I had a query made on aurora sql, it was working nice, but now I need to do the same in redshift, but when I do so, it throws an error asking me to group by by every column, but obviously I don't want that.
This is the query:
select
rut,
name,
id,
sum(cantidad_retornos) as cantidad_retornos,
sum(cantidad_aceptadas) as cantidad_aceptadas,
sum(cantidad_auto_accept) as cantidad_auto_accept,
sum(cantidad_rechazadas) as cantidad_rechazadas,
sum(cantidad_aceptadas) - sum(cantidad_auto_accept) as cantidad_aceptadas_manual,
coalesce((sum(cantidad_aceptadas) - sum(cantidad_auto_accept)) / nullif(sum(cantidad_aceptadas),0)) as per_aceptadas_manual,
coalesce(sum(cantidad_auto_accept) / nullif(sum(cantidad_aceptadas),0),0) as per_aceptadas_auto,
coalesce(sum(cantidad_rechazadas) / nullif(sum(cantidad_retornos),0),0) AS rechazo_per,
case
when coalesce(sum(cantidad_rechazadas) / nullif(sum(cantidad_retornos),0) ,0) < 0.1 or cantidad_retornos < 10 then 'Confiable'
when coalesce(sum(cantidad_rechazadas) / nullif(sum(cantidad_retornos),0),0) >= 0.1 and coalesce(sum(cantidad_rechazadas) / nullif(sum(cantidad_retornos),0),0) < 0.5 then 'Estándar'
when coalesce(sum(cantidad_rechazadas) / nullif(sum(cantidad_retornos),0),0) >= 0.5 then 'Poco confiable'
else 'Sin clasificar'
end as nivel_confianza
from table
where 1=1
group by id, name, rut
I tried to group by every column, but it doesn't throw the result that I need
The error that I get:
ERROR: column "reporte_sellers_date.cantidad_retornos" must appear in the GROUP BY clause or be used in an aggregate function
If I group by the third column, it throws the same error but with the column number 4
In the first option in the CASE statement you have or cantidad_retornos without any aggregating function such as SUM(). This is why Redshift is saying it needs to be in a group by. You also alias this name to the sum of the column of the same name. So the is a choice the database needs to make about which one to use - the source column or the aggregate. It looks like Aurora is choosing the aggregate but Redshift is choosing the source column.
Using the same name for an aggregate as a source column is not a good idea as you are relying on the query compiler to make a choice for you. This means the query can break when the compiler is updated or if you port the query to a different database.
To fix this you can either add the SUM() aggregation to the use of cantidad_retornos in the CASE statement or use the aggregate from above in the query but give it a unique name.
Related
I'm using PostgreSQL 10 and trying to run this query. I started with a CTE which I am referencing as 'query.'
SELECT
ROW_NUMBER()OVER() AS my_new_id,
query.geom AS geom,
query.pop AS pop,
query.name,
query.distance AS dist,
query.amenity_size,
((amenity_size)/(distance)^2) AS attract_score,
SUM((amenity_size)/(distance)^2) AS tot_attract_score,
((amenity_size)/(distance)^2) / SUM((amenity_size)/(distance)^2) as marketshare
INTO table_mktshare
FROM query
WHERE
distance > 0
GROUP BY
query.name,
query.amenity_size,
query.geom,
query.pop,
query.distance
The query runs but the problem lies in the 'markeshare' column. It returns the same answer with or without the SUM operator and returns one, which appears to make both the attract_score and the tot_attract_score the same. Why is the SUM operator read the same as the expression above it?
This is occurring specifically because each combination of columns in the group by clause uniquely identifies one row in the table. I don't know if this is intentional, but more normally, one would expect something like this:
SELECT ROW_NUMBER() OVER() AS my_new_id,
query.geom AS geom, query.pop AS pop, query.name,
SUM((amenity_size)/(distance)^2) AS tot_attract_score,
INTO table_mktshare
FROM query
WHERE distance > 0
GROUP BY query.name, query.geom, query.pop;
This is not your intention, but it does give a flavor of what's expected.
I am trying to get the max value of column A ("original_list_price") over windows defined by 2 columns (namely - a unique identifier, called "address_token", and a date field, called "list_date"). I.e. I would like to know the max "original_list_price" of rows with both the same address_token AND list_date.
E.g.:
SELECT
address_token, list_date, original_list_price,
max(original_list_price) OVER (PARTITION BY address_token, list_date) as max_list_price
FROM table1
The query already takes >10 minutes when I use just 1 expression in the PARTITION (e.g. using address_token only, nothing after that). Sometimes the query times out. (I use Mode Analytics and get this error: An I/O error occurred while sending to the backend) So my questions are:
1) Will the Window function with multiple PARTITION BY expressions work?
2) Any other way to achieve my desired result?
3) Any way to make Windows functions, especially the Partition part run faster? e.g. use certain data types over others, try to avoid long alphanumeric string identifiers?
Thank you!
The complexity of the window functions partitioning clause should not have a big impact on performance. Do realize that your query is returning all the rows in the table, so there might be a very large result set.
