I have 2 tables in a MySQL database: Products and ProductsType.
Each element of the Products table has a type which is contained in ProductsType table.
Each table has a field named "code".
I'd like to have a VIEW with the cartesian product of these 2 tables and I know that I can do it with a CROSS JOIN.
But I'd like that in this VIEW I can see the CONCAT of the 2 fields named "code" of my 2 tables. Is that possible?
I've also thought that I can make 3 tables, Products, ProductsType and ProductsWithType and in the first 2 I put some triggers "after insert" that keep updated the third table ProductsWithType, but I'd like to know if it is possibile to do with a view.
Thanks in advance
Are you looking for this?
CREATE VIEW vw_products_types AS
SELECT CONCAT(p.code, t.code) combined_code, p.product_name, t.type_name
FROM Products p CROSS JOIN ProductsType t
Here is SQLFiddle demo
Related
I have 2 tables:
acco_info
acco_revenue_2016
Both tables have different columns except for 1, acco_id.
This column is what connects both tables.
I want to write a query that combines important data from both tables and links them to the acco_id.
So from the acco_info table I need the following columns:
acco_id, acco_name, region_name, country_name
From the acco_revenue_2016 table I need:
acco_id, sales, revenue_per_item, revenue
The output should look like this:
acco_id, acco_name, region_name, country_name, sales, revenue_per_item, revenue
What's the best way to write this query?
I am stuck on
SELECT acco_id FROM acco_info UNION SELECT acco_id FROM acco_revenue_2016
This joins the ID's together but I can't find a way to also show the other data.
You'll be looking for something like this;
SELECT
ai.acco_id
,ai.acco_name
,ai.region_name
,ai.country_name
,ar.sales
,ar.revenue_per_item
,ar.revenue
FROM acco_info ai
INNER JOIN acco_revenue_2016 ar
ON ai.acco_id = ar.acco_id
This is assuming that both tables contain the same acco_id. Notice the table aliases to see which field is coming from each table
Here is the situation,
I have an interface with a dropdown(All, Category, Category type, Product) and search button. There are three database tables for each section as CATEGORY, CATEGORYTYPE and PRODUCT
When user select the All option search, I am getting results from all three tables and display on a HTML table.
TO do pagination, I want to fetch results set by set from all the tables.
Here are the three queries I'm using:
SELECT CATNAME,CATDESC,CATSTATUS FROM CATEGORY WHERE CATNAME like %a%
SELECT CATTYPENAME,CATTYPEDESC,CATTYPESTATUS FROM CATEGORYTYPE WHERE CATTYPENAME like %a%
SELECT PRODUCTNAME,PRODUCTDESC,PRODUCTSTATUS FROM PRODUCT WHERE PRODUCTNAME like %a%
From all the tables I'm only fetching the same set of column I want to combine the three queries. I hope my question is understandable. This is not about joining the three tables.. I want the results from all three queries to act as a one set or records and paginate them.
Thanks in advance for any suggestions and please ask if the question is not clear.
The application is JAVA EE based. Struts used and DB is MySQL.
Using view u can do what you want.
in very first u have to change columns heading as same. like
SELECT NAME,DESCRIPTION,STATUS FROM CATEGORY WHERE NAME like %a%
SELECT NAME,DESCRIPTION,STATUS FROM CATEGORYTYPE WHERE NAME like %a%
SELECT NAME,DESCRIPTION,STATUS FROM PRODUCT WHERE NAME like %a%
then you can create view like this
CREATE VIEW V AS
SELECT *
FROM ((CATEGORY NATURAL FULL OUTER JOIN CATEGORYTYPE)
NATURAL FULL OUTER JOIN PRODUCT);
P.S. if you can not change columns heading,you can have to change view according to that tables' columns
I have a MySQL statement that I want to use that will display the data in two different tables, but not have any duplicated data.
SELECT Customer.firstName, Customer.lastName, Purchase.productName, Purchase.productPrice
FROM Purchase
INNER JOIN Customer
This is currently the MySQL I am using and it does work, but it loads duplicated data which I do not want. I have looked around but not seeing a simple solution. Sorry in advance if it is a simple solution, been working for awhile and brain isn't really working.
You have to bind those tables via related columns.
Let's assume primary column of table Customer is named ID and customer ID is being held in a column named customerID in table Purchase:
SELECT Customer.firstName, Customer.lastName, Purchase.productName, Purchase.productPrice
FROM Purchase
INNER JOIN Customer
ON Custormer.ID=Purchase.customerID
I am trying to create a table that shows treatment information about patients (though I just wondered if would be better as a query) at a fictional hospital. The idea is that one row of this could be used to print an information sheet for the attending nurse(s).
I would like to make the attending_doctor column contain the name that corresponds with the employee_id.
|Patient_ID|Employee_ID|Attending_Doctor|Condition|Treatment|future_surgery|
Would appreciate any help. Thank you!
Just use a join in your query rather than have the employee name in 2 tables (which would mean updating in more than one location if they change name etc). For the sake of an example, this also gets the patients name from a 3rd table named patients.
eg
SELECT table1.*, employees.name, patients.name
FROM table1
LEFT JOIN employees ON employees.id = table1.employeeId
LEFT JOIN patients ON patients.id = table1.patientsId
Don't use directly this table, but build a view that contains the data you need. Then you can get the data from the view like it was a table.
Basically what you need is to have data in three tables. One table for patients, one table for for employees and one for the reports. Table with reports should contain only the employee_ID. Then you can either build a direct query over these three tables or build a view that will hide the complicated query.
This has been driving me mad.
I have three tables:
items
ID
name
type
cats
ID
name
items_to_cats
FK_ITEM_ID
FK_CAT_ID
This is a simple many-to-many relationship. I have items and categories. Each item can be linked to one or more categories. This is done via a simple joining table where each row maintains a relationship between one item and one category using foreign key constraints.
You will notice that my "items" table has a field called "type". This is an indexed column that defines the type of content stored there. Example values here are "report", "interview", "opinion", etc.
Here's the question. I want to retrieve a list of categories that have at least one item of type "report".
Ideally I want to get the result in a single query using joins. Help!
select distinct cats.id, cats.name
from cats
join items_to_cats on items_to_cats.fk_cat_id=cats.id
join items on items.id=items_to_cats.fk_item_id
where items.type='report'
Just as a point of database design, if you have a small set of legal values for items.type, i.e. "report", "interview", "opinion", maybe a couple more, then you really should create a separate table for that with, say, an id and a name, then just put the type id in the items table. That way you don't get into trouble because somewhere it's mis-spelled "raport", or even more likely, someone puts "reports" instead of "report".
or how about this :
SELECT c.id, c.name
FROM cats c
WHERE c.id IN
(SELECT ic.fk_cat_id
FROM items_to_cats ic
JOIN items i on i.id=ic.fk_item_id
WHERE items.type='report'
)