I have following tables: Product and ProductEvent. Some of the relevant columns of Product table are SocialID, MarketID, LocalID. These three columns have numbers that corresponds to one column called EventID in ProductEvent.
Here is my question: is there a better way to join these tables where I do not have to make 3 separate joins all pointing to match EventID?
Maybe something like this:
select *
from Product P join ProductEvent PE
on (PE.EventID = P.SocialID or PE.EventID = P.MarketID or PE.EventID = P.LocalID)
Related
I'm trying to search one table for entities with a certain field in one table and use fields within that entity to to join it with two other tables specific fields
first I search for entities with CustomerID == 2 and use their other fields to search to other tables
Using BoxTypeID from those specific entities I want to find the corresponding BoxType
Using WarehouseID from those specific entities I want to find the corresponding name
Once I have found all three fields (BoxID, BoxType, name) I want to display them all in one table
I have some SQL that works but only displays the BoxID and Warehouses.name. I can get it to also display BoxID and BoxType however not all three at once.
SELECT Boxes.BoxID, Warehouses.name AS Warehouse
FROM Boxes
INNER JOIN Warehouses
ON Boxes.WarehouseID = Warehouses.WarehouseID
WHERE Boxes.CustomerID = 2;
resulting table from query above
However once I try to apply another JOIN it doesn't work
SELECT Boxes.BoxID, Warehouses.name AS Warehouse, BoxTypes.BoxType as Size
FROM Boxes
INNER JOIN Warehouses
ON Boxes.WarehouseID = Warehouses.WarehouseID
INNER JOIN BoxTypes
On Boxes.BoxTypeID = BoxTypes.BoxTypeID
Where Boxes.CustomerID = 2;
Hi guys I'm new with databases and I'm trying to make a query where I join 3 tables. I could make it and I want to clean up the result. I want to know how can I delete the column "pin" from users table and maybe some "ids" columns.
Select * from "wish-list"
Join products
On "wish-list".id = products.holiday_id
Join users
On "wish-list".user_id = users.id
Where "wish-list".id = 1
You need to specify which columns you really need in your output. At the moment you are using
SELECT * which outputs all columns of all joined tables.
Here is what it should look like:
SELECT holiday, products.description, users.pin FROM "wish-list"
JOIN products ON "wish-list".id = products.holiday_id
JOIN users ON "wish-list".user_id = users.id
WHERE "wish-list".id = 1
It's important that you reference all columns which are not your main entity (here wish-list) with tablename.column (products.description and not only description). It will work without referencing strictly but only if the column name is unique in your query.
Furthermore you can rename columns. This is useful for example if you want to get the id's of the product table and the wish-list table.
SELECT product.id AS product_id, id AS wishlist_id FROM "wish-list"
...
Hope that helps!
I have a table called Target where I have 5 columns:
ProductLevel
ProductName
CustomerLevel
CustomerName
Target
In another table called Products I have 3 columns:
ProductId
ProductCategory
ProductBrand
In the 3rd table called Customer I have 3 columns:
CustomerID
CustomerName
SubCustomerName
Is there a way to do a dynamic join where I select the column I will use in the JOIN based on the value that I have in the 1st table?
Example: If in the first table I have Category in ProductLevel, I'll join the table product using ProductCategory field. If I have Brand, I'll join using ProductBrand... The same happens with Customer table.
PS: I'm looking for a way to create it dynamically in a way I can add new columns to that tables without changing my code, then in the future I can have ProductSegment column in Product Table and Segment as a value in ProductLevel in Target table.
Yes, like this:
SELECT * FROM
Target t
INNER JOIN
Product p
ON
(t.ProductLevel = 'Category' AND t.??? = p.ProductCategory)
OR
(t.ProductLevel = 'Brand' AND t.??? = p.ProductBrand)
You didn't say which column in Target holds your product category/brand hence the ??? in the query above. Replace ??? with something sensible
PS; you can't do as you ask in your PS, and even this structure above is an indicator that your data model is broken. You can at least put the code in for it now even if there are no rows with t.ProductLevel = 'Segment'
Don't expect this to perform well or scale.. You might be able to improve performance by doing it as a set of UNION queries rather than OR, but you may run into issues where indexes aren't used, crippling performance
Here is a basic illustration of the issue
I have two tables I want to join.
One table contains information about a product sale. (product_sales)
The other contains keys for the names of locations. (states_keys)
Both contain the same column 'state_key'.
The states_keys table has an additional column called 'state_names'.
I would like to join the table so that I can view the accurate state name that coordinates to each product sale.
So, I want to join where each table's state_key are = but display the additional column state_names from table states_keys.
SELECT product_sales.*, state_names
FROM product_sales
INNER JOIN states_keys
ON product_sales.state_key = states_keys.state_key
Try with something like this:
Select prod.*, state.state_names
from product_sales prod
inner join states_keys state on state.state_key = prod.state_key
i hava a set of following tables
customer(cus_id,cus_name);
jointAccount(cus_id,acc_number,relationship);
account(acc_number,cus_id)
now i want to create a select statement to list all the jointAccounts,
it should included the both customer name, and relationship.
I have no idea how to retrieve both different user name, is that possible to do this?
Generally speaking, yes. I'm assuming you mean you want to get customer info for both sides of the joint account per your jointAccount table. Not sure what database you're using so this answer is assuming MySQL.
You can join on the same table twice in a single SQL query. I'm assuming you have not yet created your tables, as you have cus_id listed twice in the jointAccount table. Typically these would be something like cus_id1 and cus_id2, which I've used in my sample query below.
Example:
SELECT c1.cus_id AS cust1_id, c1.cus_name AS cust1_name
, c2.cus_id AS cust2_id, c2.cus_name AS cust2_name, j.relationship
FROM customer c1
INNER JOIN jointAccount j
ON c1.cus_id = j.cus_id1
, customer c2
INNER JOIN jointAccount j
ON c2.cus_id = j.cus_id2
I haven't tested this but that's the general idea.
try this query:
SELECT * FROM jointAccount a LEFT JOIN customer c ON a.cus_id = c.cus_id;
just replace the * with the name of the columns you need.