I need to add the third column to the first column (my desire is that the first column will include also the third column)
Current status:
Desired Results:
You want UNION ALL :
SELECT t.entity, t.activity
FROM table t
UNION ALL
SELECT t.entity2, t.activity2
FROM table t;
If you have a lot of data, you may not want to scan the table multiple times -- which is what union all does.
Instead:
select (case when n.n = 1 then entity
when n.n = 2 then entity_2
end) as entity,
(case when n.n = 1 then activity
when n.n = 2 then activity_2
end) as activity
from t cross join
(select 1 as n from dual union all
select 2 as n from dual
) n;
In Oracle 12C+, this is simplified using lateral joins:
select t.entity, s.activity
from t cross join lateral
(select t.entity, t.activity from dual union all
select t.entity_2, t.activity_2 from dual
) s;
select entity, activity from <table>
union all
select entity_2, activity_2 from <table>
in general:
select col1,col2 from table1
union all
select col3,col4 form table1;
Related
I have a query with union all functionality each giving me count(*) return from respective queries and another count query like below. I want an outer query that gives the total.
1st query
select count(*) from a
union all
select count(*) from b;
Sample result for 1st query:
COUNT
10
40
2nd query
select count(*) from xy;
Sample result for 2nd query:
COUNT
20
I want output like this in 2 rows:
TABLES
COUNT
xy
20
ab
50
something like above. How can I achieve this in oracle? please suggest the best way to do this.
I wrote a select and union all but not sure how to proceed further.
One option is to sum counts returned by the 1st query and then union it with the 2nd; also, add constants which show the source:
select 'ab' what, (select count(*) from a) + (select count(*) from b) cnt from dual
union all
select 'xy', count(*) from xy;
You can use:
SELECT 'ab' AS type,
COUNT(*) AS total
FROM ( SELECT 1 FROM a UNION ALL
SELECT 1 from b );
UNION ALL
SELECT 'xy', COUNT(*)
FROM xy;
You can sum counts from your three unioned Select statements and group the result by combination of sources:
WITH
a AS
( Select LEVEL "A_ID", 'some column a' "COL_A" From Dual Connect By LEVEL <= 30 ),
b AS
( Select LEVEL "B_ID", 'some column b' "COL_B" From Dual Connect By LEVEL <= 20 ),
xy AS
( Select LEVEL "XY_ID", 'some column xy' "COL_XY" From Dual Connect By LEVEL <= 20 )
with above sample data it is like here:
SELECT
CASE WHEN SOURCE IN('a', 'b') THEN 'ab' ELSE SOURCE END "SOURCE",
Sum(CNT) "CNT"
FROM
( Select 'a' "SOURCE", Count(*) "CNT" From a Union All
Select 'b', Count(*) From b Union All
Select 'xy', Count(*) From xy
)
GROUP BY
CASE WHEN SOURCE IN('a', 'b') THEN 'ab' ELSE SOURCE END
--
-- R e s u l t :
-- SOURCE CNT
-- ------ ----------
-- ab 50
-- xy 20
Assuming that your real queries can be a lot more complex, I take it as a given that we shall not try to change them and somehow merge or split them.
Your first query returns two rows. You want to get their sum, so you must aggregate the result and use SUM.
Below query uses CTEs (subqueries in the WITH clause) for your two queries, and then a query that gets this sum. It then uses these CTEs for the final UNION ALL query.
with query1 (cnt) as (select count(*) from a union all select count(*) from b)
, query2 (cnt) as (select count(*) from xy)
, sumquery1 (total) as (select sum(cnt) from query1)
select 'ab' as tables, total from sumquery1
union all
select 'xy' as tables, cnt from query2
order by tables desc;
Is there a "better" way to refactor the query below that returns the number occurrences of a particular value (e.g. 'A') for each distinct id? The challenge seems to be keeping id = 2 in the result set even though the count is zero (id = 2 is never related to 'A'). It has a common table expression, NVL function, in-line view, distinct, and left join. Is all of that really needed to get this job done? (Oracle 19c)
create table T (id, val) as
select 1, 'A' from dual
union all select 1, 'B' from dual
union all select 1, 'A' from dual
union all select 2, 'B' from dual
union all select 2, 'B' from dual
union all select 3, 'A' from dual
;
with C as (select id, val, count(*) cnt from T where val = 'A' group by id, val)
select D.id, nvl(C.cnt, 0) cnt_with_zero from (select distinct id from T) D left join C on D.id = C.id
order by id
;
ID CNT_WITH_ZERO
---------- -------------
1 2
2 0
3 1
A simple way is conditional aggregation:
select id,
sum(case when val = 'A' then 1 else 0 end) as num_As
from t
group by id;
If you have another table with one row per id, you I would recommend:
select i.id,
(select count(*) from t where t.id = i.id and t.val = 'A') as num_As
from ids i;
I'm currently writing code in SQL to add the column in red to the following table:
The logic is the following:
For every row:
if flag for this row =1 then use date of this row
if flag for this row =0 then find the latest row (based on date) on which flag was = 1 for the same party and return the date of that row. If no such row exists, return null
I've found a way to do this by joining the table to itself but I would like to avoid doing that as the size of the table is pretty massive.
