I'm just starting out with SQL, I have been playing around with simple select queries and grouping data, now I want to pull some actually useful data out of our database for analysis. The data is organized as follows:
Access 2010 Database
I didn't set it up, I know it isn't set up as it should be
I can't change data, only poll
-Customers are kept in one table
-Closed orders are kept in another table (each line item is listed with invoice #, date closed, Customer ID as well as other info)
-Archived closed orders table keep sales records that are a year + old (table is laid out exactly the same as Closed order table)
I want to start with a simple query, list all the customers from a certain branch and their past year totals. Here's what I have tried:
SELECT CUSTOMERS.Company, CUSTOMERS.[Ship City], (SELECT SUM (CLOSEDORDERS.Quant*CLOSEDORDERS.SellPrice) FROM CLOSEDORDERS WHERE CUSTOMERS.ID = CLOSEDORDERS.CustID) AS LifeTotal
FROM CUSTOMERS, CLOSEDORDERS
WHERE CUSTOMERS.Branch=33;
When I run the query, it asks me to enter a parameter value for CLOSEDORDERS.Quant. What am I doing wrong?
I think this is what you're looking for with an OUTER JOIN:
SELECT CUSTOMERS.Company,
CUSTOMERS.[Ship City],
SUM(CLOSEDORDERS.Quant*CLOSEDORDERS.SellPrice) AS LifeTotal
FROM CUSTOMERS
LEFT JOIN CLOSEDORDERS ON CUSTOMERS.ID = CLOSEDORDERS.CustID
WHERE CUSTOMERS.Branch=33
GROUP BY CUSTOMERS.Company,
CUSTOMERS.[Ship City]
If you only want to return matching results from both tables, then use a standard INNER JOIN instead of the LEFT JOIN.
Related
I am new to sql and have a question about joining 2 tables. Why is there a . in between customers.custnum in this example. What is its significance and what does it do?
Ex.
Select
customers.custnum, state, qty
From
customers
Inner join
sales On customers.custnum = sales.custnum
The . is to specify a column of a table.
Let's use your customer table; we could do:
SELECT c.custnum, c.state, c.qty FROM customers as c INNER JOIN
sales as s ON c.custnum = s.custnum
You don't really need the . unless two tables have columns with the same name.
In the below query, there are two tables being referred. One is CUSTOMERS another is STATE. Since both has same column CUSTNUM, we need a way to tell the database which CUSTNUM are we referring to. Same as there may be many Bob's, if so their last name is used for disambiguation.
I would consider the below style as more clearer. That's opinionated.
Select
cust.custnum, cust.state, s.qty
From
customers cust -- use alias for meaningful referencing, you may be self-joining, during that time you can use cust1, cust2 as aliases.
Inner join
sales as s On cust.custnum = s.custnum
Think of it as a way to categorize the hierarchical nature of the database. Within a DB, there are tables, and within tables there are columns. It's just a way of keeping track, especially if you are working with multiple tables that may have the same column name.
For example, a table called Sales and a table called Customers might both have a column called Date. You may be writing a query where you only want the date from the Sales table, so you would specify that by writing:
Select *
From Sales
inner join Customers on Sales.ID = Customers.ID
where Sales.Date = '1/1/2019'
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I want to add a column to the query that calculates between These two columns In the same query ....................................................................
