I have written the below query and get good data,
What is the correct way to then have the gross hire less the discount show as net hire?? the script I wrote gives me a null value for 1 branch and I know this is incorrect?
SELECT branch_name, gross_hire_$, discount_$
FROM m_rental R, m_vehicle V, m_branch B
WHERE r.rego_no = v.rego_no
AND v.branch_code = b.branch_code
GROUP BY b.branch_code
ORDER BY branch_name
Assuming that your query won't throw ambiguous column error, this can work out for you. If you know that the discount can be null, use ifnull() while doing aggregates. If you are doing sums, then you can use sum(ifnull(discount,0)) but if you are doing averages and you want averages for non-zero records only then you'll have to do something like this:
sum(case when discount is not null then discount else 0 end)/
sum(case when discount is not null then 1 else 0 end)
But in the current scenario, the following should work out fine.
select branch_name, sum(ifnull(gross_hire,0)) as gross_hire,
sum(ifnull(discount,0)) as discount from m_rental r,
m_vehicle v, m_branch b where r.rego_no = v.rego_no
and v.brand_code = b.branch_code group by b.branch_code order by branch_name;
You can perform arithmetic in the column list of a SELECT, and anytime you have a column which might be null (and where you can replace null with some non-null value) you can use the SQL COALESCE function.
SELECT branch_name, gross_hire_$, discount_$, (gross_hire_$ - COALESCE(discount_$, 0)) AS net_hire_$
FROM m_rental R, m_vehicle V, m_branch B
WHERE r.rego_no = v.rego_no
AND v.branch_code = b.branch_code
GROUP BY b.branch_code
ORDER BY branch_name
should serve your purpose. The call COALESCE(discount_$, 0) returns the value of discount_$ unless it is null, in which case it returns 0.
Note that I have not attempted to sum any columns, but the principle still holds.
Related
I need to retrieve unique yet truncated part numbers, with their description values being conditionally determined.
DATA:
Here's some simplified sample data:
(the real table has half a million rows)
create table inventory(
partnumber VARCHAR(10),
description VARCHAR(10)
);
INSERT INTO inventory (partnumber,description) VALUES
('12345','ABCDE'),
('123456','ABCDEF'),
('1234567','ABCDEFG'),
('98765','ZYXWV'),
('987654','ZYXWVU'),
('9876543','ZYXWVUT'),
('abcde',''),
('abcdef','123'),
('abcdefg','321'),
('zyxwv',NULL),
('zyxwvu','987'),
('zyxwvut','789');
TRIED:
I've tried too many things to list here.
I've finally found a way to get past all the 'unknown field' errors and at least get SOME results, but:
it's SUPER kludgy!
my results are not limited to unique prods.
Here's my current query:
SELECT
LEFT(i.partnumber, 6) AS prod,
CASE
WHEN agg.cnt > 1
OR i.description IS NULL
OR i.description = ''
THEN LEFT(i.partnumber, 6)
ELSE i.description
END AS `descrip`
FROM inventory i
INNER JOIN (SELECT LEFT(ii.partnumber, 6) t, COUNT(*) cnt
FROM inventory ii GROUP BY ii.partnumber) AS agg
ON LEFT(i.partnumber, 6) = agg.t;
GOAL:
My goal is to retrieve:
prod
descrip
12345
ABCDE
123456
123456
98765
ZYXWV
987654
987654
abcde
abcde
abcdef
abcdef
zyxwv
zyxwv
zyxwvu
zyxwvu
QUESTION:
What are some cleaner ways to use the COUNT() aggregate data with a CASE type conditional?
How can I limit my results so that all prods are UNIQUE?
You can check if a left(partnumber, 6) is not unique in the result by checking if count(*) > 1. In such a case let descrip be left(partnumber, 6). Otherwise you can use max(description) (or min(description)) to get the single description but satisfy the needs to use an aggregation function on columns not in the GROUP BY. To replace empty or NULL descriptions, nullif() and coalesce() can be used.
