I believe I have formed this question title correctly because I wasn't sure how to form it. As an example, I have summarized my query below.
I have an order table which saves order details like customer id, address and product ids and quantity ordered for each order in a row. So multiple inventory/product ids are saved in a single row.
so my query looks like: this is a summarized query for an easier explanation I have omitted various other fields.
SELECT customer.name,customer.address,tbl_order.order_date,tbl_order.product1_id,tbl_order.product2_id,inventory.product1_name,inventory.product2_name
FROM tbl_order
INNER JOIN customer ON tbl_order.customer_id = customer.id
INNER JOIN inventory on tbl_order.product1_id = inventory.id
INNER JOIN inventory on tbl_order.product2_id = inventory.id
where YEAR(tbl_order.order_date)='$year'
So my question is how to get the inventory details from the inventory table based on each product id from tbl_order. I am running a while loop to show all data for a year
while($row=mysqli_fetch_assoc($sql1))
I can divide this query into 2 and run the inventory query individually but then how to combine the while loop, as sometimes there could also be empty query when some products are not in order table (depending on order to order, not all products are ordered) so this doesn't work
while($row=mysqli_fetch_assoc($sql1)) and ($row1=mysqli_fetch_assoc($inv1)) and ($row2=mysqli_fetch_assoc($inv2))
and so one for 10 products
First, of all you have bad DB design and I kindly advice to normalize your DB.
Second, if you can not re-design the DB you can use multiple joins with aliases like:
SELECT
customer.name, customer.address, tbl_order.order_date,
tbl_order.product1_id, inv1.product1_name,
tbl_order.product2_id, inv2.product2_name
FROM tbl_order
INNER JOIN customer ON tbl_order.customer_id = customer.id
INNER JOIN inventory AS inv1 ON tbl_order.product1_id = inv1.id
INNER JOIN inventory AS inv2 ON tbl_order.product2_id = inv2.id
WHERE YEAR(tbl_order.order_date)='$year'
Related
My database has 3 tables. One is called Customer, one is called Orders, and one is called RMA. The RMA table has the info regarding returns. I'll include a screen shot of all 3 so you can see the appropriate attributes. This is the code of the query I'm working on:
SELECT State, SKU, count(*)
from Orders INNER JOIN Customer ON Orders.Customer_ID = Customer.CustomerID
INNER JOIN RMA ON Orders.Order_ID = RMA.Reason
Group by SKU
Order by SKU
LIMIT 10;
I'm trying to get how much of each product(SKU) is returned in each state(State). Any help would really be appreciated. I'm not sure why, but anytime I include a JOIN statement, my query takes anywhere from 5 minutes to 20 minutes to process.
[ Customer table]
!2[ RMA table]
!3
Your query should look like this:
SELECT c.State, o.SKU, COUNT(*)
FROM Orders o INNER JOIN
Customer c
ON o.Customer_ID = c.CustomerID JOIN
RMA
ON o.Order_ID = RMA.Order_Id
GROUP BY c.State, o.SKU
ORDER BY SKU;
Your issue is probably the incorrect JOIN condition between Orders and RMA.
If you have primary keys properly declared on the tables, then this query should have good-enough performance.
Given you are joining with an Orders table I'm going to assume this table contains all the orders that the company has ever done. This can be quite large and would likely cause the slowness you are seeing.
You can likely improve this query if you place some constraint on the Orders you are selecting, restricting what date range you use is common way to do this. If you provide more information about what the query is for and how large the dataset is everyone will be able to provide better guidance as to what filters would work best.
i have a problem in MySQL where I use the COUNT function for conditions. However, when combining this with joins, although I use grouping, the COUNT values include ALL rows, even the ones filtered out.
I'm providing a minimal working example, which however maybe does not make a practical sense or is designed smartly.
So assume I have 3 tables:
products with fields: productId, name, active (boolean)
teams with fields: teamId, name
rel_production with fields: teamId, productId
So basically I have products and teams with ids and names. Products can be active (lets say that means that they are still in production or so).
And then I have a relation which team is working on which product.
To explain my problem, assume the following minimal amount of data to clarify the problem is contained inside the tables:
products
teams
rel_production
Now the query that I want to do is, in plain english: "I want all teams that are working on exactly 2 products while atleast one product must be active."
The query in general works and is the following in mysql:
SELECT
teams.*,
"r_count:",
r_count.*,
COUNT(r_count.productId),
"r_active:",
r_active.*,
"p_active:",
p_active.*
FROM teams
INNER JOIN rel_production r_active ON r_active.teamId = teams.teamId
INNER JOIN products p_active ON p_active.productId = r_active.productId AND p_active.active
INNER JOIN rel_production r_count ON r_count.teamId = teams.teamId
GROUP BY teams.teamId, r_active.teamId
HAVING COUNT(r_count.productId) = 2 #4 is the problem!!!!!!!!!!!!!
Now them problem is with team 1. Because it is working on 2 active products, COUNT(r_count.productId) will be 4 and not 2. So my query will filter it out.