,isnull(sum(ORDERS.Net_Amount) + 0,0) as orders
,isnull(sum (convert(float,(RECEIPTS.Amount))) + 0,0) as recepts
IN SQL SERVER
SELECT CUSTOMERS.[ID_CUSTOMER]
,[FIRST_NAME]
,[TEL]
,[EMAIL]
,isnull(sum(ORDERS.Net_Amount) + 0,0) as orders
,isnull(sum (convert(float,(RECEIPTS.Amount))) + 0,0) as recepts
,[CRIDIT_LIMIT]
,[CUSTOMER_SINCE]
,[ADRESS]
,CUSTOMERS.[state]
FROM [CUSTOMERS]
LEFT JOIN ORDERS on CUSTOMERS.ID_CUSTOMER = ORDERS.CUSTOMER_ID
LEFT JOIN RECEIPTS on CUSTOMERS.ID_CUSTOMER = RECEIPTS.ID_CUSTOMER
GROUP BY CUSTOMERS.[ID_CUSTOMER]
,[FIRST_NAME]
,[TEL]
,[EMAIL]
,[CRIDIT_LIMIT]
,[CUSTOMER_SINCE]
,[ADRESS]
,CUSTOMERS.[state]
CUSTOMERS table
SELECT [ID_CUSTOMER]
,[FIRST_NAME]
,[TEL]
,[EMAIL]
,[IMAGE_CUSTOMER]
,[CRIDIT_LIMIT]
,[CUSTOMER_SINCE]
,[ADRESS]
,[Balance]
,[state]
FROM [CUSTOMERS]
ORDERS table
SELECT [ID_ORDER]
,[DATE_ORDER]
,[CUSTOMER_ID]
,[DESCRIPTION_ORDERS]
,[SALEMAN]
,[ORDER_TOTAL]
,[Discount_Of_Total]
,[Total_After_Discount]
,[Paid_Up]
,[Net_Amount]
,[state]
FROM [ORDERS]
RECEIPTS table
SELECT [image_state]
,[ID_RECEIPT]
,[ID_CUSTOMER]
,[Date]
,[Ref]
,[Amount]
,[Memo]
,[User_Name]
,[state]
,[Payment_Method]
,[Account_ID]
FROM [RECEIPTS]
Orders and receipts are not really related to each other (the receipt doesn't refer to a specific order), so don't join the two. What you want to do instead is find the order amount and the receipt amount per customer and show them. So aggregate the two tables per customer and outer-join the results to the customer table.
select
c.id_customer,
c.first_name,
c.tel,
c.email,
coalesce(o.sum_net_amount, 0) as order_amount,
coalesce(r.sum_amount, 0) as receipt_amount,
c.cridit_limit,
c.customer_since,
c.adress,
c.balance,
c.state
from customers c
left join
(
select customer_id, sum(net_amount) as sum_net_amount
from orders
group by customer_id
) o on c.id_customer = o.customer_id
left join
(
select id_customer, sum(amount) as sum_amount
from receipts
group by id_customer
) r on c.id_customer = r.id_customer;
I see you have updated your request now asking also for the difference of the sums. Well, the operator for subtraction in SQL is - little surprising - the minus sign:
coalesce(o.sum_net_amount, 0) - coalesce(r.sum_amount, 0) as diff
Please try the following...
SELECT Customers.ID_Customer,
first_name,
tel,
email,
SUM( net_amount ) AS OrdersTotal,
COALESCE( sumAmount, 0 ) AS PaymentsTotal,
SUM( net_amount ) - COALESCE( sumAmount, 0 ) AS DifferenceInTotals,
cridit_limit,
customer_since,
adress,
balance,
state
FROM Customers
INNER JOIN Orders ON Customers.ID_Customer = Orders.Customer_ID
LEFT JOIN ( SELECT ID_Customer,
SUM( amount ) AS sumAmount
FROM Receipts
GROUP BY ID_Customer
) AS sumAmountFinder ON Customers.ID_Customer = sumAmountFinder.ID_Customer
GROUP BY Customers.ID_Customer,
first_name,
tel,
email,
cridit_limit,
customer_since,
adress,
balance,
state;
This Answer is based on the assumption that every Customer will have at least one Order, but possibly no Receipts.
This statement is essentially the one that you supplied with the following modifications...
I have changed the JOIN to Orders to an INNER JOIN, since I am assuming that each Customer will have at least one Order. The LEFT JOIN is only necessary where you wish to retain all records from the left table that do not have at least one matching record from the right table as defined by the ON clause. (Note : If you wish to retain all the records from the right table where there is no matching records from the left table, use a RIGHT JOIN).
I have replaced the JOIN to the Receipts table with a subquery that calculates the total of the amount field for each Customer in the Receipts table. A LEFT JOIN is necessary between Customers and the results of this subquery as not all Customers will have a Receipt. In such situations the LEFT JOIN will set each of the fields from the subquery in the joined dataset to NULL.
Where the SUM() function encounters only NULL values it returns NULL, not 0. So that PaymentsTotal will be set to 0 for records where the Customer has no Receipts, I have used the COALESCE() function. This function will return the first non-NULL argument it encounters. Here I have set it to return the total of amount where it encounters one, and 0 where it encounters no total amount.