What I have
select b.*, a.date,
from table a left join table b on a.party=b.party
where a.flag =1
Someone told me I could use the lag function, the partition over function and a case when to return the value I'm after but I haven't been able to figure it out.
Can someone help? Thank you so much!
try this
DECLARE #tab1 TABLE(PARTY CHAR(1),DATE DATE,Flag bit)
INSERT INTO #tab1
SELECT 'A','7-24-2018',1 Union ALL
SELECT 'A','7-28-2018',0 Union ALL
SELECT 'A','7-29-2018',0 Union ALL
SELECT 'A','7-29-2018',0 Union ALL
SELECT 'B','7-13-2018',1 Union ALL
SELECT 'B','7-17-2018',0 Union ALL
SELECT 'B','7-18-2018',0 Union ALL
SELECT 'C','7-8-2018',1 Union ALL
SELECT 'C','7-13-2018',0 Union ALL
SELECT 'C','7-19-2018',0 Union ALL
SELECT 'C','7-19-2018',0 Union ALL
SELECT 'C','7-20-2018',0
select t.*,
max(case when flag = 1 then date end) over (partition by PARTY order by date) as [Last Flag On Date]
from #tab1 t
try this :->
select b.*, a.date, from table a left join table b on a.party=b.party where a.flag = CASE WHEN a.flag = 1 THEN a.date WHEN a.flag = 0 THEN ( SELECT date FROM ( SELECT TOP 1 row_number() OVER ( ORDER BY a.date DESC ) rs , a.date FROM a WHERE a.flag = 1 GROUP BY a.date) s ) END
use CROSS APPLY() to obtain the latest row with flag 1
SELECT *
FROM yourtable t
CROSS APPLY
(
SELECT TOP 1 x.Date as [Last flag on date]
FROM yourtable x
WHERE x.Party = t.Party
AND x.Flag = 1
ORDER BY x.Date desc
) d
Yes it can be done by joining table, if written properly.
#Sahi query is also good and simple.
Since you were asking for Dynamic LAG()
This query may or may not be very performant,but it certainly worth learning.
Test this with various sample data and tell me for which scenario it do not work.
So that I correct my script accordingly.
DECLARE #tab1 TABLE(PARTY CHAR(1),DATE DATE,Flag bit)
INSERT INTO #tab1
SELECT 'A','7-24-2018',1 Union ALL
SELECT 'A','7-28-2018',0 Union ALL
SELECT 'A','7-29-2018',0 Union ALL
SELECT 'A','7-29-2018',0 Union ALL
SELECT 'B','7-13-2018',1 Union ALL
SELECT 'B','7-17-2018',0 Union ALL
SELECT 'B','7-18-2018',0 Union ALL
SELECT 'C','7-8-2018',1 Union ALL
SELECT 'C','7-13-2018',0 Union ALL
SELECT 'C','7-19-2018',0 Union ALL
SELECT 'C','7-19-2018',0 Union ALL
SELECT 'C','7-20-2018',0;
WITH cte
AS (SELECT *,
Row_number()
OVER (
partition BY party
ORDER BY flag DESC, [date] DESC ) rn
FROM #tab1)
SELECT *,
CASE
WHEN flag = 1 THEN [date]
ELSE Lag([date], (SELECT TOP 1 a.rn - a1.rn
FROM cte a1
WHERE a1.party = a.party))
OVER (
ORDER BY party )
END
FROM cte a
As the title says, I'm trying to add an extra column to a table which autoincrements everytime a different string in another column changes.
I would like to do this in a query.
Example:
MyCol GroupID
Cable 1
Cable 1
Foo 2
Foo 2
Foo 2
Fuzz 3
Fizz 4
Tv 5
Tv 5
The GroupID column is what I want to accomplish.
We can be sure that MyCol's strings will be the same in each subgroup (Foo will always be Foo, etc).
Thanks in advance
If I understand correctly, you can use dense_rank():
select t.*, dense_rank() over (order by col1) as groupid
from t;
You could make a temporal table with the distinct value of the MyCol and get the groupId throught the RowNumber of the temp table, and join the rownumbered result with your table.