Here is the screenshot with the result without the HAVING clause:
I see why this happens, because the two inner joins on rel_production will cause 4 rows to be generated. But then they are merged always together to one using the GROUP BY. So what I need is the COUNT after the GROUP and not before.
How can I fix this?
Perform the filtering on teams in a separate subquery, and then join to that:
SELECT
t1.teamId,
t1.name
FROM teams t1
INNER JOIN
(
SELECT t1.teamId
FROM rel_production t1
INNER JOIN products t2
ON t1.productId = t2.productId
GROUP BY t1.teamId
HAVING COUNT(DISTINCT t1.productId) = 2 AND SUM(t2.active) > 0
) t2
ON t1.teamId = t2.teamId;
SQLFiddle
I currently have 4 SQL tables that look like this:
CustomersTable, RegistrationTable, OrdersTable and OffersTable
enter image description here
I need to write a SELECT statement that retrieves all customers from the CustomersTable (all the fields) that contain rows that match the RegistrationTable Or rows that match the OrdersTable with status "closed", in the result table shouldn't display duplicate customers.
As you realized, CustomersTable and RegistrationTable have the field in common "customerId", but between CustomersTable and OrdersTable there is no field in common. However there is another table (OffersTable) which has the fields "customerId" and "ID", to query information to Customers and Orders table respectively. Remember that a customer who appears in OfferTable not necessarily will appear in OrderTable or just the status is NOT "Closed"
So based on my example tables above, if I were to run the query, it would return the following result:
enter image description here
In the result table shouldn't display duplicate customers.
I really appreciate your help.
Thanks for your time !!
Note - I am using MySQL
Try Using "Union" and "inner join" with every table Like below:
Select Customers.* from Customers inner join Registration on Customers. customerId= Registration.customerId
union
Select Customers.* from Customers inner join offers on Customers.customerId=offers.customerId
inner join Orders on orders.Id= offers.Id and Orders.Status='closed'
I would think exists or in, given what you want. Your description of the table is a bit cumbersome -- which is why sample data in the question is so helpful.
The resulting query would look something like this:
select c.*
from customers c
where exists (select 1 from registrations r where r.customerid = c.customerid) or
exists (select 1
from offers o join
orders oo
on o.id = oo.orderid
where o.customerid = c.customerid and
oo.status = 'closed'
);
The column names may not be quite right.
I am trying to learn joins with many to many relationships in mysql,
I have four tables:
customers, orders, products, payments
I am trying to get records as:
customer_name, order_status, pay_method, pro_name
the query I use:
SELECT cust_name,order_status,pay_method,pro_name FROM customer
INNER JOIN orders ON customer.cust_id = orders.cust_id
INNER JOIN payments ON payments.order_id = orders.order_id
INNER JOIN products ON products.pro_id = orders.pro_id
I am receiving results as I want with no issue. But this query shows only one product against one order, then I realize I should have another separate table which will hold many products against one order. In this issue I am not able to get desired result
It's not entirely clear what you're asking, but I'm guessing what you're trying to do is create a many to many table that links orders and products? In which case, you can just create a table called "productorders" which will contain an order_id and a pro_id. Then you would modify your query like this:
SELECT cust_name,order_status,pay_method,pro_name FROM customer
INNER JOIN orders ON customer.cust_id = orders.cust_id
INNER JOIN payments ON payments.order_id = orders.order_id
INNER JOIN productorders ON productorders.order_id = orders.order_id
INNER JOIN products ON products.pro_id = productorders.pro_id;
Joining productorders will get all products associated with an order, and then joining products will get the information associated with each product.
I posted a question about 2 weeks ago about 'one to many' relation between SQL tables. Now I have a bit of a different scenario. Basically, there are two tables - coffee_users and coffee_product_registrations. The latter is connected to coffee_users table with 'uid' column. So basically coffee_users.uid = coffee_product_registrations.uid
A single user can have multiple products registered.
What I want to do is to display some product information (from coffee_product_registrations) along with some user information (from coffee_users), BUT retrieve only those rows that have more than 1 product registrations.
So to simplify, here are the steps I need to take:
Join two tables
Select users that have multiple products registered
Display all their products along with their names and stuff
My current SQL query looks like this:
SELECT c.uid, c.name, cpr.model
FROM coffee_users c
JOIN coffee_product_registrations cpr on c.uid = cpr.uid
GROUP BY c.uid
HAVING COUNT(cpr.uid) > 1
This joins the two tables on 'uid' column but displays only 1 row for each user. It selects just users that have multiple products registered.
Now I need to take these IDs and select ALL the products from coffee_product_registrations based on them.
I cannot figure out how to put this in one query.
Replace cpr.*, c.* with columns which you want to extract feom the query
Try this:
SELECT cpr.*, c.*
FROM coffee_product_registrations cpr
INNER JOIN coffee_users c ON c.uid = cpr.uid
INNER JOIN (SELECT cpr.uid
FROM coffee_product_registrations cpr
GROUP BY cpr.uid
HAVING COUNT(DISTINCT cpr.productId) > 1
) AS A ON c.uid = A.uid;