I have a table with a certain flag called FL_virtual, if this flag equals 1 i need to get my stock in a special way using a function
now i want to make a select statement with it but depending on this flag i need to adjust my select to use a certain function instead of a subquery
so presume i start with this select statement
select product_name,..(other options from the product table),
(select sum(qy_stock) from STOCK where warehouse_id = 1) as 'qy_stock_internal',
(select sum(qy_stock) from STOCK where warehouse_id = 2) as qy_stock_external
From product
now i need to change the subquery (qy_stock) with a call to a function when the fl_virtual flag is 1
so that it becomes like this
select product_name,..(other options from the product table),
FN_GET_stock_PRODUCT(1) as qy_stock_internal,
FN_GET_stock_PRODUCT(2) as qy_stock_external
from product
so i thought a simple if then else structure will do but for some reason i can't get it to work
this is how i thought it would look
select product_name,..(other options from the product table),
IF fl_virtual > 0 THEN
(select sum(qy_stock) from STOCK where warehouse_id = 1) as 'qy_stock_internal',
(select sum(qy_stock) from STOCK where warehouse_id = 2) as qy_stock_external
ELSE
FN_GET_stock_PRODUCT(1) as qy_stock_internal,
FN_GET_stock_PRODUCT(2) as qy_stock_external
END IF
but it doesn't work , anyone got an idea?
You're close - just use CASE instead of IF (you have to repeat your condition, since you cannot easily return two columns from a single CASE (see P.S.):
select product_name,
..(other options from the product table),
(CASE
WHEN fl_virtual > 0 THEN
(select sum(qy_stock) from STOCK where warehouse_id = 1)
ELSE
FN_GET_stock_PRODUCT(1)
END) as qy_stock_internal,
(CASE
WHEN fl_virtual > 0 THEN
(select sum(qy_stock) from STOCK where warehouse_id = 2)
ELSE
FN_GET_stock_PRODUCT(2)
END) as qy_stock_external
P.S.: It is possible to return multiple values from a single CASE, e.g. using Object Types, but that's stuff for a different question :-)
Best way is to use a union select with those 2 different queries and contitions.
Btw. the names stock and warehouse look like a typical school work examin.
Related
How to use CASE to show 'debtor' if at least one of the invoices is not paid (Invoice_Status = 1)?
*(A customer has multiple invoices)
Here's the query to show the an Id_Customer and the status of his multiple invoices, but this repeats the Id_Customer for each invoice he has
SELECT Id_Customer,
CASE Invoice_Status
WHEN 1 THEN 'Debtor'
ELSE 'No debts'
END AS Status
FROM Tb_Invoices
ORDER BY Id_Customer
GO
You need to use an aggregate (min, max, count etc) on Invoice_Status, then map that value via you case statement. You haven't told us about your schema or data so we can't really help you more than that. I.e. something like this:
SELECT CASE
WHEN count(Invoice_Status = 1) > 0 THEN 'Dector'
ELSE 'No debts'
END
FROM Tb_Invoices
ORDER BY Id_Customer
I have a file that i receive each morning which contains details of customers whos information doesnt meet certain criteria, i have built a script with many WHERE conditions that, if met, will show customers information and put them in a file but im having trouble finding out why they are wrong.
As i have many conditions in the where clause, is there a way to show which column has the incorrect information
For example i could have a table like this:
NAME|ADDRESS |PHONE|COUNTRY
John|123avenue |12345|UK
My conditions could be
SELECT * FROM CUSTOMERS
WHERE NAME LIKE 'J%'
AND LEFT(PHONE,1) = '1'
so it would show in the file as two conditions are met, but as i have over 80 rows and 40 conditions, its hard to look at each row and find out why its in their.
Is there a way i can add a column which will tell me which WHERE condition has been met?
As worded, no. You should reverse your logic. Add fields that show what's wrong, then use those fields in a WHERE clause.
SELECT
*,
CASE WHEN LEFT(phone, 1) = '1' THEN 1 ELSE 0 END AS phone_starts_with_1,
CASE WHEN LEFT(name, 1) = 'Z' THEN 1 ELSE 0 END AS name_starts_with_z
FROM
customers
WHERE
phone_starts_with_1 = 1
OR name_starts_with_z = 1
Depending on which dialect of SQL you use, you may need to nest this, such that the new fields are resolved before you can use them in the WHERE clause...
SELECT
*
FROM
(
SELECT
*,
CASE WHEN LEFT(phone, 1) = '1' THEN 1 ELSE 0 END AS phone_starts_with_1,
CASE WHEN LEFT(name, 1) = 'Z' THEN 1 ELSE 0 END AS name_starts_with_z
FROM
customers
)
checks
WHERE
phone_starts_with_1 = 1
OR name_starts_with_z = 1
I have the following query where if brand1/camp1 taken individually, query returns the correct value but if I specify more than one brand or campaigns, it returns some other number and I am not sure what the math is behind that. It is not the total of the two either.
I think it is IN operator that is specifying OR with "," as opposed to what I require it to do which is consider AND
select campaign,
sum(case when campaign in ('camp1', 'camp2') and description in ('brand1', 'brand2') then orders else 0 end) as brand_convs
from data.camp_results
where campaign in ('camp1', 'camp2') and channel='prog' and type='sbc'
group by campaign
having brand_convs > 0
order by brand_convs desc;
Any thoughts?
The problem is in the IN part as you suspected: The two IN operators do not affect eachother in any way, so campaign can be camp1 while description is brand2.
