This query works fine there is only one problem and that's his long execution time. Can someone show me some good optimizations and explain them.
SELECT TOP 5 PC.PersonID, P.FirstName, P.LastName, P.A, COUNT(*) Together
FROM PersonCheckIn PC
INNER JOIN Person P ON P.PersonID = PC.PersonID
WHERE CAST(CheckInDate AS DATE) IN (SELECT CAST(CheckInDate AS DATE)
FROM PersonCheckIn C
WHERE C.PersonId = 20) AND
PC.TimeTableID IN (SELECT CIn.TimeTableID
FROM PersonCheckIn CIn
WHERE CIn.PersonId = 20)
AND PC.PersonId <> 20 -- not count same person
GROUP BY PC.PersonId, P.FirstName, P.LastName, P.A
ORDER BY Together DESC;
Avoiding sub-queries and IN() Statement will drasticaly decrease execution time...
Even so CheckInDate is not prefixed with its table alias in your query (And we have to guess witch table is concerned :( ), maybe this will do the job :
SELECT TOP 5 PC.PersonID, P.FirstName, P.LastName, P.A, COUNT(*) Together
FROM PersonCheckIn PC
INNER JOIN Person P ON P.PersonID = PC.PersonID
INNER JOIN PersonCheckIn LU ON (LU.PersonId = 20 AND PC.CheckInDate = LU.CheckInDate AND PC.TimeTableID = LU.TimeTableID)
WHERE PC.PersonId <> 20 -- not count same person
GROUP BY PC.PersonId, P.FirstName, P.LastName, P.A
ORDER BY Together DESC;
If not, please :
- set the missing alias.
- give use data structure.
- give us data exemple.
- give us expected result exemple.
Related
I have a working PostgreSQL query, but it is taking a considerable amount of time to execute. I need help optimising it.
I have:
Removed inner queries as much as possible.
Removed the unnecessary data from the query.
Created a with query which gets the required data from the beginning
I need help to optimise this query
with data as (
select
e.id,
e.name,
t.barcode,
tt.variant,
t.cost_cents::decimal / 100 as ticket_cost,
t.fee_cents::decimal / 100 as booking_fee
from
tickets t
inner join events e on t.event_id = e.id
inner join ticket_types tt on t.ticket_type_id = tt.id
where
t.status = 2
and e.source in ('source1', 'source2')
)
select
d.name,
count(distinct d.barcode) as issued,
(select count(distinct d2.barcode) from data d2 where d2.id = d.id and d2.variant is null) as sold,
sum(d.ticket_cost) as ticket_revenue,
sum(d.booking_fee) as booking_fees
from
data d
group by
id,
name
Better to detect slow parts with using EXPLAIN .
It will show cost of all parts
You can speed up joins by creating proper indexes.
Also, remove the subquery
(select count(distinct d2.barcode) from data d2 where d2.id = d.id and d2.variant is null)
from the SELECT clause and add a join to d2 table something like this:
select
d.name,
count(distinct d.barcode) as issued,
count(distinct d2.barcode) as sold,
sum(d.ticket_cost) as ticket_revenue,
sum(d.booking_fee) as booking_fees
from
data d
left join data d2 on (d2.id = d.id and d2.variant is null)
group by
d.id,
d.name
We created a view in Postgres and I am getting strange result.
View Name: event_puchase_product_overview
When I try to get records with *, I get the correct result. but when I try to get specific fields, I get wrong values.
I hope the screens attached here can explain the problem well.
