I currently have three tables.
master_tradesmen
trades
master_tradesmen_trades (joins the previous two together in a many-to-many relationship). The 'trade_id' and 'master_tradesman_id' are the foreign keys.
Here is what I need to happen. A user performs a search and types in a trade. I need a query that displays all of the information from the master_tradesmen table whose trade in the master_tradesmen_trade table matches the search. For example, if 'plumbing' is typed in the search bar (trade_id 1), all of the columns for Steve Albertsen (master_tradesman_id 6) and Brian Terry (master_tradesman_id 8) would be displayed from the master_tradesmen table. As a beginner to SQL, trying to grasp the logic of this is about to make my head explode. I'm hoping that someone with more advanced SQL knowledge can wrap their head around this much easier than I can. Note: the 'trades' column in master_tradesmen is for display purposes only, not for querying. Thank you so much in advance!
You have a catalog for the tradesmen, & another catalog for the trades.
The trades should only appear once in the trades catalog in order to make your DB more consistent
Then you have your many-to-many table which connects the trades & master tradesmen tables.
If we want to get the tradesmen according to the given trade in the input, we should first
know the id of that trade which has to be unique, so in your DB you would have something
like the img. below :
Now we can make a query to select the id of trade :
DECLARE #id_trade int = SELECT trade_id FROM trades WHERE trade_name LIKE '%plumbing%'
Once we know the trading id, we can redirect to the 'master_tradesmen_trades' table to know the name of the people how work that trade :
SELECT * FROM master_tradesmen_trades WHERE trade_id = #id_trade
You will get the following result :
You may say, 'But there is still something wrong with it, as i am still not able to see the tradesmen', this is the moment when we make an inner join:
SELECT * FROM master_tradesmen_trades trades_and_tradesmen
INNER JOIN master_tradesman tradesmen
ON tradesmen.id = trades_and_tradesmen.master_tradesmen_id
WHERE trade_id = #id_trade
IF you need to see specific columns, you can do :
SELECT first_name, last_name, city, state FROM master_tradesmen_trades trades_and_tradesmen
INNER JOIN master_tradesman tradesmen
ON tradesmen.id = trades_and_tradesmen.master_tradesmen_id
WHERE trade_id = #id_trade
I'm working in a large access database (Access 2010) and am trying to return records where two locations are different.
In my case, I have a large number of birds that have been observed on multiple dates and potentially on different islands. Each bird has a unique BirdID and also an actual physical identifier (unfortunately that may have changed over time). [I'm going to try addressing the changing physical identifier issue later]. I currently want to query individual birds where one or more of their observations is different than the "IslandAlpha" (the first island where they were observed). Something along the lines of a criteria for BirdID: WHERE IslandID [doesn't equal] IslandAlpha.
I then need a separate query to find where all observations DO equal where they were first observed. So where IslandID = IslandAlpha
I'm new to Access, so let me know if you need more information on how my tables/relationships are set up! Thanks in advance.
Assuming the following tables:
Birds table in which all individual birds have records with a unique BirdID and IslandAlpha.
Sightings table in which individual sightings are recorded, including IslandID.
Your first query would look something like this:
SELECT *
FROM Birds
INNER JOIN Sightings ON Birds.BirdID=Sightings.BirdID
WHERE Sightings.IslandID <> Birds.IslandAlpha
You second query would be the same but with = instead of <> in the WHERE clause.
Please provide us information about the tables and columns you are using.
I will presume you are asking this question because a simple join of tables and filtering where IslandAlpha <> ObsLoc is not possible because IslandAlpha is derived from first observation record for each bird. Pulling first observation record for each bird requires a nested query. Need a unique record identifier in Observations - autonumber should serve. Assuming there is an observation date/time field, consider:
SELECT * FROM Observations WHERE ObsID IN
(SELECT TOP 1 ObsID FROM Observations AS Dupe
WHERE Dupe.ObsBirdID = Observations.ObsBirdID ORDER BY Dupe.ObsDateTime);
Now use that query for subsequent queries.
SELECT * FROM Observations
INNER JOIN Query1 ON Observations.ObsBirdID = Query1.ObsBirdID
WHERE Observations.ObsLocID <> Query1.ObsLocID;
this is my first question on here, so please forgive me if I break any rules.