That would lead to the following using just one level of aggregation and no joins:
SELECT left(partnumber, 6) AS prod,
CASE
WHEN count(*) > 1 THEN
left(partnumber, 6)
ELSE
coalesce(nullif(max(description), ''), left(partnumber, 6))
END AS descrip
FROM inventory
GROUP BY left(partnumber, 6)
ORDER BY left(partnumber, 6);
But there seems to be a bug in MySQL and this query fails. The engine doesn't "see" that, in the list after SELECT partnumber is only used in the expression left(partnumber, 6), which is also in the GROUP BY. Instead the engine falsely complains about partnumber not being in the GROUP BY and not subject to an aggregation function.
As a workaround, we can use a derived table, that does the shortening of partnumber to its first six characters. We then use use that column of the derived table instead of left(partnumber, 6).
SELECT l6pn AS prod,
CASE
WHEN count(*) > 1 THEN
l6pn
ELSE
coalesce(nullif(max(description), ''), l6pn)
END AS descrip
FROM (SELECT left(partnumber, 6) AS l6pn,
description
FROM inventory) AS x
GROUP BY l6pn
ORDER BY l6pn;
Or we slap some actually pointless max()es around the left(partnumber, 6) other than the first, to work around the bug.
SELECT left(partnumber, 6) AS prod,
CASE
WHEN count(*) > 1 THEN
max(left(partnumber, 6))
ELSE
coalesce(nullif(max(description), ''), max(left(partnumber, 6)))
END AS descrip
FROM inventory
GROUP BY left(partnumber, 6)
ORDER BY left(partnumber, 6);
db<>fiddle (Change the DBMS to some other like Postgres or MariaDB to see that they also accept the first query.)
I've got a dataset with a bunch of rows for monthly salary payments for each account. we have 6 columns for this -
Salary_1, Salary_2, Salary_3, Salary_4, Salary_5 and Salary_6.
Sometimes salaries 3, 4, 5, 6 and occasionally 2 aren't populated, sometimes none are populated because they're unemployed. In this case, we have 0 in the field.
What I need to do is combine all salaries and find the MAX and MIN from these columns ---
Select
Greatest(Salary_1, Salary_2, Salary_3, Salary_4, Salary_5, Salary_6) as MaxSal,
Least(COALESCE(Salary_1, Salary_2, Salary_3, Salary_4, Salary_5, Salary_6),0) as MinSal
from
(select
sal1 as Salary_1, Select sal2 as Salary_2, Sal3 as Salary_3, sal4 as Salary_4, Sal5 as Salary_5, Sal6 as Salary_6
from ....)a
The problem is, this is returning the correct value for Max Sal but 0.00 for Min, because it is the minimum value but won't let me ignore 0s, but in this case 0 is not a minimum salary value I want, I need the second lowest value here.
I've tried setting the original Sal1-Sal6 values to NULLIF 0 and it returns NULL for max and 0 for Min.
What else could I have a look at? the COALESCE combined with NULLIF has not worked for me which is what has been recommended on previous questions. Thanks!
Greatest and Least do not ignore nulls like aggregation functions do; you'll need to do something to avoid them. One option is something like this:
Greatest(IFNULL(Salary_1 ,0), ...)
Least(
CASE WHEN Salary_1 IS NULL OR Salary_1 = 0 THEN /*some huge value*/ ELSE Salary_1 END
, CASE WHEN Salary_2
....)
This might be simplest to unpivot and aggregate the data:
select id, max(salary), min(salary)
from ((select id, salary_1 as salary from t) union all
(select id, salary_2 as salary from t) union all
. . .
) t
group by id;
This is definitely more expensive than a giant case expression. On the other hand, it is less prone to error.
The real suggestion is to fix your data model. Trying to store an array in multiple columns is generally a sign of a poor data model. The more appropriate method would have one row per salary rather than putting them in separate columns.