If your DBMS supports multiple columns in an IN statement, you use a single IN statement:
SELECT campaign, SUM(
CASE WHEN (campaign, description) IN (
('camp1', 'brand1'),
('camp2', 'brand2')
) THEN orders ELSE 0 END
) [rest of query...]
If not, you're probably going to have to use ANDs and ORs
SELECT campaign, SUM(
CASE WHEN
(campaign='camp1' AND description='brand1')
OR (campaign='camp2' AND description='brand2')
THEN orders ELSE 0 END
) [rest of query...]
I'm trying to avoid using straight up SQL in my Rails app, but need to do a quite large version of this:
SELECT ds.product_id,
( SELECT SUM(units) FROM daily_sales WHERE (date BETWEEN '2015-01-01' AND '2015-01-08') AND service_type = 1 ) as wk1,
( SELECT SUM(units) FROM daily_sales WHERE (date BETWEEN '2015-01-09' AND '2015-01-16') AND service_type = 1 ) as wk2
FROM daily_sales as ds group by ds.product_id
I'm sure it can be done, but i'm struggling to write this as an active record statement. Can anyone help?
If you must do this in a single query, you'll need to write some SQL for the CASE statements. The following is what you need:
ranges = [ # ordered array of all your date-ranges
Date.new(2015, 1, 1)..Date.new(2015, 1, 8),
Date.new(2015, 1, 9)..Date.new(2015, 1, 16)
]
overall_range = (ranges.first.min)..(ranges.last.max)
grouping_sub_str = \
ranges.map.with_index do |range, i|
"WHEN (date BETWEEN '#{range.min}' AND '#{range.max}') THEN 'week#{i}'"
end.join(' ')
grouping_condition = "CASE #{grouping_sub_str} END"
grouping_columns = ['product_id', grouping_condition]
DailySale.where(date: overall_range).group(grouping_columns).sum(:units)
That will produce a hash with array keys and numeric values. A key will be of the form [product_id, 'week1'] and the value will be the corresponding sum of units for that week.
Simplify your SQL to the following and try converting it..
SELECT ds.product_id,
, SUM(CASE WHEN date BETWEEN '2015-01-01' AND '2015-01-08' AND service_type = 1
THEN units
END) WK1
, SUM(CASE WHEN date BETWEEN '2015-01-09' AND '2015-01-16' AND service_type = 1
THEN units
END) WK2
FROM daily_sales as ds
group by ds.product_id
Every rail developer sooner or later hits his/her head against the walls of Active Record query interface just to find the solution in Arel.
Arel gives you the flexibility that you need in creating your query without using loops, etc. I am not going to give runnable code rather some hints how to do it yourself:
We are going to use arel_tables to create our query. For a model called for example Product, getting the Arel table is as easy as products = Product.arel_table
Getting sum of a column is like daily_sales.project(daily_sales[:units].count).where(daily_sales[:date].gt(BEGIN_DATE).where(daily_sales[:date].lt(END_DATE). You can chain as many wheres as you want and it will be translated into SQL ANDs.
Since we need to have multiple sums in our end result you need to make use of Common Table Expressions(CTE). Take a look at docs and this answer for more info on this.
You can use those CTEs from step 3 in combination with group and you are done!
I get an error unless I remove one of the count(distinct ...). Can someone tell me why and how to fix it?
I'm in vfp. iif([condition],[if true],[else]) is equivalent to case when
SELECT * FROM dpgift where !nocalc AND rectype = "G" AND sol = "EM112" INTO CURSOR cGift
SELECT
list_code,
count(distinct iif(language != 'F' AND renew = '0' AND type = 'IN',donor,0)) as d_Count_E_New_Indiv,
count(distinct iif(language = 'F' AND renew = '0' AND type = 'IN',donor,0)) as d_Count_F_New_Indiv /*it works if i remove this*/
FROM cGift gift
LEFT JOIN
(select didnumb, language, type from dp) d
on cast(gift.donor as i) = cast(d.didnumb as i)
GROUP BY list_code
ORDER by list_code
edit:
apparently, you can't use multiple distinct commands on the same level. Any way around this?
VFP does NOT support two "DISTINCT" clauses in the same query... PERIOD... I've even tested on a simple table of my own, DIRECTLY from within VFP such as
select count( distinct Col1 ) as Cnt1, count( distinct col2 ) as Cnt2 from MyTable
causes a crash. I don't know why you are trying to do DISTINCT as you are just testing a condition... I more accurately appears you just want a COUNT of entries per each category of criteria instead of actually DISTINCT
Because you are not "alias.field" referencing your columns in your query, I don't know which column is the basis of what. However, to help handle your DISTINCT, and it appears you are running from WITHIN a VFP app as you are using the "INTO CURSOR" clause (which would not be associated with any OleDB .net development), I would pre-query and group those criteria, something like...
select list_code,
donor,
max( iif( language != 'F' and renew = '0' and type = 'IN', 1, 0 )) as EQualified,
max( iif( language = 'F' and renew = '0' and type = 'IN', 1, 0 )) as FQualified
from
list_code
group by
list_code,
donor
into
cursor cGroupedByDonor
so the above will ONLY get a count of 1 per donor per list code, no matter how many records that qualify. In addition, if one record as an "F" and another does NOT, then you'll have a value of 1 in EACH of the columns... Then you can do something like...
select
list_code,
sum( EQualified ) as DistEQualified,
sum( FQualified ) as DistFQualified
from
cGroupedByDonor
group by
list_code
into
cursor cDistinctByListCode
then run from that...
You can try using either another derived table or two to do the calculations you need, or using projections (queries in the field list). Without seeing the schema, it's hard to know which one will work for you.