I have a table with these columns
create table demo (
ID integer not null,
INDEX integer not null,
DATA varchar2(10)
)
Example data:
ID INDEX DATA
1 1 A
1 3 B
2 1 C
2 1 D
2 5 E
I want:
ID INDEX DATA
1 1 A
1 2 B -- 3 -> 2
2 1 C or D -- 1 -> 1 or 2
2 2 D or C -- 1 -> 2 or 1
2 3 E -- 5 -> 3 (closing the gap)
Is there a way to renumber the INDEX per ID using a single SQL update? Note that the order of items should be preserved (i.e. the item "E" should still be after the items "C" and "D" but the order of "C" and "D" doesn't really matter.
The goal is to be able to create a primary key over ID and INDEX.
If that matters, I'm on Oracle 10g.
MERGE
INTO demo d
USING (
SELECT rowid AS rid, ROW_NUMBER() OVER (PARTITION BY id ORDER BY index) AS rn
FROM demo
) d2
ON (d.rowid = d2.rid)
WHEN MATCHED THEN
UPDATE
SET index = rn
Related
Suppose I have a table as follows:
id=`A`B`A`B`B`B`A
item= 10 1 1 3 5 10 6
t=table(id,item)
id item
-- ----
A 10
B 1
A 1
B 3
B 5
B 10
A 6
For example, I want to sort the table with two conditions: first, by the most commonly occurring item in column item, then by the highest number in column item.
How can I sort like this:
id item
--- ----
A 10
B 10
A 1
B 1
A 6
B 5
B 3
Is there any way to go about this? Thanks!
Try this:
t1=table(id,item);
update t1 set count=count(item) context by item;
select * from t1 order by count desc, item desc;
I have a table (table1) with 3 column (ID,V,R), I want to divide it to some table based on ID. for example suppose it is a table1:
ID V R
1 1 T
1 2 F
2 1 T
2 3 T
3 4 F
then because I have 3 type of ID (which it could be more or less) I want 3 different table like this:
table1_1:
ID V R
1 1 T
1 2 F
table 1_2:
ID V R
2 1 T
2 3 T
table 1_3:
ID V R
3 4 F
is there any solution to do it in Laravel?
I apologize in advance if my question is so simple.
I have a data-set in which there are duplicate IDs in the first column. I'm hoping to obtain a single row of data for each ID based on the second column's value. The data looks like so:
ID Info_Source Prior?
A 1 Y
A 3 N
A 2 Y
B 1 N
B 1 N
B 2 Y
C 2 N
C 3 Y
C 1 N
Specifically the criteria would call for prioritizing based on the second column's value (3 highest priority; then 1; and lastly 2): if the 'Info_Source' column has a value of 3, return that row; if there is no 3 in the second column for a given ID, look for a 1 and if found return that row; and finally if there is no 3 or 1 associated with the ID, search for 2 and return that row for the ID.
The desired results would be a single row for each ID, and the resulting data would be:
ID Info_Source Prior?
A 3 N
B 1 N
C 3 Y
row_number() over() usually solves these needs nicely and efficiently e.g.
select ID, Info_Source, Prior
from (
select ID, Info_Source, Prior
, row_number() over(partition by id order by Info_source DESC) as rn
)
where rn = 1
For prioritizing the second column's value (3 ; then 1, then 2) use a case expression to alter the raw value into an order that you need.
select ID, Info_Source, Prior
from (
select ID, Info_Source, Prior
, row_number() over(partition by id
order by case when Info_source = 3 then 3
when Infor_source = 1 then 2
else 1 end DESC) as rn
)
where rn = 1
Consider, I have the following in a select query:
ID Flag
5 Y
5 Y
5 N
6 Y
6 Y
6 Y
6 N
I should be adding a new column count in the same select which counts the number of 'Y' records for the ID and assigns it to all. (Eg: ID=5 has 3 records. All of them should be assigned the count value as '2').
Output required in select query:
ID Flag count
5 Y 2
5 Y 2
5 N 2
6 Y 3
6 Y 3
6 Y 3
6 N 3
Use a window function:
select id,
flag,
count(case when flag = 'Y' then 1 end) over (partition by id) as "count"
from the_table
order by id;
The case expression will return null for flags with N and thus they will be ignored by the count() function
---------------
MASTER TABLE
---------------
DATA_KEY NUMBER
TEXT VARCHAR2(2000)
ORDER_NO NUMBER
---------------
DETAIL TABLE
---------------
DATA_KEY NUMBER
SIMILAR_DATA_KEY NUMBER
DISTANCE_COUNT NUMBER
---------------
INSERT QUERY
---------------
INSERT INTO DETAIL
(
SELECT DATA_KEY, SIMILAR_DATA_KEY, DISTANCE_COUNT
FROM
(
SELECT A.DATA_KEY AS DATA_KEY, B.DATA_KEY AS SIMILAR_DATA_KEY,
UTL_MATCH.EDIT_DISTANCE(A.TEXT, B.TEXT) AS DISTANCE_COUNT
FROM
(SELECT DATA_KEY, TEXT, ORDER_NO FROM MASTER) A
INNER JOIN
(SELECT DATA_KEY, TEXT, ORDER_NO FROM MASTER) B
ON (A.ORDER_NO < B.ORDER_NO)
)
WHERE DISTANCE_COUNT <= 5
)
I need compare MASTER table TEXT field with other TEXT field.
indexes are not exist.
master table 90,000 rows.
ORDER_NO field is for avoid duplicated compare. (1 .. 90000)
=============================================================
A.ORDER_NO < B.ORDER_NO
------------------------------------------
1, 1 <- exclude
1, 2 <- join
1, 3 <- join
1, 4 <- join
..
2, 1 <- exclude
2, 2 <- exclude
2, 3 <- join
2, 4 <- join
...
3, 1 <- exclude
3, 2 <- exclude
3, 3 <- exclude
3, 4 <- join
1. NOT need compare 1 and 1
2. Need compare 1 and 2
3. NOT need compare 2 and 1 (because, duplicate 2.)
so, for decrease compare count...
=============================================================
Slow zone is (WHERE DISTANCE_COUNT <= 5) ?
Slow zone is comparing rows (90000*89999/2) ?
Query elapse time is 7 days.
6,000 rows inserted to DETAIL table.
How to speed up?
I'm sorry for poor English...