I have the following query:
SELECT
title,
(stock_one + stock_two) AS global_stock
FROM
product
ORDER BY
global_stock = 0,
title;
Running it in PostgreSQL 8.1.23 i get this error:
Query failed: ERROR: column "global_stock" does not exist
Anybody can help me to put it to work? I need the availale items first, after them the unnavailable items. Many thanks!
You can always ORDER BY this way:
select
title,
( stock_one + stock_two ) as global_stock
from product
order by 2, 1
or wrap it in another SELECT:
SELECT *
from
(
select
title,
( stock_one + stock_two ) as global_stock
from product
) x
order by (case when global_stock = 0 then 1 else 0 end) desc, title
One solution is to use the position:
select title,
( stock_one + stock_two ) as global_stock
from product
order by 2, 1
However, the alias should work, but not necessarily the expression. What do you mean by "global_stock = 0"? Do you mean the following:
select title,
( stock_one + stock_two ) as global_stock
from product
order by (case when global_stock = 0 then 1 else 0 end) desc, title
In case anyone finds this when googling for whether you can just ORDER BY my_alias: Yes, you can. This cost me a couple hours.
As the postgres docs state:
The ordinal number refers to the ordinal (left-to-right) position of the output column. This feature makes it possible to define an ordering on the basis of a column that does not have a unique name. This is never absolutely necessary because it is always possible to assign a name to an output column using the AS clause.
So either this has been fixed since, or this question is specifically about the ORDER BY my_alias = 0, other_column syntax which I didn't actually need.
Related
I am trying to use COUNT(DISTINC column) OVER(PARTITION BY column) when I am using COUNT + window function(OVER).
I get an error like the one in the title and can't get it to work.
I have looked into how to deal with this error, but I have not found an example of how to deal with such a complex query as the one below.
I cannot find an example of how to deal with such a complex query as shown below, and I am not sure how to handle it.
The COUNT part of the problem exists on line 65.
How can such a complex query be resolved without slowing down?
WITH RECURSIVE "cte" AS((
SELECT
"videos_productvideocomment"."id",
"videos_productvideocomment"."user_id",
"videos_productvideocomment"."video_id",
"videos_productvideocomment"."parent_id",
"videos_productvideocomment"."text",
"videos_productvideocomment"."commented_at",
"videos_productvideocomment"."edited_at",
"videos_productvideocomment"."created_at",
"videos_productvideocomment"."updated_at",
"videos_productvideocomment"."id" AS "root_id"
FROM
"videos_productvideocomment"
WHERE
(
"videos_productvideocomment"."parent_id" IS NULL
AND "videos_productvideocomment"."video_id" = 'f264433c-c0af-49cc-8b40-84453da71b2d'
)
) UNION(
SELECT
"videos_productvideocomment"."id",
"videos_productvideocomment"."user_id",
"videos_productvideocomment"."video_id",
"videos_productvideocomment"."parent_id",
"videos_productvideocomment"."text",
"videos_productvideocomment"."commented_at",
"videos_productvideocomment"."edited_at",
"videos_productvideocomment"."created_at",
"videos_productvideocomment"."updated_at",
"cte"."root_id" AS "root_id"
FROM
"videos_productvideocomment"
INNER JOIN
"cte"
ON "videos_productvideocomment"."parent_id" = "cte"."id"
))
SELECT
*,
EXISTS(
SELECT
(1) AS "a"
FROM
"videos_productvideolikecomment" U0
WHERE
(
U0."comment_id" = t."id"
AND U0."user_id" = '3bd3bc86-0335-481e-9fd2-eb2fb1168f48'
)
LIMIT 1
) AS "liked"
FROM
(
SELECT DISTINCT
"cte"."id",
"cte"."created_at",
"cte"."updated_at",
"cte"."user_id",
"cte"."text",
"cte"."commented_at",
"cte"."edited_at",
"cte"."parent_id",
"cte"."video_id",
"cte"."root_id" AS "root_id",
COUNT(DISTINCT "cte"."root_id") OVER(PARTITION BY "cte"."root_id") AS "reply_count", <--- here
COUNT("videos_productvideolikecomment"."id") OVER(PARTITION BY "cte"."id") AS "liked_count"
FROM
"cte"
LEFT OUTER JOIN
"videos_productvideolikecomment"
ON (
"cte"."id" = "videos_productvideolikecomment"."comment_id"
)
) t
WHERE
t."id" = t."root_id"
ORDER BY
CASE
WHEN t."user_id" = '3bd3bc86-0335-481e-9fd2-eb2fb1168f48' THEN 0
ELSE 1
END ASC,
"liked_count" DESC
DISTINCT will look for duplicates and remove it, but in big data it will take a lot of time to process this query, you should process the middle of the record in the programming part I think it will be fast than. Thank
Error Message :
select list expression not produced by aggregation output (missing
from GROUP BY clause?): CASE WHEN (flag = 1) THEN date_add(lead_ctxdt,
-1) ELSE ctx_date END lot_endt
code :
select c.enrolid, c.ctx_date, c.ctx_regimen, c.lead_ctx, c.lead_ctxdt, min(c.ctx_date) as lot_stdt,
