So, I have this table:
id|otherid|key|value
--------------------
1 1 ak av
2 1 bk bv
3 2 ak av
3 2 ak av2
The things to note is that other ids are repeating and they can have same keys with values multiple times. The thing I want to retrieve would be the value for the key, or, if there are multiple values for same key some string.
So, I'd like to receive for otherids
otherid|key|value
-----------------
1 ak av
1 bk bv
2 ak SEQUENCE
Where 'SEQUENCE' string allows me to know that there are multiple values for the single key for otherid. What query would accomplish this?
To get one output row for multiple input rows, use grouping.
The count of rows in the group is available with COUNT(*); you can handle the cases with a CASE expression:
SELECT otherid,
key,
CASE COUNT(*)
WHEN 1 THEN MIN(value)
ELSE 'SEQUENCE'
END AS value
FROM MyTable
GROUP BY otherid,
key;
SELECT DISTINCT
otherid,key,
(SELECT
CASE
WHEN COUNT(value)=1 THEN value
WHEN COUNT(value)=0 THEN '*nil*'
ELSE '*sequence*'
END)
FROM datasingle
WHERE otherid=myid GROUP BY key;
Related
I need to get the next row from an ORDERBY query
I have 2 columns, ID(Primary key), Age(float) in a table T and I need something like the following
SELECT ID FROM T WHERE !> (inputted ID) + 1 rowID/Next row <! ORDERBY Age (then primary key, but I suspect if the Age values are the same SQLite would default to order by primary key anyway) LIMIT 1
Essentially it would select the next row after the inputted ID in the ordered table, its the next row / rowID + 1 I am not sure how to get.
As suggested here is a data set as an example
https://dbfiddle.uk?rdbms=sqlite_3.27&fiddle=19685ac20cc42041a59d318a01a2010f
ID Age
1 12.2
2 36.8
3 22.5
4 41
5 16.7
I am attempting to get the the following row from the ordered (by age) list given a specific ID
ID Age
1 12.2
5 16.7
3 22.5
2 36.8
4 41
Something similar to
SELECT ID FROM OrderedInfo WHERE ID = 5 ORDER BY Age ASC LIMIT 1 OFFSET 1;
My expected result would be '3' from the example data above
I have expanded the data set to include duplicate entries as I didn't implicitly state it could have such data - as such forpas answer works for the first example with no duplicate entries - thanks for your help
https://dbfiddle.uk?rdbms=sqlite_3.27&fiddle=f13d7f5a44ba414784547d9bbdf4997e
Use a subquery for the ID that you want in the WHERE clause:
SELECT *
FROM OrderedInfo
WHERE Age > (SELECT Age FROM OrderedInfo WHERE ID = 5)
ORDER BY Age LIMIT 1;
See the demo.
If there are duplicate values in the column Age use a CTE that returns the row that you want and join it to the table so that you expand the conditions:
WITH cte AS (SELECT ID, Age FROM OrderedInfo WHERE ID = 5)
SELECT o.*
FROM OrderedInfo o INNER JOIN cte c
ON o.Age > c.Age OR (o.Age = c.Age AND o.ID > c.ID)
ORDER BY o.Age, o.ID LIMIT 1;
See the demo.
I have the query
select d.did, count ( h.did ), unique_interested
from dealer as d
left outer join house as h
on h.did = d.did
left outer join (
-- cid = customer id
select hid, count (cid) as unique_interested
from is_interested
group by hid
) as ok
on h.hid = ok.hid
group by d.did
order by d.did asc
;
which is supposed to select the number of houses that each dealer is dealing, and the number of unique customers interested in said houses (as in the number of customers per dealer). This should happen even if the dealers have no houses to deal at the moment, which is why I'm using left outer joins when constructing the table the columns will be picked from.
Now, running this query against my database produces the following output:
d.did count ( h.did) unique_interested
----- -------------- ----------------
1 3
2 3 1
3 0
As you can see, instead of printing 0 in the last column, count returns null, when there is a null in one of the aparments produced by the last part of the join (as in cid is null):
select hid, count ( cid ) as unique_interested
from is_interested
group by hid
I know this is because there are apartments in the table produced by from, that no-one is interested in. But shouldn't count produce 0 instead of the actual column value null in every case?
Any explanation as to why this is happening would be appreciated, as it would lead me towards an answer to another question, which is "Why am I not getting the right number of unique interested customers per dealer from the table is_interested?", as with the current state of my database, the output should look more like:
d.did count ( h.did) unique_interested
----- -------------- ----------------
1 3 2
2 3 2
3 0 0
The NTH function is really useful for extracting nested array elements in BQ, but its utility for a given table depends on each row's nested array containing the same amount of elements, and in the same order. If I have a 2+ column nested array where one column is variable name/ID, and the different instances of the array in different rows have inconsistent naming and/or ordering, is there an elegant way to fetch/pivot a variable based on the variable name/ID?
For example, if row1 has customDimensions array:
index value
4 aaa
23 bbb
70 ccc
and row2 has customDimensions array:
index value
4 ddd
70 eee
I'd want to run something like
SELECT
NTHLOOKUP(70, customdims.index, customdims.value) as val70,
NTHLOOKUP(4, customdims.index, customdims.value) as val4,
NTHLOOKUP(23, customdims.index, customdims.value) as val23
from my_table;
And get:
val70 val4 val23
ccc aaa bbb
eee ddd (null)
I've been able to get this sort of result by making a subquery for each desired index value, unnesting the array in each and filtering WHERE index = (value), but that gets really ugly as the variables pile up. Is there an alternative?
