Background: First post so go easy on me! ;-) I'm having some problems with a SQLite join across 5 tables. I'm building a watering system on my Raspberry Pi, using Python, with the following table structure built in SQLite:
deviceTable - table lists all watering devices
programTable - table listing all watering programs
zoneTable - table listing all watering zones
assignProgramTable - bridging table for assigning many watering program to many zones
assignDeviceTable - bridging table for assigning many devices to many watering zones.
Problem: I'm currently using the following query to try and join all of these tables together so that I can begin to control my Raspberry Pi with a multi-threaded Python script... I originally had this working as a nested SQL script (working dynamically in my Python script), but it got a little complex when trying to run multiple thread within a database results. Essentially I plan to take a number of key values from the SQL query and
There appears to be multiple rows being returned when there should only be one for each entry.. any idea of the best way to handle this? I've found a number of answers suggesting to use the DISTINCT option (which didn't work), although am I going about this the best way possible?
SELECT *
FROM deviceTable AS d, programTable AS p
JOIN assignDeviceTable AS ad ON d.deviceID = ad.deviceID
JOIN zoneTable AS z ON z.zoneID = a.zoneID
JOIN assignProgramTable AS a ON p.programID = a.programID
where p.programStatus = "1"
Following LS_dev's advice, I've updated the query to the following:
SELECT *
FROM deviceTable AS d, programTable AS p, assignDeviceTable AS ad, zoneTable AS z, assignProgramTable AS ap
JOIN deviceTable ON d.deviceID = ad.deviceID
JOIN assignDeviceTable ON ad.zoneID = z.zoneID
JOIN zoneTable ON z.zoneID = ap.zoneID
JOIN assignProgramTable ON ap.programID = p.programID
where p.programStatus = "1"
Unfortunately this resulted in even more rows being duplicated... still stuck!
In SQLite , is same as JOIN.
So, your query is same as shown below:
SELECT *
FROM deviceTable AS d
JOIN programTable AS p -- missing ON p.some_id=d.some_id
JOIN assignDeviceTable AS ad ON d.deviceID = ad.deviceID
JOIN zoneTable AS z ON z.zoneID = a.zoneID
JOIN assignProgramTable AS a ON p.programID = a.programID
where p.programStatus = "1"
You have 5 tables but just 3 join constraints. Normally Nconstraints = Ntables - 1.
Analysing your relations:
programTable p deviceTable d
/ \ / \
(p.programID=a.programID) (d.deviceID=ad.deviceID)
\ / \ /
assignProgramTable a assignDeviceTable ad
/ \
(z.zoneID=a.zoneID)
\ /
zoneTable z
is visible your missing a relation between those two groups. From your explanation I think it should be something like ad.zoneID = z.zoneID.
Related
I'm trying to perform the query below on SQL Server:
SELECT
[dbo].[Machine].[MachineID],
[dbo].[Machine].[CompanyID],
[dbo].[Company].[AccountRef],
[dbo].[Machine].[ProductTypeID],
[dbo].[Machine].[SerialNo],
[dbo].[Machine].[InstallationDate],
[dbo].[Machine].[SalesTypeID],
[dbo].[SalesType].[SalesType],
[dbo].[Machine].[LeasingCompanyID],
[dbo].[LeasingCompany].[Name],
[dbo].[Machine].[QuarterlyRentalCost],
[dbo].[Machine].[Term],
[dbo].[Machine].[ExpiryDate],
[dbo].[Machine].[Scales],
[dbo].[Machine].[Chips],
[dbo].[Machine].[ContractTypeID],
[dbo].[ContractType].[ContractType],
[dbo].[Machine].[ContractCost],
[dbo].[Machine].[InvoiceDate],
[dbo].[Machine].[ServiceDueDate],
[dbo].[Machine].[ServiceNotes],
[dbo].[Machine].[modelID],
[dbo].[Machine].[Model],
[dbo].[Machine].[IMP_Machine Reference],
[dbo].[Machine].[Smart]
FROM
[dbo].[Machine], [dbo].[Company], [dbo].[SalesType], [dbo].[LeasingCompany], [dbo].[ContractType]
LEFT JOIN
[dbo].[Machine] as A ON A.[CompanyID] = [dbo].[Company].[CompanyID]
LEFT JOIN
[dbo].[Machine] as B ON B.[SalesTypeID] = [dbo].[SalesType].[SalesTypeID]
LEFT JOIN
[dbo].[Machine] as C ON C.[LeasingCompanyID] = [dbo].[LeasingCompany].[LeasingCompanyID]
LEFT JOIN
[dbo].[Machine] as D ON D.[ContractTypeID] = [dbo].[ContractType].[ContractTypeID] ;
But for some reason that i cannot see for the life of me, the destination column name in the bottom 3 join statements is reporting "The multi part identifier could not be bound".
Could anyone assist please?