Window functions should be able to take advantage of indexes. For this query:
SELECT address_token, list_date, original_list_price,
max(original_list_price) OVER (PARTITION BY address_token, list_date) as max_list_price
FROM table1;
You want an index on table1(address_token, list_date, original_list_price).
You could try writing the query as:
select t1.*,
(select max(t2.original_list_price)
from table1 t2
where t2.address_token = t1.address_token and t2.list_date = t1.list_date
) as max_list_price
from table1 t1;
This should return results more quickly, because it doesn't have to calculate the window function value first (for all rows) before returning values.
I'm trying to write a few Oracle SQL scripts for an assignment. I've managed to get all of it to work, except for one part. To summarize, I have to display data from 2 tables if the average of 1 column in table A is greater than the average of another column in table B. I realize you cannot include AVG functions in a WHERE clause or HAVING clause since it seems unable to properly access the data (from what I've read). When I exclude this clause, the script executes properly, so I'm confident there are no other errors.
I've tried writing it as follows but the error I get is ORA-00936: missing expression and it is just before the > sign. I thought this may be due to improper bracket placing but none of my attempts resolved this. Here is my attempt:
SELECT l.l_category, SUM(r.r_sold), AVG(l.l_cost)
FROM promos l
INNER JOIN sales r
ON r.promo_id = l.promo_id
GROUP BY l.l_category
HAVING (SELECT AVG(l.l_cost) OVER (PARTITION BY l.l_cost)) >
(SELECT AVG(r.r_sold) OVER (PARTITION BY r.r_sold));
I tried doing this without the OVER (PARTITION BY ...) as well as putting it into a WHERE clause but it didn't resolve the error. I'm pretty sure I need to put it into a SELECT statement somehow but I'm at a loss.
You do not need to use the OVER clause when applying the aggregate functions in the HAVING clause. Just use the aggregate functions on their own.
SELECT l.l_category, SUM(r.r_sold), AVG(l.l_cost)
FROM promos l
INNER JOIN sales r
ON r.promo_id = l.promo_id
GROUP BY l.l_category
HAVING HAVING AVG(l.l_cost) > AVG(r.r_sold)
If I have a field in my SQL 2008 report that is generated via expression (meaning not directly from a dataset) should I be able to SUM it? Can I reference the field in a subsequent expression somehow - like by referencing the box name?
Your question isn't completely clear... but I'll take a stab at it.
Do you mean something like this:
SELECT SUM(GET_RANDOM_NUMBER()) as randomSum
FROM Table_That_Has_Infinite_Rows
WHERE rowId BETWEEN 3 AND 8
This will sum 6 numbers (because the range of a BETWEEN statement is inclusive on both ends).
You won't be able to reference the field alias 'immediately' in the WHERE clause -
SELECT SUM(GET_RANDOM_NUMBER()) as randomSum
FROM Table_With_One_Row
WHERE randomSum > 5 -- throws error, field 'does not exist'
However, it will be available in ORDER BY and GROUP BY clauses, and also if you wrap the query in something else (CTE, inline table, etx);
SELECT SUM(GET_RANDOM_NUMBER()) as randomSum
FROM Table_With_Thousand_Rows
GROUP BY randomSum -- although this won't have any apparent effect here
So I got this statement, which works fine:
SELECT MAX(patient_history_date_bio) AS med_date, medication_name
FROM biological
WHERE patient_id = 12)
GROUP BY medication_name
But, I would like to have the corresponding medication_dose also. So I type this up
SELECT MAX(patient_history_date_bio) AS med_date, medication_name, medication_dose
FROM biological
WHERE (patient_id = 12)
GROUP BY medication_name
But, it gives me an error saying:
"coumn 'biological.medication_dose' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.".
So I try adding medication_dose to the GROUP BY clause, but then it gives me extra rows that I don't want.
I would like to get the latest row for each medication in my table. (The latest row is determined by the max function, getting the latest date).
How do I fix this problem?
Use:
SELECT b.medication_name,
b.patient_history_date_bio AS med_date,
b.medication_dose
FROM BIOLOGICAL b
JOIN (SELECT y.medication_name,
MAX(y.patient_history_date_bio) AS max_date
FROM BIOLOGICAL y
GROUP BY y.medication_name) x ON x.medication_name = b.medication_name
AND x.max_date = b.patient_history_date_bio
WHERE b.patient_id = ?
If you really have to, as one quick workaround, you can apply an aggregate function to your medication_dose such as MAX(medication_dose).
However note that this is normally an indication that you are either building the query incorrectly, or that you need to refactor/normalize your database schema. In your case, it looks like you are tackling the query incorrectly. The correct approach should the one suggested by OMG Poinies in another answer.
You may be interested in checking out the following interesting article which describes the reasons behind this error:
But WHY Must That Column Be Contained in an Aggregate Function or the GROUP BY clause?
You need to put max(medication_dose) in your select. Group by returns a result set that contains distinct values for fields in your group by clause, so apparently you have multiple records that have the same medication_name, but different doses, so you are getting two results.
By putting in max(medication_dose) it will return the maximum dose value for each medication_name. You can use any aggregate function on dose (max, min, avg, sum, etc.)