EDIT: Based on Mikhail's answer below (thank you!!) I was able to write my query more elegantly. Not quite as slick as an NTHLOOKUP, but I'll take it:
select id,
max(case when index = 41 then value[OFFSET(0)] else '' end) as val41,
max(case when index = 59 then value[OFFSET(0)] else '' end) as val59
from
(select
concat(array1.thing1, array1.thing2) as id,
cd.index,
ARRAY_AGG(distinct cd.value) as value
FROM my_table g
,unnest(array1) as array1
,unnest(array1.customDimensions) as cd
where index in (41,59)
group by 1,2
order by 1,2
) x
group by 1
order by 1
The best I can "offer" is below (BigQuery Standard SQL)
#standardSQL
WITH `project.dataset.my_table` AS (
SELECT ARRAY<STRUCT<index INT64, value STRING>>
[(4, 'aaa'), (23, 'bbb'), (70, 'ccc')] customDimensions
UNION ALL
SELECT ARRAY<STRUCT<index INT64, value STRING>>
[(4, 'ddd'), (70, 'eee')] customDimensions
)
SELECT cd.index, ARRAY_AGG(cd.value) VALUES
FROM `project.dataset.my_table`,
UNNEST(customDimensions) cd
GROUP BY cd.index
with result as below
Row index values
1 4 aaa
ddd
2 23 bbb
3 70 ccc
eee
I would recommend to stay with this flatten version as it serves most of practical cases I can think of
But if you still want to further pivot this - there are quite a number of posts related to how to pivot in BigQuery
I've been able to get this sort of result by making a subquery for each desired index value, unnesting the array in each and filtering WHERE index = (value), but that gets really ugly as the variables pile up. Is there an alternative?
Yes, you can use a user-defined function to encapsulate the common logic. For example,
CREATE TEMP FUNCTION NTHLOOKUP(
targetIndex INT64,
customDimensions ARRAY<STRUCT<index INT64, value STRING>>
) AS (
(SELECT value FROM UNNEST(customDimensions)
WHERE index = targetIndex)
);
SELECT
NTHLOOKUP(70, customDimensions) as val70,
NTHLOOKUP(4, customDimensions) as val4,
NTHLOOKUP(23, customDimensions) as val23
from my_table;
I have a query in Teradata. I want to add an additional column that would be a VARCHAR.
It should say whether the selected record is even or odd
select id, name, CASE newColumn WHEN --- ???
from my table
Like this
id name newColumn
1 asdf odd
2 ts df even
32 htssdf odd
4 asdfsd even
23 gftht odd
How can I do this
Based on your example, I can't tell how you are sorting the results. You would need to define a sort order. Let's assume you would do it based on the id number.
SELECT id, name,
ROW_NUMBER() OVER(ORDER BY id) row_id,
CASE WHEN ROW_NUMBER() OVER(ORDER BY id) MOD 2 = 0 THEN 'Even' ELSE 'Odd' END newColumn
FROM my table
The row_id is incrementally assigned based on the id field being sorted ascending. You then use the MOD function to determine if there's a remainder after dividing the number by a value (in this case 2). Result would look like the following:
id name row_id newColumn
1 asdf 1 Odd
2 ts df 2 Even
4 asdfsd 3 Odd
23 gftht 4 Even
32 htssdf 5 Odd
I don't know if I'm being dumb here but I can't seem to find an efficient way to do this. I wrote a very long and inefficient query that does what I need, but what I WANT is a more efficient way.
I have 2 result sets that displays an ID (a PK which is generic/from the same source in both sets) and a FLAG (A - approve and V - Validate).
Result Set 1
ID FLAG
1 V
2 V
3 V
4 V
5 V
6 V
Result Set 2
ID FLAG
2 A
5 A
7 A
8 A
I want to "merge" these two sets to give me this output:
ID FLAG
1 V
2 (V/A)
3 V
4 V
5 (V/A)
6 V
7 A
8 A
Neither of the 2 result sets will at any time have all the ID's to make a simple left join with a case statement on the other result set an easy solution.
I'm currently doing a union between the two sets to get ALL the ID's. Thereafter I left join the 2 result sets to get the required '(V/A)' by use of a case statement.
There must be a more efficient way but I just can't seem to figure it out now as I'm running low on amps... I need a holiday... :-/
Thanks in advance!
Use a FULL OUTER JOIN:
SELECT ID,
CASE
WHEN t1.FLAG IS NULL THEN t2.FLAG
WHEN t2.FLAG IS NULL THEN t1.FLAG
ELSE '(' || t1.FLAG || '/' || t2.FLAG || ')'
END AS MERGED_FLAG
FROM TABLE1 t1
FULL OUTER JOIN TABLE2 t2
USING (ID)
ORDER BY ID
See this SQLFiddle.
Share and enjoy.
I think that you can use xmlagg. Here an exemple :
SELECT deptno,
SUBSTR (REPLACE (REPLACE (XMLAGG (XMLELEMENT ("x", ename)
ORDER BY ename),'</x>'),'<x>','|'),2) as concated_list
FROM emp
GROUP BY deptno
ORDER BY deptno;
Bye