I want to see what customers ordered what from a given manufacture.
I have theses tables (with columns):
items (item_num, order_num, stock_num, manu_code, quantity, etc.)
stock (stock_num, manu_code, description, unit_price, etc.)
orders (order_num, order_date, customer_num, ship_instruct, etc.)
customer (customer_num, fname, lname, company, address1, etc.)
This is my query right now, but I believe it is returning a cross product of some sort:
SELECT concat(c.fname," ", c.lname) AS fullname, s.description
FROM items i, stock s, customer c JOIN orders o
ON o.customer_num=c.customer_num
WHERE o.order_num=i.order_num AND i.manu_code = 'ANZ';
Which returns a big list (1000 lines) with lots of duplicate entires,
Anthony Higgens | baseball gloves
Anthony Higgens | baseball gloves
. .
. .
. .
Kim Satifer | running shoes
What am I doing wrong?
FROM items i, stock s, customer c does a cartesian join of those three tables involved, but your WHERE does very little restriction on that cartesian join.
If you do some more explicit joining you will grealy cut down on duplicates and more properly express what you are trying to do. Use INNER JOINS and the correct join criteria instead of just listing all the tables after the FROM. Example: (there are more such criteria, you would need to apply to the JOINS, but this is one example): INNER JOIN stock ON stack.manu_code = items.manu_code.
Finally, you can use SELECT DISTINCT or GROUP BY to further reduce duplicates. But if you get your explicit JOINs with JOIN criteria right, you should not have too many duplicates.
Try this:
SELECT DISTINCT concat(c.fname," ", c.lname) AS fullname, s.description
FROM customer c
INNER JOIN orders o ON c.customer_num = o.customer_num
INNER JOIN items i ON o.order_num = i.order_num
INNER JOIN stock s on s.stock_num = i.stock_num
WHERE i.manu_code = 'ANZ'
This should work :
SELECT concat(a.fname, " ", a.lname ) as name
, d.description as desc
FROM CUSTOMER a
INNER JOIN ORDERS b
on a.customer_num = b.customer_num
INNER JOIN ITEMS c
on b.order_num = c.order_num
INNER JOIN STOCK d
on c.manu_code = d.manu_code
where c.manu_code like 'ANZ'
group by name,desc
Thanks everybody, I think this is working now:
SELECT DISTINCT concat(c.fname," ", c.lname) AS fullname, s.description
FROM customer c
INNER JOIN orders o ON c.customer_num = o.customer_num
INNER JOIN items i ON o.order_num = i.order_num
INNER JOIN stock s on s.stock_num = i.stock_num
WHERE i.manu_code = 'ANZ';
Related
I have two MySQL-tables:
Persons (pid,name,companyID,companyName)
Orders (oid,companyID,details)
Now I want to count the number of order_id for each companyName as following:
Name Total
-------------------
CompanyName1 : 1200
CompanyName2 : 758
CompanyName3 : 11
I used this query but it's not working properly.
SELECT count(o.oid) as total,p.companyName
FROM orders as o, persons as p
WHERE o.companyID = p.companyID
GROUP BY p.companyName
Use join and group the result by p.companyID
SELECT p.companyName, count(o.oid) as total
FROM orders as o join persons as p
on o.companyID = p.companyID
GROUP BY p.companyID
If you are missing the companies without any orders you can use a left join.
SELECT p.companyName, count(*) as total
FROM persons p
LEFT JOIN orders o ON o.companyID = p.companyID
GROUP BY p.companyID, p.companyName
Please do not use the old, legacy join syntax any more - it is outdated since 1992.
Your data model looks messed up. That you have company ids and names in the person table but no corresponding companies table is highly suspicious.
In any case, presumably there can be multiple rows per company. You can condense the persons table and then join:
SELECT c.companyName, COUNT(*) as total
FROM orders o JOIN
(SELECT DISTINCT companyId, companyName
FROM persons p
) c
ON o.companyID = c.companyID
GROUP BY c.companyName;
However, you should fix the data model so you have a real bona fide companies table -- especially because you seem to care about that entity.
