I am trying to append data from two tables in my dataBase to a third table with this code in a Microsoft Access database:
INSERT INTO percentage ( productId, productName, salesPrice, currentProvider, offerProvider, offerPrice, percentage )
SELECT products.productId AS productId, products.productName AS productName, products.pricePerUnitOrKg AS salesPrice, products.providerId AS currentProvider, productsByProviders.providerId AS offerProvider, productsByProviders.pricePerUnitOrKg AS offerPrice, Round(products.pricePerUnitOrKg/productsByProviders.pricePerUnitOrKg,3) AS percentage
FROM products INNER JOIN productsByProviders ON products.productId = productsByProviders.productId
Since the primary key in percentage is a composite key combined of the two fields: productId and offer provider, I want to make sure the row, (offer) - doesn't already exist in the percentage table with this code:
WHERE NOT Exists (SELECT 1 FROM percentage WHERE percentage.productId = productsByProvider.productId AND percentage.offerProvider = productsByProvider.providerId));
which I saw used here: How to use NOT EXISTS with COMPOSITE KEYS in SQL for inserting data from POJO
This isn't working, and I keep getting an error when trying to append to the table, which says:
And when I click yes, it doesn't append the rows that don't exist in the percentage table, which is what I want it to do.
Why is this happening?
I removed the NOT EXISTS part of the query, like June7 suggested in the comments, and it works, the error is still showing up, but for my purposes, this is enough.
Related
I am building an application to manage an inventory and I have a problem when creating my tables for the database (I am using PostgreSQL). My problem is the following:
I have two tables, one called 'products' and one called 'users'. Each one with its columns (See image). I want to create a third table called 'product_act_register' , which will keep a record of activity of the products and has with it the columns id, activity_type, quantity, date. But, I want to add other columns which are taken from the table 'users' and 'products'.
It should look like this (Image)
Where product_id, product_name, product_category, product_unit are taken from the table 'products' and the column 'user_id' is taken from the table 'users'.
How can I do this with PostgreSQL ?
Your description and your precise goals are very unclear. You didn't tell us what should happen in the different cases (only a product exists or only a user exists or none exist or both exist). You also didn't tell us how the other columns not coming from these tables should be filled. You furthermore didn't tell us how the tables users and products depend on each other. Basically you con do something like this if you only want to do an insert if both tables have an entry:
INSERT INTO product_acts_register
SELECT 1,'ActivityType1',p.id, p.name, p.category,
p.unit, u.id, 100, CURRENT_DATE
FROM products p JOIN users u ON p.id = u.id;
(Since you didn't tell us how or if to join them, I assumed to join on their id column)
If you don't care about this, but want to insert an entry for any possible combination of users and products, you can just select both tables without joining:
INSERT INTO product_acts_register
SELECT 1,'ActivityType1',p.id, p.name, p.category,
p.unit, u.id, 100, CURRENT_DATE
FROM products p, users u;
You can replicate this here and try out other commands: db<>fiddle
Please be more precise and give us more information when asking the next question.
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
I have two tables, one for Customer and one for Item.
In Customer, I have a column called "preference", which stores a list of hard criteria expressed as a WHERE clause in SQL e.g. "item.price<20 and item.category='household'".
I'd like a query that works like this:
SELECT * FROM item WHERE interpret('SELECT preference FROM customer WHERE id = 1')
Which gets translated to this:
SELECT * FROM item WHERE item.price < 20 and item.category = 'household'
Example data model:
CREATE TABLE customer (
cust_id INT
preference VARCHAR
);
CREATE TABLE item (
item_id INT
price DECIMAL(19,4)
category VARCHAR
);
# Additional columns omitted for brevity
I've looked up casting and dynamic SQL but I haven't been able to figure out how I should do this.
I'm using PostgreSQL 9.5.1
I'm going to assume that preference is the same as my made up item_id column. You may need to tweak it to fit your case. For future questions like this it may pay to give us the table structures you are working with, it really helps us out!