select *
from event_purchase_product_overview
where id = 15065;
select id, departure_id
from event_puchase_product_overview
where id = 15065;
VIEW definition:
CREATE OR REPLACE VIEW public.event_puchase_product_overview AS
SELECT row_number() OVER () AS id,
e.id AS departure_id,
e.type AS event_type,
e.name,
p.id AS product_id,
pc.name AS product_type,
product_date.attribute AS option,
p.upcomming_date AS supply_date,
pr.date_end AS bid_deadline,
CASE
WHEN (pt.categ_id IN ( SELECT unnest(tt.category_ids) AS unnest
FROM ( SELECT string_to_array(btrim(ir_config_parameter.value, '[]'::text), ', '::text)::integer[] AS category_ids
FROM ir_config_parameter
WHERE ir_config_parameter.key::text = 'trip_product_flight.product_category_hotel'::text) tt)) THEN e.maximum_rooms
WHEN (pt.categ_id IN ( SELECT unnest(tt.category_ids) AS unnest
FROM ( SELECT string_to_array(btrim(ir_config_parameter.value, '[]'::text), ', '::text)::integer[] AS category_ids
FROM ir_config_parameter
WHERE ir_config_parameter.key::text = 'trip_product_flight.product_category_flight'::text) tt)) THEN e.maximum_seats
WHEN (pt.categ_id IN ( SELECT unnest(tt.category_ids) AS unnest
FROM ( SELECT string_to_array(btrim(ir_config_parameter.value, '[]'::text), ', '::text)::integer[] AS category_ids
FROM ir_config_parameter
WHERE ir_config_parameter.key::text = 'trip_product_flight.product_category_bike'::text) tt)) THEN e.maximum_bikes
ELSE e.maximum_seats
END AS departure_qty,
CASE
WHEN now()::date > pr.date_end AND po.state::text = 'draft'::text THEN true
ELSE false
END AS is_deadline,
pl.product_qty::integer AS purchased_qty,
pl.comments,
pl.price_unit AS unit_price,
rp.id AS supplier,
po.id AS po_ref,
po.state AS po_state,
po.date_order AS po_date,
po.user_id AS operator,
pl.po_state_line AS line_status
FROM event_event e
LEFT JOIN product_product p ON p.related_departure = e.id
LEFT JOIN product_template pt ON pt.id = p.product_tmpl_id
LEFT JOIN product_category pc ON pc.id = pt.categ_id
LEFT JOIN purchase_order_line pl ON pl.product_id = p.id
LEFT JOIN purchase_order po ON po.id = pl.order_id
LEFT JOIN purchase_order_purchase_requisition_rel prr ON prr.purchase_order_id = po.id
LEFT JOIN purchase_requisition pr ON pr.id = prr.purchase_requisition_id
LEFT JOIN res_partner rp ON rp.id = po.partner_id
LEFT JOIN ( SELECT p_1.id AS product_id,
pav.name AS attribute
FROM product_product p_1
LEFT JOIN product_attribute_value_product_product_rel pa ON pa.prod_id = p_1.id
LEFT JOIN product_attribute_value pav ON pav.id = pa.att_id
LEFT JOIN product_attribute pat ON pat.id = pav.attribute_id
WHERE pat.name::text <> ALL (ARRAY['Date'::character varying, 'Departure'::character varying]::text[])) product_date ON product_date.product_id = p.id
WHERE (p.id IN ( SELECT DISTINCT mrp_bom_line.product_id
FROM mrp_bom_line)) AND p.active
ORDER BY e.id, pt.categ_id, p.id;
If I add new event_event or new product_product I'll get a new definition of row_number in my view, then the column ID of my view is not stable.
at least you can't use row_number as Id of the view,
If you insist to use row_number, you can use the Order By "creation DATE" by this way all new records will be as last lines in the view and this will not change the correspondency between ID (row_number) and other columns.
Hope that helps !
Very likely the execution plan of your query depends on the columns you select. Compare the execution plans!
Your id is generated using the row_number window function. Now window functions are executed before the ORDER BY clause, so the order will depend on the execution plan and hence on the columns you select.
Using row_number without an explicit ordering doesn't make any sense.
To fix that, don't use
row_number() OVER ()
but
row_number() OVER (ORDER BY e.id, pt.categ_id, p.id)
so that you have a reliable ordering.
In addition, you should omit the ORDER BY clause at the end.
I have the below problem. Seems to be a simple query, but I couldn't figure it out after spending so much time.
Table
-----
project
mission
craft
project can have many missions, for each mission, it can use multiple air crafts. I want to identify the crafts that was involved with all the missions.
For eg if there are 10 missions, mission 1 can use craft 1 and 2. If there is any craft that used for all the 10 missions (mission 1 -10), that should be output.
I wrote,
select craft,count(mission) from table group by craft
After this I don't know how can I match this value to the total missions. Any help would be highly appreciated.