I am having trouble to answer this question :
Display the last name and client company (COMPANY) for the employees who made a sale for clients of Paris" sorted on the Company Name.
Here is my code :
select NAME from EMPLOYEES inner join SALES on EMPLOYEES.NO_EMPLOYEES = SALE.NO_EMPLOYEES
union
select COMPANY from SALES inner join CLIENTS on SALES.CODE_CLIENT = CLIENTS.CODE_CLIENT where CLIENTS.CITY = 'Paris'
Problem is that union gives me only one column... How to solve this issue ?
Thanks for your help !
I think you just want two joins:
select e.NAME, c.COMPANY
from EMPLOYEES e join
SALES s
on e.NO_EMPLOYEES = s.NO_EMPLOYEES join
CLIENTS c
on s.CODE_CLIENT = c.CODE_CLIENT
where c.CITY = 'Paris';
I'm trying to get the the students number & name with the course code & name for students who have a grade below 40. This is what i have
SELECT S.name, S.no, C.code, C.name, T.grade
FROM student S INNER JOIN course C INNER JOIN take T
WHERE grade <40;
It is outputting the grades under 40 but it is returning 128 rows showing everyone's name and number grade repeating them.
Sorry if this is wrong but im a beginner.
You need the conditions that relate the tables to each other:
SELECT S.name, S.no, C.code, C.name, T.grade
FROM student AS s
JOIN take AS t ON t.student_no = s.no
JOIN course AS c ON t.course_code = c.code
Replace student_no and course_code with the actual foreign key columns in the take table.
Simple syntax refer it
SELECT Orders.OrderID, Customers.CustomerName, Shippers.ShipperName
FROM ((Orders
INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID)
INNER JOIN Shippers ON Orders.ShipperID = Shippers.ShipperID);
I'm trying understand how I can pull information from multiple tables at once in one query if that is possible.
I have 3 tables and I'm wondering if there is a way I can query all the product names for customers that live in california?
Table:
products
Fields:
productOid
productName
companyOid
Table:
customerData
Fields:
customerOid
firstName
lastName
state
Table:
orders
Fields:
orderNumber
customerOid
productOid
Would this fall under something like an INNER JOIN?
Also, I'm learning mySQL.
You will need to use inner joins for this.
SELECT DISTINCT p.productName
FROM orders o
INNER JOIN customerData c ON o.customerOid = c.customerOid
INNER JOIN products p ON o.productOid = p.productOid
WHERE c.state = 'CA';
I am using DISTINCT here because it's possible a customer would order the same product more than once (or multiple customers would order the same products) and I'm assuming you don't want duplicates.
I'm also making the assumption that your state is represented as a two character column.
Read more about joins
You could use one more join, but I would write it this way:
SELECT DISTINCT p.productName
FROM
orders o INNER JOIN products p
ON o.productOid = p.productOid
WHERE
o.customerOid IN (SELECT customerOid
FROM customerData
WHERE state = 'California')
It might be a little slover than a join, but it's more readable.
This shows products that CA customers have ordered:
SELECT p.productName
FROM orders o
INNER JOIN products p ON o.productOid = p.productOid
INNER JOIN customerData c ON o.customerOid = c.customerOid
WHERE c.state = 'CA'
I have a pretty simple MySQL question. I have two tables, Customer and Orders. Customer table has fields (id, name) and Order has fields (id, customerID, and item).
I can find which customer bought product A and customers that bought product B with the following query in MySQL.
SELECT DISTINCT c.`id`, c.name, o.`item`, o.qty FROM `customer` as c
INNER JOIN order AS o ON (c.`Id` = o.`customerID`)
where o.`item` ="Product A"
Union
SELECT DISTINCT c.`id`, c.name, o.`item`, o.qty FROM `customer` as c
INNER JOIN order AS o ON (c.`Id` = o.`customerID`)
where o.`item` ="Product B"
How can find the difference and similarity in these two result sets?
1) I.e. Customers that bought only product A but did not by product B
2) I.e. Customers that bought both product A and B
Thank you for your assistance.
D
You can try using the LEFT OUTER JOIN to get the result.