Many Thanks,
You were pretty close, for readability, you dont need the extensive [dbo].[table] all over. You can define it once in the from clause with an alias, then use that alias the rest of the way through. Also, make the alias make sense to the context of the table as you will see in this below. LeasingCompany lc, SalesType st, etc.
Also, I try to have indented so I always know the first table of the join relationship and the JOIN indented on where it is being joined to. Then I keep the orientation of the from/to table aliases the same context.
Since the machine table is used once and joined to 4 different lookup tables, you can reuse the same "m" alias to each underlying. Think of a tree and branches. The root tree is your "Machine", and all the branches are the lookups.
SELECT
m.MachineID,
m.CompanyID,
c.AccountRef,
m.ProductTypeID,
m.SerialNo,
m.InstallationDate,
m.SalesTypeID,
st.SalesType,
m.LeasingCompanyID,
lc.LeasingCompany.Name,
m.QuarterlyRentalCost,
m.Term,
m.ExpiryDate,
m.Scales,
m.Chips,
m.ContractTypeID,
ct.ContractType,
m.ContractCost,
m.InvoiceDate,
m.ServiceDueDate,
m.ServiceNotes,
m.modelID,
m.Model,
m.IMP_Machine Reference,
m.Smart
FROM
Machine m
LEFT JOIN Company c
ON m.CompanyID = c.CompanyID
LEFT JOIN SalesType st
ON m.SalesTypeID = st.SalesTypeID
LEFT JOIN LeasingCompany lc
ON m.LeasingCompanyID = lc.LeasingCompanyID
LEFT JOIN ContractType ct
ON m.ContractTypeID = ct.ContractTypeID ;
I am having a rows with two different IDs in database. Now I am trying to show two different data columns in one row, I tried something like this:
SELECT
[dbo].[fnHexToNumber]([Participant].[Stake]) AS [PlayerStake],
(SELECT [dbo].[fnHexToNumber]([Stake])
FROM [dbo].[Participant_Complete]
WHERE [ParticipantId] = [Fold].[HouseParticipantId]) AS [HouseStake],
([dbo].[fnHexToNumber]([Participant].[Stake]) + [dbo].[fnHexToNumber]([C].[RunningWinLoss])) AS [PlayerStakeAfterRound],
(SELECT [dbo].[fnHexToNumber]([Stake])
FROM [dbo].[Participant_Complete]
WHERE [ParticipantId] = [Fold].[HouseParticipantId]) - [dbo].[fnHexToNumber]([C].[RunningWinLoss]) AS [HouseStakeAfterRound]
FROM
[dbo].[Round_Complete] AS [C]
INNER JOIN
[dbo].[Fold_Complete] AS [Fold] ON [Fold].[Id] = [C].[Id]
INNER JOIN
[dbo].[Participant_Complete] AS [Participant] ON [Participant].[ParticipantId] = [Fold].[PlayerParticipantId]
This works, but as you can see it will do two trips to database for same nested select. How can I make this only one round trip?
You are referring to the subqueries. That is not a "round trip to the database", which usually refers to an application calling a query.
All the square braces make the query hard to read, but you can fix this using apply:
SELECT [dbo].[fnHexToNumber](p.[Stake]) AS PlayerStake,
h.HouseStake,
([dbo].[fnHexToNumber](p.[Stake]) + [dbo].[fnHexToNumber]([C].RunningWinLoss)) AS PlayerStakeAfterRound,
(h.HouseStake - [dbo].fnHexToNumber(C.RunningWinLoss)) AS HouseStakeAfterRound
FROM [dbo].[Round_Complete] c JOIN
[dbo].[Fold_Complete] f
ON f.[Id] = c.[Id] JOIN
[dbo].[Participant_Complete] pc
ON px.[ParticipantId] = f.[PlayerParticipantId] OUTER APPLY
(SELECT [dbo].[fnHexToNumber]([Stake]) as HouseStake
FROM [dbo].[Participant_Complete] pch
WHERE pch.ParticipantId = f.HouseParticipantId
) h
Just join the same table a second time instead of pulling the data as sub-queries.
Also, you only need brackets around names if the names contain a space (which is bad practice in general). If the names don't have a space, the brackets are totally extraneous.