I have removed all of the square brackets from your field and table names. They are only required where you have used an otherwise disallowed name, such as names with spaces (use [Full Name] instead of Full Name) or names that are also reserved by SQL-Server (if you had decided to call PaymentsTotal Sum, then you would have had to use AS [Sum]). Many programmers consider giving fields such names to be bad practice, even when it is possible with []'s, but fortunately you have not used any otherwise names.
I have removed the table names from your SUM() calculations. Since only one table has a field called net_amount, then it will be a unique field name in the joined dataset, and you will be able to refer to them without specifying the name of the source table as well. Specifying the source table is still necessary in the case of Customers.ID_Customer as the joined dataset will have more than one field called ID_Customer. Also, you will need to specify the source tables names when creating the joined dataset using the JOIN's.
I have also taken the liberty of changing your capitalisation scheme. Having just about everything in constant upper-case is monotonous to the eye. Using different casing for SQL terms, table names and field names makes recognising each type of statement part much easier, and thus makes debugging code much easier.
Finally, and relatively trivially, cridit is actually spelt credit and adress is actually spelt address.
If you have any questions or comments, then please feel free to post a Comment accordingly.
beginner sql coder. I have an Access database with a customers table and orders table. The headers of the columns have a space (i.e: Shipped Date). I need to return Company Name, Contact Name, and Phone of customers who placed orders in March of 1998. Shipped Dates are formatted as 01-Mar-1998.
How do I do this? Access keeps giving me errors
SELECT Orders.*,Customers.CompanyName, Customers.ContactName, Customers.Phone
FROM Customers, Orders
(SELECT *
FROM Orders
JOIN Customers ON Orders.Order ID=Customers.Order ID)
AND Shipped Date BETWEEN #03/01/1998# AND #03/31/1998#;
GROUP BY Customers.CompanyName, Customers.ContactName, Customers.Phone;
EDIT:
New code
SELECT *
FROM Orders INNER JOIN Customers ON Orders.Customer=Customers.[Company Name]
WHERE Orders.[Shipped Date] BETWEEN #01-MAR-1998# AND #31-MAR-1998#;
The code runs, but Access prompts me to enter values for the all of the column names...Please help!
Your Query is incorrectly formed. As we should enclose the coloumns with names containing spaces in []
also tour GROUP BY was not relevant.
Now when we use JOIN we should have the query like :
SELECT * FROM Orders JOIN Customers ON Orders.[Order ID]=Customers.[Order ID]
WHERE Orders.[Shipped Date] BETWEEN #03/01/1998# AND #03/31/1998#;
I'm not sure if what I want to do is possible but if it is possible, it's probably a really easy solution that I just can't figure out. Once things get to a certain complexity though, my head starts spinning. Please forgive my ignorance.
I have a database running in MS Access 2007 for a school which has a plethora of tables joined to each other. I'm trying to create a query in which I get information from several tables. I'm looking up sales and payment information for different customers, pulling info from several different linked tables. Each sale is broken down into one of 4 categories, Course Fee, Registration Fee, Book Fee and Others. Because each customer will have multiple purchases, each one is a separate entry in the Sales table. The payment information is also in its own table.
My SQL currently looks like this:
SELECT StudentContracts.CustomerID, (Customers.CFirstName & " " & Customers.CLastName) AS Name, Customers.Nationality, Courses.CourseTitle, (StudentContracts.ClassesBought + StudentContracts.GiftClasses) AS Weeks, StudentContracts.StartDate, Sales.SaleAmount, SaleType.SaleType, Sales.DueDate, Payments.PaymentAmount
FROM (
(
(Customers INNER JOIN StudentContracts ON Customers.CustomerID = StudentContracts.CustomerID)
INNER JOIN Payments ON Customers.CustomerID = Payments.CustomerID)
INNER JOIN
(SaleType INNER JOIN Sales ON SaleType.SalesForID = Sales.SalesForID)
ON Customers.CustomerID = Sales.CustomerID)
INNER JOIN
(
(Courses INNER JOIN Classes ON Courses.CourseID = Classes.CourseID)
INNER JOIN StudentsClasses ON Classes.ClassID = StudentsClasses.ClassID)
ON Customers.CustomerID = StudentsClasses.CustomerID;
This works and brings up the information I need. However, I am getting one record for each sale as in:
CustomerID Name ... SaleAmount SaleType PaymentAmount
1 Bob $600 Course $1000
1 Bob $300 RgnFee $1000
1 Bob $100 Book $1000
What I need is one line for each customer but each sale type in it's own column in the row with the sale amount listed in its value field. As so:
CustomerID Name ... Course RgnFee Book Others PaymentAmount
1 Bob $600 $300 $100 $1000
Can anyone help and possibly explain what I should/need to be doing?