Here is what I need to know:
How do I create an Oracle SQL query that will display a unique count of something even if there are duplicates in the results?
Example: a customer table has a list of purchases made by various customers. The table lists the customer ID, name, category of purchase (ie Hardware, Tools, Seasonal) ect. The outcome of the query needs to show each customer id, customer name and the category of the purchase, and a count of the individual customer. SO customer ID 1 for John Smith has made a purchase in each department. If I do a count of the customer, he will appear three times as he has made three purchases, but I also need a column to count the customer only once. The count in the other rows returned for the other departments should show a 0 or Null.
I normally achieve this by pulling everything and exporting to excel. I add a column that uses an IF formula on the ID to only show a 1 on the first occurrence of the customer IE: IF(A3=A2,0,1) (if a3 is the same as A2, show a 0, if it's not the same as A2 then show a 1). This will give me a unique count of customers for one part of the report and will still show me how many purchase the customer made in another part of the report.
I want to do this directly in the SQL query as I have a large set of data this needs to be done on, and adding any formulas in excel will make the sheet huge. This will also make it easier to host the query results in ACCESS so excel can pull it from there.
I have tried to find a solution to this for a while, but any searching on Google will usually return results on how to remove duplicates form a table or how to count the duplicates in a table.
I am sorry if this is long question, but I wanted to be through so I do not waste anyone's time on back an fourth comments (I have seen this many times on here and else where when the OP asks a very cryptic question and expects everyone to understand them without further expiation).
Using distinct can be used in a count to only count the unique values of a field.
SELECT
cust.customer_id, cust.customer_name, p.category,
count(distinct p.department_id) as total_departments,
count(*) as total_purchases
FROM customers cust
LEFT JOIN purchase_table p on (cust.customer_id = p.customer_id)
GROUP BY cust.customer_id, cust.customer_name, p.category
ORDER BY cust.customer_id;
Such method is not limited to the Oracle RDBMS.
I'm currently working on a program that keeps track of my company's stock inventory, using ms Access 2010. I'm having a hard time getting the query, intended to show inventory, to display the information I want. The problem seems to be that the query pulls the same record multiple times, inflating the sums of reserved and sold product.
Background:
My company stocks steel bars. We offer to cut the bars into pieces. From an inventory side, We want to track the length of each bar, from the moment it comes in to the warehouse, through it's time in the warehouse (where it might get cut into smaller pieces), until the entire bar is sold and gone.
Database:
The query giving problems, is consulting 3 tables;
Barstock (with the following fields)
BatchNumber (all the bars recieved, beloning to the same production heat)
BarNo (the individual bar)
Orginial Length (the length of the bar when recieved at the stock
(BatchNumber and BarNo combined, is the primary key)
Sales
ID (primary key)
BatchNumber
BarNo
Quantity Sold
Reservation (a seller kan reserve some material, when a customer signals interest, but needs time to decide)
ID (Primary key)
BatchNumber
BarNo
Quantity reserved
I'd like to pull information from the three tables into one list, that displays:
-Barstock.orginial length As Received
- Sales.Quantity sold As Sold
- Recieved - Sold As On Stock
- reservation.Quantity Reserved As Reserved
- On Stock - Reserved As Available.
The problem is that I suck at sql. I've looked into union and inner join to the best of my ability, but my efforts have been in vain. I usually rely on the design view to produce the Sql statements I need. With design view, I've come up with the following Sql:
SELECT
BarStock.BatchNo
, BarStock.BarNo
, First(BarStock.OrgLength) AS Recieved
, Sum(Sales.QtySold) AS SumAvQtySold
, [Recieved]-[SumAvQtySold] AS [On Stock]
, Sum(Reservation.QtyReserved) AS Reserved
, ([On Stock]-[Reserved])*[Skjemaer]![Inventory]![unitvalg] AS Available
FROM
(BarStock
INNER JOIN Reservation ON (BarStock.BarNo = Reservation.BarNo) AND (BarStock.BatchNo = Reservation.BatchNo)
)
INNER JOIN Sales ON (BarStock.BarNo = Sales.BarNo) AND (BarStock.BatchNo = Sales.BatchNo)
GROUP BY
BarStock.BatchNo
, BarStock.BarNo
I know that the query is pulling the same record multiple times because;
- when I remove the GROUP BY term, I get several records that are exactley the same.