What you are asking for is a subquery:
select *
from item
where item_id in (select
preference
from
customer
where id = 1)
What I would suggest though is a join:
select item.*
from item
join customer on item.item_id = customer.preference
where item.price<20 and
item.category='household'
customer.id = 1
I decided to change my schema instead, as it was getting pretty messy to store the criteria in preferences in that manner.
I restricted the kinds of preferences that could be specified, then stored them as columns in Customer.
After that, all the queries I wanted could be expressed as joins.
I've created two temp tables. One with Orders which contains Article and Quantity and the other one with availability where we also have Article and Quantity. I would like to write a multi update query with subtracking order quantity from stock and from itself for all articles in temporary table with Orders. As far as I know it is not possible to alter two fields from different tables in one update query.
I've tried something like this, but it's of course doesn't work.
UPDATE #Stocks as s
INNER JOIN #Orders as o on o.ArticleId=s.ArticleId
SET
s.Quantity = (s.Quantity - o.Quanity)
FROM
#Stocks s
JOIN #Orders o on o.ArticleId=s.ArticleId
WHERE
#Stocks.ArticleId IN (SELECT ArticleId FROM #Orders)
When do you an update using a join with multiple matches, only one arbitrary row is chosen for the update. The key idea is to aggregate the data before the update:
UPDATE s
SET Quantity = (s.Quantity - o.Quanity)
FROM #Stocks s JOIN
(SELECT o.ArticleId, SUM(o.Quantity) as quantity
FROM #Orders o
GROUP BY o.ArticleId
) o
ON o.ArticleId = s.ArticleId;
Your statement is way over-complicated, mixing update syntax from SQL Server, MySQL, and Postgres. In addition, the WHERE clause is unnecessary because the JOIN does the filtering. However, even once the syntax errors are fixed, you will still have the problem of calculating incorrect results, unless you pre-aggregate the data.
Unfortunately, the description of this behavior is buried deep in the documentation of the first example on the update page:
The previous example assumes that only one sale is recorded for a
specified salesperson on a specific date and that updates are current.
If more than one sale for a specified salesperson can be recorded on
the same day, the example shown does not work correctly. The example
runs without error, but each SalesYTD value is updated with only one
sale, regardless of how many sales actually occurred on that day. This
is because a single UPDATE statement never updates the same row two
times. [emphasis added]
How about this?
UPDATE s
SET s.Quantity = (s.Quantity - o.Quanity)
FROM #Stocks as s
INNER JOIN #Orders as o on o.ArticleId=s.ArticleId
For updating two tables using single query, you should create a view that contain both tables columns and then update that view.
Your Question is all about Multi Update,
but updation perform in one table based on another table so
to do this use join
But if updation perform in two or more table we have to create view then we can update
thanks
I am having trouble with writing a SQL query in Access with foreign keys. There are two tables, 'Customers'(ID, Name, Surname) and 'Orders'(ID, Customer, Date, Volume). ID fields are primary, and Orders.Customer is a foreign key linked to Customers.ID, so a customer can have many orders or none.
My goal is to do a search on customers based on many criteria, one of which being if customers have at least an order which volume is superior to a certain quantity. I tried joins with SELECT DISTINCT but it still gives me duplicate results, plus I had to create an empty order for every customer without orders if the query didn't use the above condition.
Does anyone have an idea about that? Maybe some special instruction on foreign keys or 2 separate queries?
Based on the information you give, i only can give you hints on what I think you're doing/understanding wrong :
SELECT DISTINCT does select you a unique record, not a unique value, so if your statement selects all fields (*), distinct won't help you much there.
My guess is you had to create an empty order for each customer because you used INNER JOIN, try LEFT OUTER JOIN instead
For example :
SELECT DISTINCT Customers.*
FROM Customers
LEFT OUTER JOIN Orders
ON (Orders.Customer = Customers.id)
WHERE Volume > put_your_value