SELECT
dbo.fnHexToNumber(Participant.Stake) AS PlayerStake,
dbo.fnHexToNumber(p.Stake) as HouseStake,
(dbo.fnHexToNumber(Participant.Stake) + dbo.fnHexToNumber(C.RunningWinLoss)) AS PlayerStakeAfterRound,
dbo.fnHexToNumber(p.Stake) - dbo.fnHexToNumber(c.RunningWinLoss) as HouseStakeAfterRound
FROM dbo.Round_Complete AS C
INNER JOIN dbo.Fold_Complete AS Fold
ON Fold.Id = C.Id
INNER JOIN dbo.Participant_Complete AS Participant
ON Participant.ParticipantId = Fold.PlayerParticipantId
INNER JOIN dbo.Participant_Complete AS p
ON p.ParticipantId = Fold.HouseParticipantId
I want to make a SQL query that will generate the following information, which is contained in eBS :
How would I go about doing this? I have been using eTRM to try and narrow down some of the columns, but I can't seem to figure out where to get the approved PO's and non-approved PO's. thanks
PO requisitions are linked to POs through distributions. That is,
po_requisition_distributions.distribution_id = po_distributions.req_distribution_id
That means, there is not necessarily a 1:1 relationship between requisition lines and purchase orders. So, you may need more than just two categories (linked to approved / linked to not-approved), depending on how you use eBS at your location.
Here is a query that links PO requisitions to POs that may get you started
SELECT porl.item_description,
hl.city,
poh.segment1 po#,
poh.authorization_status
FROM po_requisition_lines_all porl
INNER JOIN po_vendor_sites_all povs ON povs.vendor_site_id = porl.vendor_site_id
INNER JOIN hz_party_sites hps ON hps.party_site_id = povs.party_site_id
INNER JOIN hz_locations hl ON hl.location_id = hps.location_id
INNER JOIN po_req_distributions_all pord ON pord.requisition_line_id = porl.requisition_line_id
LEFT JOIN po_distributions_all pod ON pod.req_distribution_id = pord.distribution_id
LEFT JOIN po_headers_all poh ON poh.po_header_id = pod.po_header_id
WHERE porl.org_id = 321
AND hl.city IS NOT NULL
AND ROWNUM <= 10;
I have this code:
select Users.phoneMac, Users.apMac, Locations.Lon, Locations.Lat
from Locations, Users
inner join (
select u.phoneMac, max(u.strenght) as most
from Users u, Locations l
where u.apMac = l.apMac
group by u.phoneMac
) as ij on ij.phoneMac=Users.phoneMac and Users.strenght = ij.most
where Locations.apMac = Users.apMac;
It worked for me fine but when I added more data to users table this query calculated results from all the data and I wanted to get results just from latest data. So I added timestamp to Users table.
So can you help me fix this code so it first take only data from latest timestamp for every user(users.phoneMac)(there can be more then 1 row of data for same phoneMac) and then do the rest of calculations.
You're already picking the max value of the "strenght" field and joining on that, so why not use the same approach again for your timestamp field? Something like:
SELECT Users.phoneMac, Users.apMac, Locations.Lon, Locations.Lat
FROM Locations
INNER JOIN Users
ON Users.apMac = Locations.apMac
INNER JOIN (
SELECT u.phoneMac, max(u.strenght) AS most
FROM Locations l
INNER JOIN Users u ON u.apMac = l.apMac
GROUP BY u.phoneMac) AS ij
ON ij.phoneMac = Users.phoneMac
AND Users.strenght = ij.most
INNER JOIN (
SELECT u2.phoneMac, max(u2.timestampfield) AS latest
FROM Locations l2
INNER JOIN Users u2 ON u2.apMac = l2.apMac
GROUP BY u2.phoneMac) AS ijk
ON ijk.phoneMac = Users.phoneMac
AND Users.timestampfield = ij.latest;
(By the way, using the old join syntax with comma and the WHERE clause makes it harder to understand the logic, and occasionally makes the logic wrong. The new join syntax with ON is really a lot better.)
I know there are a lot of other SO entries that seem like this one, but I haven't found one that actually answers my question so hopefully one of you can either answer it or point me to another SO question that is related.
Basically, I have the following query that returns Venues that have any CheckIns that contain the searched Keyword ("foobar" in this example).
SELECT DISTINCT v.*
FROM "venues" v
INNER JOIN "check_ins" c ON c."venue_id" = v."id"
INNER JOIN "keywordings" ks ON ks."check_in_id" = c."id"
INNER JOIN "keywords" k ON ks."keyword_id" = k."id"
WHERE (k."name" = 'foobar')
I want to SELECT and ORDER BY the count of the matched Keyword for each given Venue. E.g. if there have been 5 CheckIns that have been created, associated with that Keyword, then there should be a returned column (called something like keyword_count) with the value 5 which is sorted.
Ideally this should be done without any queries in the SELECT clause, or preferably none at all.
I've been struggling with this for a while and my mind is just going blank (perhaps it's been too long a day) so some help would be greatly appreciated here.
Thanks in advance!
Sounds like you need something like:
SELECT v.x, v.y, count(*) AS keyword_count
FROM "venues" v
INNER JOIN "check_ins" c ON c."venue_id" = v."id"
INNER JOIN "keywordings" ks ON ks."check_in_id" = c."id"
INNER JOIN "keywords" k ON ks."keyword_id" = k."id"
WHERE (k."name" = 'foobar')
GROUP BY v.x, v.y
ORDER BY 3