Thanks in advance!
You can create a cross tab from the query you have already created. Add the query to the Query Design Grid, choose Crosstab from query types, and select a Row or rows, Column and Value.
Say:
TRANSFORM Sum(t.SaleAmount) AS SumOfSaleAmount
SELECT t.ID, t.Name, Sum(t.SaleAmount) AS Total
FROM TableQuery t
GROUP BY t.ID, t.Name
PIVOT t.SaleType
If you want a certain order, you can edit the property sheet to include column headings, or you can add an In statement to the SQL. Note that if you add column headings, a column will be included for each column, whether or not data is available, and more importantly, a column will not be included that has data, if it is not listed.
TRANSFORM Sum(t.SaleAmount) AS SumOfSaleAmount
SELECT t.ID, t.Name, Sum(t.SaleAmount) AS Total
FROM TableQuery t
GROUP BY t.ID, t.Name
PIVOT t.SaleType In ("Course","RgnFee","Book","Others");
i have a complex query to be written but cannot figure it out
here are my tables
Sales --one row for each sale made in the system
SaleProducts --one row for each line in the invoice (similar to OrderDetails in NW)
Deals --a list of possible deals/offers that a sale may be entitled to
DealProducts --a list of quantities of products that must be purchased in order to get a deal
now im trying to make a query which will tell me for each sale which deals he may get
the relevant fields are:
Sales: SaleID (PK)
SaleProducts: SaleID (FK), ProductID (FK)
Deals: DealID (PK)
DealProducts: DealID(FK), ProductID(FK), Mandatories (int) for required qty
i believe that i should be able to use some sort of cross join or outer join, but it aint working
here is one sample (of about 30 things i tried)
SELECT DealProducts.DealID, DealProducts.ProductID, DealProducts.Mandatories,
viwSaleProductCount.SaleID, viwSaleProductCount.ProductCount
FROM DealProducts
LEFT OUTER JOIN viwSaleProductCount
ON DealProducts.ProductID = viwSaleProductCount.ProductID
GROUP BY DealProducts.DealID, DealProducts.ProductID, DealProducts.Mandatories,
viwSaleProductCount.SaleID, viwSaleProductCount.ProductCount
The problem is that it doesn't show any product deals that are not fulfilled (probably because of the ProductID join). i need that also sales that don't have the requirements show up, then I can filter out any SaleID that exists in this query where AmountBought < Mandatories etc
Thank you for your help
I'm not sure how well I follow your question (where does viwSaleProductCount fit in?) but it sounds like you will want an outer join to a subquery that returns a list of deals along with their associated products. I think it would go something like this:
Select *
From Sales s Inner Join SaleProducts sp on s.SaleID = sp.SaleID
Left Join (
Select *
From Deals d Inner Join DealProducts dp on d.DealID = dp.DealId
) as sub on sp.ProductID = sub.ProductID
You may need to add logic to ensure that deals don't appear twice, and of course replace * with the specific column names you'd need in all cases.
edit: if you don't actually need any information from the sale or deal tables, something like this could be used:
Select sp.SaleID, sp.ProductID, sp.ProductCount, dp.DealID, dp.Mandatories
From SaleProducts sp
Left Join DealProducts as dp on sp.ProductID = dp.ProductID
If you need to do grouping/aggregation on this result you will need to be careful to ensure that deals aren't counted multiple times for a given sale (Count Distinct may be appropriate, depending on your grouping). Because it is a Left Join, you don't need to worry about excluding sales that don't have a match in DealProducts.