- There are however, only one instance of these records in the corresponding tables.
I hope I've been able to explain myself properly, please ask if I need to elaborate on anything.
Thank you for taking the time to look at my problem!
!!! Checking some assumptions
From your database schema, it seems that:
There could be multiple Sales records for a given BatchNumber/BarNo (for instance, I can imagine that multiple customers may have bought subsections of the same bar).
There could be multiple Reservation records for a given BatchNumber/BarNo (for instance, multiple sections of the same bar could be 'reserved')
To check if you do indeed have multiple records in those tables, try something like:
SELECT CountOfDuplicates
FROM (SELECT COUNT(*) AS CountOfDuplicates
FROM Sales
GROUP BY BatchNumber & "," & BarNo)
WHERE CountOfDuplicates > 1
If the query returns some records, then there are duplicates and it's probably why your query is returning incorrect values.
Starting from scratch
Now, the trick to your make your query work is to really think about what is the main data you want to show, and start from that:
You basically want a list of all bars in the stock.
Some of these bars may have been sold, or they may be reserved, but if they are not, you should show the Quantity available in Stock. Your current query would never show you that.
For each bar in stock, you want to list the quantity sold and the quantity reserved, and combined them to find out the quantity remaining available.
So it's clear, your central data is the list of bars in stock.
Rather than try to pull everything into a single large query straight away, it's best to create simple queries for each of those goals and make sure we get the proper data in each case.
Just the Bars
From what you explain, each individual bar is recorded in the BarStock table.
As I said in my comment, from what I understand, all bars that are delivered have a single record in the BarStock table, without duplicates. So your main list against which your inventory should be measured is the BarStock table:
SELECT BatchNumber,
BarNo,
OrgLength
FROM BarStock
Just the Sales
Again, this should be pretty straightforward: we just need to find out how much total length was sold for each BatchNumber/BarNo pair:
SELECT BatchNumber,
BarNo,
Sum(QtySold) AS SumAvQtySold
FROM Sales
GROUP BY BatchNumber, BarNo
Just the Reservations
Same as for Sales:
SELECT BatchNumber,
BarNo,
SUM(QtyReserved) AS Reserved
FROM Reservation
GROUP BY BatchNumber, BarNo
Original Stock against Sales
Now, we should be able to combine the first 2 queries into one. I'm not trying to optimise, just to make the data work together:
SELECT BarStock.BatchNumber,
BarStock.BarNo,
BarStock.OrgLength,
S.SumAvQtySold,
(BarStock.OrgLength - Nz(S.SumAvQtySold)) AS OnStock
FROM BarStock
LEFT JOIN (SELECT BatchNumber,
BarNo,
Sum(QtySold) AS SumAvQtySold
FROM Sales
GROUP BY BatchNumber, BarNo) AS S
ON (BarStock.BatchNumber = S.BatchNumber) AND (BarStock.BarNo = S.BarNo)
We do a LEFT JOIN because there might be bars in stock that have not yet been sold.
If we did an INNER JOIN, we wold have missed these in the final report, leading us to believe that these bars were never there in the first place.
All together
We can now wrap the whole query in another LEFT JOIN against the reserved bars to get our final result:
SELECT BS.BatchNumber,
BS.BarNo,
BS.OrgLength,
BS.SumAvQtySold,
BS.OnStock,
R.Reserved,
(OnStock - Nz(Reserved)) AS Available
FROM (SELECT BarStock.BatchNumber,
BarStock.BarNo,
BarStock.OrgLength,
S.SumAvQtySold,
(BarStock.OrgLength - Nz(S.SumAvQtySold)) AS OnStock
FROM BarStock
LEFT JOIN (SELECT BatchNumber,
BarNo,
SUM(QtySold) AS SumAvQtySold
FROM Sales
GROUP BY BatchNumber,
BarNo) AS S
ON (BarStock.BatchNumber = S.BatchNumber) AND (BarStock.BarNo = S.BarNo)) AS BS
LEFT JOIN (SELECT BatchNumber,
BarNo,
SUM(QtyReserved) AS Reserved
FROM Reservation
GROUP BY BatchNumber,
BarNo) AS R
ON (BS.BatchNumber = R.BatchNumber) AND (BS.BarNo = R.BarNo)
Note the use of Nz() for items that are on the right side of the join: if there is no Sales or Reservation data for a given BatchNumber/BarNo pair, the values for SumAvQtySold and Reserved will be Null and will render OnStock and Available null as well, regardless of the actual quantity in stock, which would not be the result we expect.
