select m.value
from MY_TABLE m
where m.value in (select m2.some_third_value, m2.some_fourth_value
from MY_TABLE_2 m2
where m2.first_val member of v_my_array
or m2.second_val member of v_my_array_2)
Is it possible to write a select similar to this, where m.value is compared to two columns and has to match at least one of those? Something like where m.value in (select m2.first_val, m2.second_val). Or is writing two separate selects unavoidable here?
No. When there are multiple columns in the IN clause, there must be the same number of columns in the WHERE clause. The pairwise query compares each record in the WHERE clause against the records returned by the sub-query. The statement below
SELECT *
FROM table_main m
WHERE ( m.col_1, m.col_2 ) IN (SELECT s.col_a,
s.col_b
FROM table_sub s)
is equivalent to
SELECT *
FROM table_main m
WHERE EXISTS (SELECT 1
FROM table_sub s
WHERE m.col_1 = s.col_a
AND m.col_2 = s.col_b)
The only way to search both columns in one SELECT statement would be to OUTER JOIN the second table to the first table.
SELECT m.*
FROM table_main m
LEFT JOIN table_sub s ON (m.col_1 = s.col_a OR m.col_1 = s.col_b)
WHERE m.col_1 = s.col_a
OR m.col_1 = s.col_b
Related
I'm trying to update a table with to many rows 388.000.
This is the query:
update DL_RG_ANALYTICS.SH_historico
from
(
SELECT
CAST((MAX_DIA - DIA_PAGO) AS INTEGER) AS DIAS_AL_CIERRE_1
FROM
(SELECT * FROM DL_RG_ANALYTICS.SH_historico A
LEFT JOIN
(SELECT ANO||MES AS ANO_MES, MAX(DIA) AS MAX_DIA FROM DL_RG_ANALYTICS.SH_CALENDARIO
GROUP BY 1) B
ON A.ANOMES = B.ANO_MES
) M) N
SET DIAS_AL_CIERRE = DIAS_AL_CIERRE_1;
Any help is apreciate.
This first thing I'd do is replace the SELECT * with only the columns you need. You can also remove the M derived table to make it easier to read:
UPDATE DL_RG_ANALYTICS.SH_historico
FROM (
SELECT CAST((MAX_DIA - DIA_PAGO) AS INTEGER) AS DIAS_AL_CIERRE_1
FROM DL_RG_ANALYTICS.SH_historico A
LEFT JOIN (
SELECT ANO || MES AS ANO_MES, MAX(DIA) AS MAX_DIA
FROM DL_RG_ANALYTICS.SH_CALENDARIO
GROUP BY 1
) B ON A.ANOMES = B.ANO_MES
) N
SET DIAS_AL_CIERRE = DIAS_AL_CIERRE_1;
What indexes are defined on the SH_CALENDARIO table? If there is a composite index of (ANO, MES) then you should re-write your LEFT JOIN sub-query to GROUP BY these two columns since you concatenate them together anyways. In general, you want to perform joins, GROUP BY and OLAP functions on indexes, so there will be less row re-distribution and they will run more efficiently.
Also, this query is updating all rows in the table with the same value. Is this intended, or do you want to include extra columns in your WHERE clause?
I'm performing an Sqlite3 query similar to
SELECT * FROM nodes WHERE name IN ('name1', 'name2', 'name3', ...) LIMIT 1
Am I guaranteed that it will search for name1 first, name2 second, etc? Such that by limiting my output to 1 I know that I found the first hit according to my ordering of items in the IN clause?
Update: with some testing it seems to always return the first hit in the index regardless of the IN order. It's using the order of the index on name. Is there some way to enforce the search order?
The order of the returned rows is not guaranteed to match the order of the items inside the parenthesis after IN.
What you can do is use ORDER BY in your statement with the use of the function INSTR():
SELECT * FROM nodes
WHERE name IN ('name1', 'name2', 'name3')
ORDER BY INSTR(',name1,name2,name3,', ',' || name || ',')
LIMIT 1
This code uses the same list from the IN clause as a string, where the items are in the same order, concatenated and separated by commas, assuming that the items do not contain commas.
This way the results are ordered by their position in the list and then LIMIT 1 will return the 1st of them which is closer to the start of the list.