If you need this for single project you need filter number of craft's missions by total number of missions:
select c.id from (
select c.id, count(mission_id) cnt
from craft c inner join mission m on (m.id = c.mission_id)
where m.project_id = <project_id>
group by c.id
) as c
where c.cnt = (select count(*) from mission where project_id = <project_id>)
If you need this for all projects:
select c.project_id, c.id from (
select m.project_id, c.id, count(mission_id) cnt
from craft c inner join mission m on (m.id = c.mission_id)
group by m.project_id, c.id
) as c inner join (
select project_id, count(*) cnt
from mission
group by project_id
) as m on (m.project_id = c.project_id)
where c.cnt = m.cnt
with mission as (
select distinct mission
from craft
), craft_missions as (
select craft, count(*) as total_missions
from
craft c
inner join
mission m on m.mission = c.mission
group by craft
)
select craft
from craft_missions
where total_missions = (select count(*) from mission)
I want to do a similiar thing like this guy:
T-SQL Subquery Max(Date) and Joins
I have to do this with an n:m relation.
So the layout is:
tbl_Opportunity
tbl_Opportunity_tbl_OpportunityData
tbl_OpportunityData
So as you see there is an intersection table which connects opportunity with opportunitydata.
For every opportunity there are multiple opportunity datas. In my view i only want a list with all opportunites and the data from the latest opportunity datas.
I tried something like this:
SELECT
dbo.tbl_Opportunity.Id, dbo.tbl_Opportunity.Subject,
dbo.tbl_User.UserName AS Responsible, dbo.tbl_Contact.Name AS Customer,
dbo.tbl_Opportunity.CreationDate, dbo.tbl_Opportunity.ActionDate AS [Planned Closure],
dbo.tbl_OpportunityData.Volume,
dbo.tbl_OpportunityData.ChangeDate, dbo.tbl_OpportunityData.Chance
FROM
dbo.tbl_Opportunity
INNER JOIN
dbo.tbl_User ON dbo.tbl_Opportunity.Creator = dbo.tbl_User.Id
INNER JOIN
dbo.tbl_Contact ON dbo.tbl_Opportunity.Customer = dbo.tbl_Contact.Id
INNER JOIN
dbo.tbl_Opprtnty_tbl_OpprtnityData ON dbo.tbl_Opportunity.Id = dbo.tbl_Opprtnty_tbl_OpprtnityData.Id
INNER JOIN
dbo.tbl_OpportunityData ON dbo.tbl_Opprtnty_tbl_OpprtnityData.Id2 = dbo.tbl_OpportunityData.Id
The problem is my view now includes a row for every opportunity data, since I don't know how to filter that I only want the latest data.
Can you help me? is my problem description clear enough?
thank you in advance :-)
best wishes,
laurin
; WITH Base AS (
SELECT dbo.tbl_Opportunity.Id, dbo.tbl_Opportunity.Subject, dbo.tbl_User.UserName AS Responsible, dbo.tbl_Contact.Name AS Customer,
dbo.tbl_Opportunity.CreationDate, dbo.tbl_Opportunity.ActionDate AS [Planned Closure], dbo.tbl_OpportunityData.Volume,
dbo.tbl_OpportunityData.ChangeDate, dbo.tbl_OpportunityData.Chance
FROM dbo.tbl_Opportunity INNER JOIN
dbo.tbl_User ON dbo.tbl_Opportunity.Creator = dbo.tbl_User.Id INNER JOIN
dbo.tbl_Contact ON dbo.tbl_Opportunity.Customer = dbo.tbl_Contact.Id INNER JOIN
dbo.tbl_Opprtnty_tbl_OpprtnityData ON dbo.tbl_Opportunity.Id = dbo.tbl_Opprtnty_tbl_OpprtnityData.Id INNER JOIN
dbo.tbl_OpportunityData ON dbo.tbl_Opprtnty_tbl_OpprtnityData.Id2 = dbo.tbl_OpportunityData.Id
)
, OrderedByDate AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY Id ORDER BY ChangeDate DESC) RN FROM Base
)
SELECT * FROM OrderedByDate WHERE RN = 1
To make it more readable I'm using CTE (the WITH part). In the end the real "trick" is doing a ROW_NUMBER() partitioning the data by tbl_Opportunity.Id and ordering the partitions by ChangeDate DESC (and I call it RN). Clearly the maximum date in each partition will be RN = 1 and then we filter it by RN.