PFB the query in which I want know the actual table where I can find these (pin_ein,engineer_pin,transaction_date,EFFECTIVE_WEEK )....
select count(1),pin_ein,engineer_pin,transaction_date,EFFECTIVE_WEEK from
(SELECT vw1.pin_ein, vw1.engineer_pin,
vw1.transaction_date, vw1.effective_week,
vw1.stores_tools_cost,
(vw1.stores_total_cost - vw1.stores_tools_cost
) stores_total_cost_excl_tools,
vw1.item_count, vw1.stores_visit_count,
CASE
WHEN vw1.stores_total_cost <
5
THEN vw1.stores_visit_count
END stores_low_cost_visit_count,
vw1.actual_ouc ouc, er.eng_name engineer_name,
CASE
WHEN c.home_parked IS NOT NULL
THEN c.home_parked
ELSE 'N'
END home_parker,
CASE
WHEN c.home_parked IS NOT NULL
THEN c.commute_time
ELSE -99
END commute_time,
vw1.stores_com_cost ---v9.3---
FROM (SELECT pin_ein, engineer_pin, actual_ouc,
transaction_date, effective_week,
NVL
(SUM
(CASE
WHEN ( cow LIKE '%TOOL%'
OR cow LIKE
'%TOOLE%'
)
THEN transaction_value
END
),
0
) stores_tools_cost,
SUM
(transaction_value
) stores_total_cost,
SUM (transaction_quantity)
item_count,
COUNT
(DISTINCT sta_code
) stores_visit_count,
NVL
(SUM
(CASE
WHEN cow in (SELECT cow FROM orbit_odw.stores_cow_ref)
THEN transaction_value
END
),
0
) stores_com_cost ---v9.3---
FROM orbit_odw.stores_transaction_dtls
WHERE effective_week BETWEEN 201543
AND 201610
/***Ver 6.0---last 13 weeks data to be considered***/
AND transaction_date
BETWEEN to_date('19-10-2015','dd-mm-yyyy')
AND to_date('06-03-2016','dd-mm-yyyy')
/***Ver 6.0---last 13 weeks data to be considered***/
GROUP BY pin_ein,
engineer_pin,
actual_ouc,
transaction_date,
effective_week) vw1,
(SELECT *
FROM orbit_odw.dim_wms_rmdm
WHERE current_status = 1) er,
(SELECT engineer_ein, commute_time,
home_parked
FROM orbit_odw.eng_parking_at_home_dtls
WHERE rec_end_date > SYSDATE
AND home_parked = 'Y') c
WHERE TO_CHAR (vw1.pin_ein) = er.ein
AND vw1.pin_ein = c.engineer_ein(+)) group by pin_ein,engineer_pin,transaction_date,EFFECTIVE_WEEK having count(1)>1;
Please help..
thanks in advance
Basically if i understand your problem correctly. You need to understand from where your outer SELECT is fetching data. So there is a simple rule set used to get these data. Steps are as follows.
Check the column output i.e in your case it's
pin_ein,engineer_pin,transaction_date,EFFECTIVE_WEEK
Check the inline view or table from which your outer query is
fetching the data. In your case its the only inline view you have
used --> So bit easy to identify :P
Now to identify how your inline view VW1 is populating data. In your
case table orbit_odw.stores_transaction_dtls is used to populate the
required fields.
Hope this much information is required. Also for simple queries you can always go to ALL_TAB_COLUMNS system tables to identify a table's column easily.
I want to select the number of users that has marked some content as favorite and also return if the current user has "voted" or not. My table looks like this
CREATE TABLE IF NOT EXISTS `favorites` (
`user` int(11) NOT NULL DEFAULT '0',
`content` int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (`user`,`content`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 ;
Say I have 3 rows containing
INSERT INTO `favorites` (`user`, `content`) VALUES
(11, 26977),
(22, 26977),
(33, 26977);
Using this
SELECT COUNT(*), CASE
WHEN user='22'
THEN 1
ELSE 0
END as has_voted
FROM favorites WHERE content = '26977'
I expect to get has_voted=1 and COUNT(*)=3 but
I get has_voted=0 and COUNT(*)=3. Why is that? How to fix it?
This is because you mixed aggregated and non-aggregated expressions in a single SELECT. Aggregated expressions work on many rows; non-aggregated expressions work on a single row. An aggregated (i.e. COUNT(*)) and a non-aggregated (i.e. CASE) expressions should appear in the same SELECT when you have a GROUP BY, which does not make sense in your situation.
You can fix your query by aggregating the second expression - i.e. adding a SUM around it, like this:
SELECT
COUNT(*) AS FavoriteCount
, SUM(CASE WHEN user=22 THEN 1 ELSE 0 END) as has_voted
FROM favorites
WHERE content = 26977
Now both expressions are aggregated, so you should get the expected results.