Another way to achieve the same results is by using a CTE which returns the list along with an Id which serves as the desired ordering of the results, which will be joined to the table:
WITH list(id, item) AS (
SELECT 1, 'name1' UNION ALL
SELECT 2, 'name2' UNION ALL
SELECT 3, 'name3'
)
SELECT n.*
FROM nodes n INNER JOIN list l
ON l.item = n.name
ORDER BY l.id
LIMIT 1
Or:
WITH list(id, item) AS (
SELECT * FROM (VALUES
(1, 'name1'), (2, 'name2'), (3, 'name3')
)
)
SELECT n.*
FROM nodes n INNER JOIN list l
ON l.item = n.name
ORDER BY l.id
LIMIT 1
This way you don't have to repeat the list twice.
I'm trying to replace a placeholder string inside a selection of 10 random records with a random string (a name) taken from another table, using only sqlite statements.
i've done a subquery in order to replace() of the placeholder with the results of a subquery. I thought that each subquery loaded a random name from the names table, but i've found that it's not the case and each placeholder is replaced with the same string.
select id, (replace (snippet, "%NAME%", (select
name from names
where gender = "male"
) )
) as snippet
from imagedata
where timestamp is not NULL
order by random()
limit 10
I was expecting for each row of the SELECT to have different random replacement every time the subquery is invoked.
hello i'm %NAME% and this is my house
This is the car of %NAME%, let me know what you think
instead each row has the same kind of replacement:
hello i'm david and this is my house
This is the car of david, let me know what you think
and so on...
I'm not sure it can be done inside sqlite or if i have to do it in php over two different database queries.
Thanks in advance!
Seems that random() in the subquery is only evaluated once.
Try this:
select
i.id,
replace(i.snippet, '%NAME%', n.name) snippet
from (
select
id,
snippet,
abs(random()) % (select count(*) from names where gender = 'male') + 1 num
from imagedata
where timestamp is not NULL
order by random() limit 10
) i inner join (
select
n.name,
(select count(*) from names where name < n.name and gender = 'male') + 1 num
from names n
where gender = 'male'
) n on n.num = i.num
I need to select data from four tables based on only one.
In my 'calculated' table, I have all the records I need.
But I need to retrieve some other info for each record, from 'programs', 'term' and 'imported' tables.
'calculated' has ID from 'programs'.
But, to achieve a record from 'imported', I need to join the 'item' table, because 'item' has ID from 'programs' and from 'imported'.
'term' has ID from 'imported'.
So, I tried this:
select c.date,
p.name,
c.name1,
c.name2,
t.date,
i.version,
c.price1,
c.price2,
c.price3
from calculated c, programs p, term t, imported i, item it
where c.programs_id = p.programs_id
and c.programs_id = it.programs_id
and it.imported_id = i.imported_id
and i.term_id = t.term_id;
But when I use count(*) on 'calculated', I get 30k of records, and from my select statement I get more than 130 millions of records.
What am I doing wrong?
What should I do for this to work?
If all duplicates rows are equivalent, u can try smth like this
select c.date,
p.name,
c.name1,
c.name2,
t.date,
i.version,
c.price1,
c.price2,
c.price3
from calculated c, programs p, term t, imported i
where c.programs_id = p.programs_id and
(select imported_id from item it where c.programs_id = it.programs_id and rownum = 1) = i.imported_id
and i.term_id = t.term_id;
where "rownum = 1" is restriction on the selection of one line for oracle.
you forgot to join term table.
Probably you need to add
and t.term_id = i.term_id
I have this query
Select distinct p_id, p_date,p_city
from p_master
where p_a_id in(1,2,5,8,2,1,10,02)
and my IN clause contains 200 values. How do I get to know which ones weren't returned by the query. Each value in the IN clause may have a record in some cases they don't. I want to know all the records that weren't found for any selected p_a_id type.
Please help
This will do the trick but I'm sure there's an easier way to find this out :-)
with test1 as
(select '1,2,5,8,2,1,10,02' str from dual)
select * from (
select trim(x.column_value.extract('e/text()')) cols
from test1 t, table (xmlsequence(xmltype('<e><e>' || replace(t.str,',','</e><e>')|| '</e></e>').extract('e/e'))) x) cols
left outer join
(Select count(*), p_a_id from p_master where p_a_id in (1,2,5,8,2,1,10,02) group by p_a_id) p
on p.p_a_id = cols.cols
where p_a_id is null
;