Without using CTE it will be something like this:
SELECT * FROM (
SELECT dbo.tbl_Opportunity.Id, dbo.tbl_Opportunity.Subject, dbo.tbl_User.UserName AS Responsible, dbo.tbl_Contact.Name AS Customer,
dbo.tbl_Opportunity.CreationDate, dbo.tbl_Opportunity.ActionDate AS [Planned Closure], dbo.tbl_OpportunityData.Volume,
dbo.tbl_OpportunityData.ChangeDate, dbo.tbl_OpportunityData.Chance,
ROW_NUMBER() OVER (PARTITION BY dbo.tbl_Opportunity.Id ORDER BY dbo.tbl_OpportunityData.ChangeDate DESC) RN
FROM dbo.tbl_Opportunity INNER JOIN
dbo.tbl_User ON dbo.tbl_Opportunity.Creator = dbo.tbl_User.Id INNER JOIN
dbo.tbl_Contact ON dbo.tbl_Opportunity.Customer = dbo.tbl_Contact.Id INNER JOIN
dbo.tbl_Opprtnty_tbl_OpprtnityData ON dbo.tbl_Opportunity.Id = dbo.tbl_Opprtnty_tbl_OpprtnityData.Id INNER JOIN
dbo.tbl_OpportunityData ON dbo.tbl_Opprtnty_tbl_OpprtnityData.Id2 = dbo.tbl_OpportunityData.Id
) AS Base WHERE RN = 1
The statement can be simplified for one more step further:
SELECT TOP 1 WITH TIES
dbo.tbl_Opportunity.Id, dbo.tbl_Opportunity.Subject, dbo.tbl_User.UserName AS Responsible,
dbo.tbl_Contact.Name AS Customer, dbo.tbl_Opportunity.CreationDate,
dbo.tbl_Opportunity.ActionDate AS [Planned Closure], dbo.tbl_OpportunityData.Volume,
dbo.tbl_OpportunityData.ChangeDate, dbo.tbl_OpportunityData.Chance
FROM
dbo.tbl_Opportunity INNER JOIN
dbo.tbl_User ON dbo.tbl_Opportunity.Creator = dbo.tbl_User.Id INNER JOIN
dbo.tbl_Contact ON dbo.tbl_Opportunity.Customer = dbo.tbl_Contact.Id INNER JOIN
dbo.tbl_Opprtnty_tbl_OpprtnityData ON dbo.tbl_Opportunity.Id = dbo.tbl_Opprtnty_tbl_OpprtnityData.Id INNER JOIN
dbo.tbl_OpportunityData ON dbo.tbl_Opprtnty_tbl_OpprtnityData.Id2 = dbo.tbl_OpportunityData.Id
ORDER BY
ROW_NUMBER() OVER (PARTITION BY dbo.tbl_Opportunity.Id ORDER BY dbo.tbl_OpportunityData.ChangeDate DESC);
I'm having some trouble trying to get Microsoft Access 2007 to accept my SQL query but it keeps throwing syntax errors at me that don't help me correct the problem.
I have two tables, let's call them Customers and Orders for ease.
I need some customer details, but also a few details from the most recent order. I currently have a query like this:
SELECT c.ID, c.Name, c.Address, o.ID, o.Date, o.TotalPrice
FROM Customers c
INNER JOIN Orders o
ON c.ID = o.CustomerID
AND o.ID = (SELECT TOP 1 ID FROM Orders WHERE CustomerID = c.ID ORDER BY Date DESC)
To me, it appears valid, but Access keeps throwing 'syntax error's at me and when I hit OK, it selects a piece of the SQL text that doesn't even relate to it.
If I take the extra SELECT clause out it works but is obviously not what I need.
Any ideas?
You cannot use AND in that way in MS Access, change it to WHERE. In addition, you have two reserved words in your column (field) names - Name, Date. These should be enclosed in square brackets when not prefixed by a table name or alias, or better, renamed.
SELECT c.ID, c.Name, c.Address, o.ID, o.Date, o.TotalPrice
FROM Customers c
INNER JOIN Orders o
ON c.ID = o.CustomerID
WHERE o.ID = (
SELECT TOP 1 ID FROM Orders
WHERE CustomerID = c.ID ORDER BY [Date] DESC)
I worked out how to do it in Microsoft Access. You INNER JOIN on a pre-sorted sub-query. That way you don't have to do multiple ON conditions which aren't supported.
SELECT c.ID, c.Name, c.Address, o.OrderNo, o.OrderDate, o.TotalPrice
FROM Customers c
INNER JOIN (SELECT * FROM Orders ORDER BY OrderDate DESC) o
ON c.ID = o.CustomerID
How efficient this is another story, but it works...