This is a raw example in oracle:
WITH data AS
(SELECT 'Cable' MyCol FROM dual
UNION ALL
SELECT 'Cable' FROM dual
UNION ALL
SELECT 'Foo' FROM dual
UNION ALL
SELECT 'Foo' FROM dual
UNION ALL
SELECT 'Foo' FROM dual
UNION ALL
SELECT 'Fuzz' FROM dual
UNION ALL
SELECT 'Fizz' FROM dual
UNION ALL
SELECT 'Tv' FROM dual
UNION ALL
SELECT 'Tv' FROM dual
),
tablename AS
(SELECT * FROM data
),
temp AS
( SELECT DISTINCT mycol FROM tablename
),
temp2 AS
( SELECT mycol, rownum AS groupid from temp
)
SELECT tablename.mycol, temp2.groupid FROM temp2 JOIN tablename ON temp2.mycol = tablename.mycol
You could also check for a way to implement the tabibitosan method knowing that your column condition is string.
I have a quick question about a select statement condition.
I have the following table with the following items. What I need to get is the object id that matches both type id's.
TypeId ObjectId
1 10
2 10
1 11
So I need to get both object 10 because it matches type id 1 and 2.
SELECT ObjectId
FROM Table
WHERE TypeId = 1
AND TypeId = 2
Obviously this doesn't work because it won't match both conditions for the same row. How do I perform this query?
Also note that I may pass in 2 or more type id's to narrow down the results.
Self-join:
SELECT t1.ObjectId
FROM Table AS t1
INNER JOIN Table AS t2
ON t1.ObjectId = t2.ObjectId
AND t1.TypeId = 1
AND t2.TypeId = 2
Note sure how you want the behavior to work when passing in values, but that's a start.
I upvoted the answer from #Cade Roux, and that's how I would do it.
But FWIW, here's an alternative solution:
SELECT ObjectId
FROM Table
WHERE TypeId IN (1, 2)
GROUP BY ObjectId
HAVING COUNT(*) = 2;
Assuming uniqueness over TypeId, ObjectId.
Re the comment from #Josh that he may need to search for three or more TypeId values:
The solution using JOIN requires a join per value you're searching for. The solution above using GROUP BY may be easier if you find yourself searching for an increasing number of values.
This code is written with Oracle in mind. It should be general enough for other flavors of SQL
select t1.ObjectId from Table t1
join Table t2 on t2.TypeId = 2 and t1.ObjectId = t2.ObjectId
where t1.TypeId = 1;
To add additional TypeIds, you just have to add another join:
select t1.ObjectId from Table t1
join Table t2 on t2.TypeId = 2 and t1.ObjectId = t2.ObjectId
join Table t3 on t3.TypeId = 3 and t1.ObjectId = t3.ObjectId
join Table t4 on t4.TypeId = 4 and t1.ObjectId = t4.ObjectId
where t1.TypeId = 1;
Important note: as you add more joins, performance will suffer a LOT.
In regards to Bill's answer you can change it to the following to get rid of the need to assume uniqueness:
SELECT ObjectId
FROM (SELECT distinct ObjectId, TypeId from Table)
WHERE TypeId IN (1, 2)
GROUP BY ObjectId
HAVING COUNT(*) = 2;
His way of doing it scales better as the number of types gets larger.
Try this
Sample Input:(Case 1)
declare #t table(Typeid int,ObjectId int)
insert into #t
select 1,10 union all select 2,10 union all
select 1,11
select * from #t
Sample Input:(Case 2)
declare #t table(Typeid int,ObjectId int)
insert into #t
select 1,10 union all select 2,10 union all
select 3,10 union all select 4,10 union all
select 5,10 union all select 6,10 union all
select 1,11 union all select 2,11 union all
select 3,11 union all select 4,11 union all
select 5,11 union all select 1,12 union all
select 2,12 union all select 3,12 union all
select 4,12 union all select 5,12 union all
select 6,12
select * from #t
Sample Input:(Case 3)[Duplicate entries are there]
declare #t table(Typeid int,ObjectId int)
insert into #t
select 1,10 union all select 2,10 union all
select 1,10 union all select 2,10 union all
select 3,10 union all select 4,10 union all
select 5,10 union all select 6,10 union all
select 1,11 union all select 2,11 union all
select 3,11 union all select 4,11 union all
select 5,11 union all select 1,12 union all
select 2,12 union all select 3,12 union all
select 4,12 union all select 5,12 union all
select 6,12 union all select 3,12
For case 1, the output should be 10
For case 2 & 3, the output should be 10 and 12
Query:
select X.ObjectId from
(
select
T.ObjectId
,count(ObjectId) cnt
from(select distinct ObjectId,Typeid from #t)T
where T.Typeid in(select Typeid from #t)
group by T.ObjectId )X
join (select max(Typeid) maxcnt from #t)Y
on X.cnt = Y.maxcnt