case when (flag = 1 ) then date_add(lead_ctxdt, -1)
else ctx_date
end as lot_endt
from
(
select p.*,
case when (ctx_regimen <> lead_ctx) then 1
else 0
end as flag
from
(
select a.*, lead(a.ctx_regimen, 1) over(partition by enrolid order by ctx_date) as lead_ctx,
lead(ctx_date, 1) over (partition by enrolid order by ctx_date) as lead_ctxdt
from
(
select enrolid, ctx_date, group_concat(distinct ctx_codes) as ctx_regimen
from lotinfo
where ctx_date between ctx_date and date_add(ctx_date, 5)
group by enrolid, ctx_date
) as a
) as p
) as c
group by c.enrolid, c.ctx_date, c.ctx_regimen, c.lead_ctx, c.lead_ctxdt
I want to get the lead_ctx date minus one as the date when the flag is 1
So i found the answer by executing a couple of times the minor changes. Let me tell you, that when you are trying to min or max alongside you have group_conact in the same query then in Impala this doesn't work. You have to write it in two queries per one more sub query and the min() of something in the outer query or vice versa.
Thank you #dnoeth for letting me understand I have the answer with me already.
I need to create some kind of a uniform query for multiple tables. Some tables contain a certain column with a type. If this is the case, I need to apply filtering to it. I don't know how to do this.
I have for example two tables
table_customer_1
CustomerId, CustomerType
1, 1
2, 1
3, 2
Table_customer_2
Customerid
4
5
6
The query needs to be something like the one below and should work for both tables (the table name wil be replaced by the customer that uses the query):
With input1 as(
SELECT
(CASE WHEN exists(customerType) THEN customerType ELSE "0" END) as customerType, *
FROM table_customer_1)
SELECT * from input1
WHERE customerType != 2
Below is for BigQuery Standard SQL
#standardSQL
SELECT *
FROM `project.dataset.table` t
WHERE SAFE_CAST(IFNULL(JSON_EXTRACT_SCALAR(TO_JSON_STRING(t), '$.CustomerType'), '0') AS INT64) != 2
or as a simplification you can ignore casting to INT64 and use comparison to STRING
#standardSQL
SELECT *
FROM `project.dataset.table` t
WHERE IFNULL(JSON_EXTRACT_SCALAR(TO_JSON_STRING(t), '$.CustomerType'), '0') != '2'
above will work for whatever table you put instead of project.dataset.table: either project.dataset.table_customer_1 or project.dataset.table_customer_2 - so quite generic I think
I can think of no good reason for doing this. However, it is possible by playing with the scoping rules for subqueries:
SELECT t.*
FROM (SELECT t.*,
(SELECT customerType -- will choose from tt if available, otherwise x
FROM table_customer_1 tt
WHERE tt.Customerid = t.Customerid
) as customerType
FROM (SELECT t.* EXCEPT (Customerid)
FROM table_customer_1 t
) t CROSS JOIN
(SELECT 0 as customerType) x
) t
WHERE customerType <> 2
I have a table with two columns: col_order (int), and name (text). I would like to retrieve ordered rows such that, when col_order is not null, it determines the order, but when its null, then name determines the order. I thought of an order by clause such as
order by coalesce( col_order, name )
However, this won't work because the two columns have different type. I am considering converting both into bytea, but: 1) to convert the integer is there a better method than just looping moding by 256, and stacking up individual bytes in a function, and 2) how do I convert "name" to insure some sort of sane collation order (assuming name has order ... well citext would be nice but I haven't bothered to rebuild to get that ... UTF8 for the moment).
Even if all this is possible (suggestions on details welcome) it seems like a lot of work. Is there a better way?
EDIT
I got an excellent answer by Gordon, but it shows I didn't phrase the question correctly. I want a sort order by name where col_order represents places where this order is overridden. This isn't a well posed problem, but here is one acceptable solution:
col_order| name
----------------
null | a
1 | foo
null | foo1
2 | bar
Ie -- here if col_order is null name should be inserted after name closest in alphabetical order but less that it. Otherwise, this could be gotten by:
order by col_order nulls last, name
EDIT 2
Ok ... to get your creative juices flowing, this seems to be going in the right direction:
with x as ( select *,
case when col_order is null then null else row_number() over (order by col_order) end as ord
from temp )
select col_order, name, coalesce( ord, lag(ord,1) over (order by name) + .5) as ord from x;
It gets the order from the previous row, sorted by name, when there is no col_order. It isn't right in general... I guess I'd have to go back to the first row with non-null col_order ... it would seem that sql standard has "ignore nulls" for window functions which might do this, but isn't implemented in postgres. Any suggestions?
