Table:
column 1 column 2 column 3
2 two 3
5 five 8
3 three 10
8 eight 11
12 one 15
I want to create a new column column 4like below:
column 1 column 2 column 3 column 4
2 two 3 three
5 five 8 eight
3 three 10
8 eight 11
12 one 15
I want to map column 3 and column 1 and if there's a match column 4 takes values of column 2.
Example: Value 3 in column 3 is present in column 1, so column 4 will take corresponding column 3 value three.
Thanks!
This looks like a left join:
select t.*, tt.column2 as column4
from table1 t left join
table1 tt
on t.column3 = tt.column1;
EDIT:
If you want to set the value, you can use update:
update table1 t
set column4 = (select tt.column2 from table1 tt where t.column3 = tt.column1)
where exists (select 1 from table1 tt where t.column3 = tt.column1);
However, this seems silly. You can easily get the value in the table using an explicit join or hiding the logic in a view.
I have the following tables:
Table I:
etu | nr |
1 2
2 2
2 3
2 1
3 4
3 9
Table A:
etu | rsp | nr
2 8 2
2 7 3
2 3 1
3 2 4
3 6 9
Now what I want to have as a result table is
etu | nr | rsp
2.. 3 7
3.. 9 6
So etu and nr are linked together and if multiple equal etu entries are available only the one with the highest nr is taken and the rsp value is added in the result table. in addition if more etu entries are available in the table I there are .. added to the etu value.
Explain: For the 3 9 6 row: The last row on table I is 3 9 so 3 is the number that is looked for and 9 is the highest number for the 3 rows. So we take that and add the rsp value for that ( 6 ) and we add that to the result table. For the 2 row it is the same 2 3 being the highest 2 row in table I.
I got something like:
select x.etu, x.rsp, y.nr from(
select i.etu etu, max(i.nr) maxnr, a.rsp from i left join a on
i.etu=a.etu and i.nr=a.nr group by etu)t
inner join a x on x.etu=t.etu and x.nr=t.nr inner join y on y.etu=t.etu
and y.nr=t.nr
or
select i.etu, max(i.nr) a.rsp from i left join a on i.etu=a.etu and
i.nr=a.nr grounp by
None even get me close to get the results that I want less add the .. after the etu when having the right result.
The system is DB10.5 Windows.
Thank you for all your help in advance.
Viking
I would use a CTE here like this:
with tmp as (
select i.etu, max(i.nr) as nt, count(*) as cnt
from i
group by i.etu)
select case
when tmp.cnt = 1 then char(a.etu)
else concat(rtrim(char(a.etu)), '..')
end as etu,
a.nr,
a.rsp
from tmp
left outer join a
on a.etu = tmp.etu
and a.nr = tmp.nr
The CTE provides the information necessary to join with a to get the correct response, and append the .. as necessary.
I have a table like in example below.
SQL> select * from test;
ID PARENT_ID NAME
1 1 A
2 1 B
3 2 A
4 2 B
5 3 A
6 3 B
7 3 C
8 4 A
What I need is to get all unique subsets of names ((A,B), (A,B,C), (A)) or exclude duplicate subsets. You can see that (A,B) is twice there, one for PARENT_ID=1 and one for 2.
I want to exclude such duplicates:
ID PARENT_ID NAME
1 1 A
2 1 B
5 3 A
6 3 B
7 3 C
8 4 A
You can use DISTINCT to only return different values.
e.g.
SELECT DISTINCT GROUP_CONCAT(NAME SEPARATOR ',') as subsets
FROM TABLE_1
GROUP BY PARENT_ID;
SQL Fiddle
I have used 'group_concat' assuming you are using 'Mysql'. The equivalent function in Oracle is 'listagg()'. you can see it in action here in SQL fiddle
Here is the solution:-
Select a.* from
test a
inner join
(
Select nm, min(parent_id) as p_id
from
(
Select Parent_id, group_concat(NAME) as nm
from test
group by Parent_ID
) a
group by nm
)b
on a.Parent_id=b.p_id
order by parent_id, name
I have a table 'TempC3'
Itemset itemset2
1 3
2 3
2 5
3 5
I want combination of elements in these columns without repetition. So the output table shall be
Itemset itemset2 Itemset3
1 3 5
2 3 5
1 2 3
I designed a query but it wont return the last row of the desired output table -
Select distinct a.Itemset,
a. Itemset2,
c.itemset2
from TempC3 a
Join TempC3 c
ON c.Itemset2 > a.Itemset2
This query only results this:
Itemset itemset2 Itemset3
1 3 5
2 3 5
Since you want all combinations of itemsets, you have to concatenate the two columns in your input table into a single column first. You could do this, for example, using a CTE:
Fiddle Here
WITH CTE AS (
SELECT Itemset FROM TempC3
UNION
SELECT Itemset2 FROM TempC3
)
SELECT I1.Itemset, I2.Itemset, I3.Itemset FROM CTE AS I1
INNER JOIN CTE AS I2 ON I2.Itemset > I1.Itemset
INNER JOIN CTE AS I3 ON I3.Itemset > I2.Itemset
I have sets of consecutive integers, organized by type, in table1. All values are between 1 and 10, inclusive.