Using the Query designer in Access, you would have had to create the 3 queries separately and then combine them.
Note though that the Query Designed isn't very good at dealing with multiple LEFT and RIGHT joins, so I don't think you could have written the whole thing in one go.
Some comments
I believe you should read the information that #Remou gave you in his comments.
To me, there are some unfortunate design choices for this database: getting basic stock data should be as easy as s simple SUM() on the column that hold inventory records.
Usually, a simple way to track inventory is to keep track of each stock transaction:
Incoming stock records have a + Quantity
Outgoing stock records have a - Quantity
The record should also keep track of the part/item/bar reference (or ID), the date and time of the transaction, and -if you want to manage multiple warehouses- which warehouse ID is involved.
So if you need to know the complete stock at hand for all items, all you need to do is something like:
SELECT BarID,
Sum(Quantity)
FROM StockTransaction
GROUP BY BarID
In your case, while BatchNumber/BarNo is your natural key, keeping them in a separate Bar table would have some advantages:
You can use Bar.ID to get back the Bar.BatchNumber and Bar.BarNo anywhere you need it.
You can use BarID as a foreign key in your BarStock, Sales and Reservation tables. It makes joins easier without having to mess with the complexities of compound keys.
There are things that Access allows that are not really good practice, such as spaces in table names and fields, which end up making things less readable (at least because you need to keep them between []), less consistent with VBA variable names that represent these fields, and incompatible with other database that don't accept anything other than alphanumerical characters for table and field names (should you wish to up-size later or interface your database with other apps).
Also, help yourself by sticking to a single naming convention, and keep it consistent:
Do not mix upper and lower case inconsistently: either use CamelCase, or lower case or UPPER case for everything, but always keep to that rule.
Name tables in the singular -or the plural-, but stay consistent. I prefer to use the singular, like table Part instead of Parts, but it's just a convention (that has its own reasons).
Spell correctly: it's Received not Recieved. That mistake alone may cost you when debugging why some query or VBA code doesn't work, just because someone made a typo.
Each table should/must have an ID column. Usually, this will be an auto-increment that guarantees uniqueness of each record in the table. If you keep that convention, then foreign keys become easy to guess and to read and you never have to worry about some business requirement changing the fact that you could suddenly find yourself with 2 identical BatchNumbers, for some reason you can't fathom right now.
There are lots of debates about database design, but there are certain 'rules' that everyone agrees with, so my recommendation should be to strive for:
Simplicity: make sure that each table records one kind of data, and does not contain redundant data from other tables (normalisation).
Consistency: naming conventions are important. Whatever you choose, stick to it throughout your project.
Clarity: make sure that you-in-3-years and other people can easily read the table names and fields and understand what they are without having to read a 300 page specification. It's not always possible to be that clear, but it's something to strive for.
I need to find the sum of the prices of a number of products, however the prices are stored in a different table to products that need pricing.
But, there is a catch, it needs to select these items based on criteria from a third table too.
So, I need the sum of the price of all products in Table 1 where CutID in Table 2 = 001.
Table 1 and Table 2 are linked on SCID, one to many respectively.
If this makes no sense tell me and I will try to clarify?
Thanks,
Bob P
Based on your question, I don't think there's a need for VBA. Excel formulas should be sufficient.
Add a few columns to your primary table. In these columns, use vlookup() to get all your information in one place, including the criteria.
If you only need to sum based on one criteria, use sumif(). If there's multiple criteria, use sumproduct().
Generally, with Access, I initially try to work with something as close a possible to a standard SQL query for ease of maintenance and portability. This ran for me in Access 2010:
SELECT Products.ProductID, Sum(Prices.Price) AS PriceSum
FROM Prices INNER JOIN (Critera INNER JOIN Products ON Critera.SCID = Products.SCID) ON Prices.ProductID = Products.ProductID
WHERE Critera.CutID="001"
GROUP BY Products.ProductID;
Please let us know if that works with your data (I'm not sure of your column names, either).