Try this with SUM() and without CASE
SELECT
COUNT(*),
SUM(USER = '22') AS has_voted
FROM
favorites
WHERE content = '26977'
See Fiddle Demo
Try this:
SELECT COUNT(*), MAX(USER=22) AS has_voted
FROM favorites
WHERE content = 26977;
Check the SQL FIDDLE DEMO
OUTPUT
| COUNT(*) | HAS_VOTED |
|----------|-----------|
| 3 | 1 |
You need sum of votes.
SELECT COUNT(*), SUM(CASE
WHEN user='22'
THEN 1
ELSE 0
END) as has_voted
FROM favorites WHERE content = '26977'
You are inadvertently using a MySQL feature here: You aggregate your results to get only one result record showing the number of matches (aggregate function COUNT). But you also show the user (or rather an expression built on it) in your result line (without any aggregate function). So the question is: Which user? Another dbms would have given you an error, asking you to either state the user in a GROUP BY or aggregate users. MySQL instead picks a random user.
What you want to do here is aggregate users (or rather have your expression aggregated). Use SUM to sum all votes the user has given on the requested content:
SELECT
COUNT(*),
SUM(CASE WHEN user='22' THEN 1 ELSE 0 END) as sum_votes
FROM favorites
WHERE content = '26977';
You forgot to wrap the CASE statement inside an aggregate function. In this case has_voted will contain unexpected results since you are actually doing a "partial group by". Here is what you need to do:
SELECT COUNT(*), SUM(CASE WHEN USER = 22 THEN 1 ELSE 0 END) AS has_voted
FROM favorites
WHERE content = 26977
Or:
SELECT COUNT(*), COUNT(CASE WHEN USER = 22 THEN 1 ELSE NULL END) AS has_voted
FROM favorites
WHERE content = 26977
I have a sql query as follow:
but the problem is that if the the second select staement with dataitem=3 returns null then the whole calculation becomes 0. For example for first select I have 100 and for second it returns null. Adding them should result 100 but it gives back 0!!!!!
can anyone say the reason and also what to do to get rid of that?
Here is also copiable code:
select( (
SELECT sum(Sentiment)
FROM entity_epoch_data
WHERE EpochID IN
(SELECT ID
FROM epoch
WHERE StartDateTime>='2013-11-1'
AND EndDateTime<='2013-11-30')
AND EntityID =86
AND DataitemType=0
)+
(SELECT sum(Sentiment)
FROM entity_epoch_data
WHERE EpochID IN
(SELECT ID
FROM epoch
WHERE StartDateTime>='2013-11-1'
AND EndDateTime<='2013-11-30')
AND EntityID =86
AND DataitemType=3)
)
Just add to the SQLs that represent values the IFNULL command like IFNULL((select sum()......), 0) it should work fine.
But a little peace of advice. You should improve that query.
I beleave that this query you do the same thing.
SELECT sum(entity_epoch_data.Sentiment)
FROM entity_epoch_data INNER JOIN epoch
ON entity_epoch_data.EpochID = epoch.id
WHERE epoch.StartDateTime>='2013-11-1'
and epoch.EndDateTime<='2013-11-30'
AND entity_epoch_data.EntityID =86
and entity_epoch_data.DataitemType in (0,3)
You are summing the sums of the DataitemType 3 and 0 it just can be one query with a join
Use CASE statements instead of the statements you're using.
select sum(case when StartDateTime>='2013-11-1' and EndDateTime<='2013-11-30' and DataitemType=0 then Sentiment else 0 end) as Sentiment_0, sum(case when StartDateTime>='2013-11-1' and EndDateTime<='2013-11-30' and DataitemType=3 then Sentiment else 0 end) as Sentiment3 from (tables_joined) where EntityID =86
Adding null is undefined and therefore returns null or 0. You can use a CASE expression to avoid that problem.
SELECT SUM(CASE null = sentiment THEN 0 ELSE sentiment END) FROM ....
If your DB does not support CASE inside the SUM() function create a VIEW that uses CASE to substitute the null values with 0.