 from dual union all
select 3, 12 from dual union all
select 4, 12 from dual union all
select 4, 18 from dual union all
select 5, 10 from dual union all
select 5, 30 from dual union all
select 6, 40 from dual
)
-- select * from sample_data; /*
, initial_rel(id_base, id_linked) as (
select distinct s1.id, s2.id
from sample_data s1 join sample_data s2
on s1.feature = s2.feature and s1.id <= s2.id
)
-- select * from initial_rel; /*
select id_linked as id, min(connect_by_root(id_base)) as id_group
from initial_rel
start with id_base <= id_linked
connect by nocycle prior id_linked = id_base and id_base < id_linked
group by id_linked
order by id_group, id
;
Output:
ID ID_GROUP
------- ----------
1 1
2 1
3 3
4 3
5 3
6 6
Then, if you need to add the ID_GROUP as a FLAG to the base data, you can do so with a trivial join.
My table has two integer columns: a and b. For each row, I want to select the nth smallest value of b among the rows with smaller a values. Here's a sample input/output, with n=2.
Input:
a | b
-------
1 | 4
2 | 2
3 | 5
4 | 3
5 | 9
6 | 1
7 | 7
8 | 6
9 | 0
Output:
a | 2th min b
-------------
1 | null ← only 1 element in [4], no 2nd min
2 | 4 ← 2nd min between [4,2]
3 | 4 ← 2nd min between [4,2,5]
4 | 3 ← 2nd min between [4,2,5,3]
5 | 3 ← etc.
6 | 2
7 | 2
8 | 2
9 | 1
I used n=2 here to keep it simple, but in practice, I want the 2000th smallest value (or some other large-ish constant). The column a can be assumed to contain distinct integers (and even 1, 2, 3, … if that's easier).
The problem is that if I use ORDER BY b in my window clause and NTH_VALUE, it just computes the answer on the wrong set of values:
WITH data AS (
SELECT 1 AS a, 4 AS b
UNION ALL SELECT 2 AS a, 2 AS b
UNION ALL SELECT 3 AS a, 5 AS b
UNION ALL SELECT 4 AS a, 3 AS b
UNION ALL SELECT 5 AS a, 9 AS b
UNION ALL SELECT 6 AS a, 1 AS b
)
SELECT nth_value(b, 2) over (order by a)
from data
returns [null, 2, 2, 2, 2, 2]: the values are ordered by a (so in the same order than they appear), so the value b=2 is always the one in second place. I want to order by a and then take the nth smallest value of b. Any idea how to write this in BigQuery (preferably Standard SQL)?
Below is for BigQuery Standard SQL and produces correct result for given example.
#standardSQL
WITH `project.dataset.table` AS (
SELECT 1 a, 4 b UNION ALL
SELECT 2, 2 UNION ALL
SELECT 3, 5 UNION ALL
SELECT 4, 3 UNION ALL
SELECT 5, 9 UNION ALL
SELECT 6, 1 UNION ALL
SELECT 7, 7 UNION ALL
SELECT 8, 6 UNION ALL
SELECT 9, 0
)
SELECT
a,
(SELECT b FROM
(SELECT b FROM UNNEST(c) b ORDER BY b LIMIT 2)
ORDER BY b DESC LIMIT 1
) b2
FROM (
SELECT a, IF(ARRAY_LENGTH(c) > 1, c, [NULL]) c
FROM (
SELECT a, ARRAY_AGG(b) OVER (ORDER BY a) c
FROM `project.dataset.table`
)
)
-- ORDER BY a
with expected result as below
Row a b2
1 1 null
2 2 4
3 3 4
4 4 3
5 5 3
6 6 2
7 7 2
8 8 2
9 9 1
Note: to make it work for 2000th element you might change 2 to 2000 in LIMIT 2
meantime, i can admit it looks a little ugly/messy to me and not sure about scalability but you can give it a shot
Quick Update
Below is a little less ugly looking version (same output of course)
#standardSQL
WITH `project.dataset.table` AS (
SELECT 1 a, 4 b UNION ALL
SELECT 2, 2 UNION ALL
SELECT 3, 5 UNION ALL
SELECT 4, 3 UNION ALL
SELECT 5, 9 UNION ALL
SELECT 6, 1 UNION ALL
SELECT 7, 7 UNION ALL
SELECT 8, 6 UNION ALL
SELECT 9, 0
)
SELECT a, c[SAFE_ORDINAL(2)] b2 FROM (
SELECT x.a, ARRAY_AGG(y.b ORDER BY y.b LIMIT 2) c
FROM `project.dataset.table` x
CROSS JOIN `project.dataset.table` y
WHERE y.a <= x.a
GROUP BY x.a
)
-- ORDER BY a
For 2000th element replace 2 to 2000 in LIMIT 2 and SAFE_ORDINAL(2)
Still potentially same issue with scalability because of (now) explicit CROSS JOIN