table1:
row_id set_id type min_value max_value
1 1 a 1 3
2 2 a 4 10
3 3 a 6 10
4 4 a 2 5
5 5 b 1 9
6 6 c 1 7
7 7 c 3 10
8 8 d 1 2
9 9 d 3 3
10 10 d 4 5
11 11 d 7 10
In table2, within each type, I want to assemble all possible maximal, non-overlapping sets (though gaps that cannot be filled by any sets of the correct type are okay). Desired output:
table2:
row_id type group_id set_id
1 a 1 1
2 a 1 2
3 a 2 1
4 a 2 3
5 a 3 3
6 a 3 4
7 b 4 5
8 c 5 6
9 c 6 7
10 d 7 8
11 d 7 9
12 d 7 10
13 d 7 11
My current idea is to use the fact that there is a limited number of possible values. Steps:
Find all sets in table1 containing value 1. Copy them into table2.
Find all sets in table1 containing value 2 and not already in table2.
Join the sets from (2) with table1 on type, set_id, and having min_value greater than the group's greatest max_value.
For the sets from (2) that did not join in (3), insert them into table2. These start new groups that may be extended later.
Repeat steps (2) through (4) for values 3 through 10.
I think this will work, but it has a lot of pain-in-the-butt steps, especially for (2)--finding the sets not in table2, and (4)--finding the sets that did not join.
Do you know a faster, more efficient method? My real data has millions of sets, thousands of types, and hundreds of values (though fortunately, as in the example, the values are bounded), so scalability is essential.
I'm using PLSQL Developer with Oracle 10g (not 11g as I stated before--thanks, IT department). Thanks!
For Oracle 10g you can't use recursive CTEs, but with a bit of work you can do something similar with the connect by syntax. First you need to generate a CTE or in-line view which has all the non-overlapping links, which you can do with:
select t1.type, t1.set_id, t1.min_value, t1.max_value,
t2.set_id as next_set_id, t2.min_value as next_min_value,
t2.max_value as next_max_value,
row_number() over (order by t1.type, t1.set_id, t2.set_id) as group_id
from table1 t1
left join table1 t2 on t2.type = t1.type
and t2.min_value > t1.max_value
where not exists (
select 1
from table1 t4
where t4.type = t1.type
and t4.min_value > t1.max_value
and t4.max_value < t2.min_value
)
order by t1.type, group_id, t1.set_id, t2.set_id;
This took a bit of experimentation and it's certainly possible I've missed or lost something about the rules in the process; but that gives you 12 pseudo-rows, and is in my previous answer this allows the two separate chains starting with a/1 to be followed while constraining the d values to a single chain:
TYPE SET_ID MIN_VALUE MAX_VALUE NEXT_SET_ID NEXT_MIN_VALUE NEXT_MAX_VALUE GROUP_ID
---- ------ ---------- ---------- ----------- -------------- -------------- --------
a 1 1 3 2 4 10 1
a 1 1 3 3 6 10 2
a 2 4 10 3
a 3 6 10 4
a 4 2 5 3 6 10 5
b 5 1 9 6
c 6 1 7 7
c 7 3 10 8
d 8 1 2 9 3 3 9
d 9 3 3 10 4 5 10
d 10 4 5 11 7 10 11
d 11 7 10 12
And that can be used as a CTE; querying that with a connect-by loop:
with t as (
... -- same as above query
)
select t1.type,
dense_rank() over (partition by null
order by connect_by_root group_id) as group_id,
t1.set_id
from t t1
connect by type = prior type
and set_id = prior next_set_id
start with not exists (
select 1 from table1 t2
where t2.type = t1.type
and t2.max_value < t1.min_value
)
and not exists (
select 1 from t t3
where t3.type = t1.type
and t3.next_max_value < t1.next_min_value
)
order by t1.type, group_id, t1.min_value;
The dense_rank() makes the group IDs contiguous; not sure if you actually need those at all, or if their sequence matters, so it's optional really. connect_by_root gives the group ID for the start of the chain, so although there were 12 rows and 12 group_id values in the initial query, they don't all appear in the final result.