EDIT 3
The following would seem close -- but doesn't work. Perhaps window evaluation is a bit strange with recursive queries.
with recursive x(col_order, name, n) as (
select col_order, name, case when col_order is null then null
else row_number() over (order by col_order) * t end from temp, tot
union all
select col_order, name,
case when row_number() over (order by name) = 1 then 0
else lag(n,1) over (order by name) + 1 end from x
where x.n is null ),
tot as ( select count(*) as t from temp )
select * from x;
Just use multiple clauses:
order by (case when col_order is not null then 1 else 2 end),
col_order,
name
When col_order is not null, then 1 is assigned for the first sort key. When it is null, then 2 is assigned. Hence, the not-nulls will be first.
Ok .. the following seems to work -- I'll leave the question "unanswered" though pending criticism or better suggestions:
Using the last_agg aggregate from here:
with
tot as ( select count(*) as t from temp ),
x as (
select col_order, name,
case when col_order is null then null
else (row_number() over (order by col_order)) * t end as n,
row_number() over (order by name) - 1 as i
from temp, tot )
select x.col_order, x.name, coalesce(x.n,last_agg(y.n order by y.i)+x.i, 0 ) as n
from x
left join x as y on y.name < x.name
group by x.col_order, x.n, x.name, x.i
order by n;
I need to find a select statement that will return either a record that matches my input exactly, or the closest match if an exact match is not found.
Here is my select statement so far.
SELECT * FROM [myTable]
WHERE Name = 'Test' AND Size = 2 AND PType = 'p'
ORDER BY Area DESC
What I need to do is find the closest match to the 'Area' field, so if my input is 1.125 and the database contains 2, 1.5, 1 and .5 the query will return the record containing 1.
My SQL skills are very limited so any help would be appreciated.
get the difference between the area and your input, take absolute value so always positive, then order ascending and take the first one
SELECT TOP 1 * FROM [myTable]
WHERE Name = 'Test' and Size = 2 and PType = 'p'
ORDER BY ABS( Area - #input )
something horrible, along the lines of:
ORDER BY ABS( Area - 1.125 ) ASC LIMIT 1
Maybe?
If you have many rows that satisfy the equality predicates on Name, Size, and PType columns then you may want to include range predicates on the Area column in your query. If the Area column is indexed this could allow efficient index-based access.
The following query (written using Oracle syntax) uses one branch of a UNION ALL to find the record with minimal Area >= your target, while the other branch finds the record with maximal Area < your target. One of these two records will be the record that you are looking for. Then you can ORDER BY ABS(Area - ?input) to pick the winner out of those two candidates. Unfortunately the query is complex due to nested SELECTS that are needed to enforce the desired ROWNUM / ORDER BY precedence.
SELECT *
FROM
(SELECT * FROM
(SELECT * FROM
(SELECT * FROM [myTable]
WHERE Name = 'Test' AND Size = 2 AND PType = 'p' AND Area >= ?target
ORDER BY Area)
WHERE ROWNUM < 2
UNION ALL
SELECT * FROM
(SELECT * FROM [myTable]
WHERE Name = 'Test' AND Size = 2 AND PType = 'p' AND Area < ?target
ORDER BY Area DESC)
WHERE ROWNUM < 2)
ORDER BY ABS(Area - ?target))
WHERE rownum < 2
A good index for this query would be (Name, Size, PType, Area), in which case the expected query execution plan would be based on two index range scans that each returned a single row.
SELECT *
FROM [myTable]
WHERE Name = 'Test' AND Size = 2 AND PType = 'p'
ORDER BY ABS(Area - 1.125)
LIMIT 1
-- MarkusQ
How about ordering by the difference between your input and [Area], such as:
DECLARE #InputValue DECIMAL(7, 3)
SET #InputValue = 1.125
SELECT TOP 1 * FROM [myTable]
WHERE Name = 'Test' AND Size = 2 AND PType = 'p'
ORDER BY ABS(#InputValue - Area)
Note that although ABS() is supported by pretty much everything, it's not technically standard (in SQL99 at least). If you must write ANSI standard SQL for some reason, you'd have to work around the problem with a CASE operator:
SELECT * FROM myTable
WHERE Name='Test' AND Size=2 AND PType='p'
ORDER BY CASE Area>1.125 WHEN 1 THEN Area-1.125 ELSE 1.125-Area END
If using MySQL
SELECT * FROM [myTable] ... ORDER BY ABS(Area - SuppliedValue) LIMIT 1