The connection is via two prior values, type and the next set ID found in the initial query. That creates all the chains, but own its own would also include shorter chains - for d you'd see 8,9,10,11 but also 9,10,11 and 10,11, which you don't want as separate groups. Those are eliminated by the start with conditions, which could maybe be simplified.
That gives:
TYPE GROUP_ID SET_ID
---- -------- ------
a 1 1
a 1 2
a 2 1
a 2 3
a 3 4
a 3 3
b 4 5
c 5 6
c 6 7
d 7 8
d 7 9
d 7 10
d 7 11
SQL Fiddle demo.
If you can identify all the groups and their starting set_id then you can use a recursive approach and do this all in a single statement, rather than needing to populate a table iteratively. However you'd need to benchmark both approaches both for speed/efficiency and resource consumption - whether it will scale for your data volumes and within your system's available resources would need to be verified.
If I understand when you decide to start a new group you can identify them all at once with a query like:
with t as (
select t1.type, t1.set_id, t1.min_value, t1.max_value,
t2.set_id as next_set_id, t2.min_value as next_min_value,
t2.max_value as next_max_value
from table1 t1
left join table1 t2 on t2.type = t1.type and t2.min_value > t1.max_value
where not exists (
select 1
from table1 t3
where t3.type = t1.type
and t3.max_value < t1.min_value
)
)
select t.type, t.set_id, t.min_value, t.max_value,
t.next_set_id, t.next_min_value, t.next_max_value,
row_number() over (order by t.type, t.min_value, t.next_min_value) as grp_id
from t
where not exists (
select 1 from t t2
where t2.type = t.type
and t2.next_max_value < t.next_min_value
)
order by grp_id;
The tricky bit here is getting all three groups for a, specifically the two groups that start with set_id = 1, but only one group for d. The inner select (in the CTE) looks for sets that don't have a lower non-overlapping range via the not exists clause, and outer-joins to the same table to get the next set(s) that don't overlap, which gives you two groups that start with set_id = 1, but also four that start with set_id = 9. The outer select then ignores everything but the lowest non-overlapping with a second not exists clause - but doesn't have to hit the real table again.
So that gives you:
TYPE SET_ID MIN_VALUE MAX_VALUE NEXT_SET_ID NEXT_MIN_VALUE NEXT_MAX_VALUE GRP_ID
---- ------ ---------- ---------- ----------- -------------- -------------- ------
a 1 1 3 2 4 10 1
a 1 1 3 3 6 10 2
a 4 2 5 3 6 10 3
b 5 1 9 4
c 6 1 7 5
c 7 3 10 6
d 8 1 2 9 3 3 7
You can then use that as the anchor member in a recursive subquery factoring clause:
with t as (
...
),
r (type, set_id, min_value, max_value,
next_set_id, next_min_value, next_max_value, grp_id) as (
select t.type, t.set_id, t.min_value, t.max_value,
t.next_set_id, t.next_min_value, t.next_max_value,
row_number() over (order by t.type, t.min_value, t.next_min_value)
from t
where not exists (
select 1 from t t2
where t2.type = t.type
and t2.next_max_value < t.next_min_value
)
...
If you left the r CTE with that and just did sleect * from r you'd get the same seven groups.
The recursive member then uses the next set_id and its range from that query as the next member of each group, and repeats the outer join/not-exists look up to find the next set(s) again; stopping when there is no next non-overlapping set:
...
union all
select r.type, r.next_set_id, r.next_min_value, r.next_max_value,
t.set_id, t.min_value, t.max_value, r.grp_id
from r
left join table1 t
on t.type = r.type
and t.min_value > r.next_max_value
and not exists (
select 1 from table1 t2
where t2.type = r.type
and t2.min_value > r.next_max_value
and t2.max_value < t.min_value
)
where r.next_set_id is not null -- to stop looking when you reach a leaf node
)
...
Finally you have a query based on the recursive CTE to get the columns you want and to specify the order:
...
select r.type, r.grp_id, r.set_id
from r
order by r.type, r.grp_id, r.min_value;
Which gets:
TYPE GRP_ID SET_ID
---- ---------- ----------
a 1 1
a 1 2
a 2 1
a 2 3
a 3 4
a 3 3
b 4 5
c 5 6
c 6 7
d 7 8
d 7 9
d 7 10
d 7 11
SQL Fiddle demo.
If you wanted to you could show the min/max values for each set, and could track and show the min/max value for each group. I've just show then columns from the question though.