Are you referring to the form used for reports?

I don’t know why, but my ER-diagrams never has rings

Who can help me guys plz

are you referring to the form used for reports?

even insulting

No, it is quite OK to have loops in ER-dagramms

I didn’t quite understand what you were referring to, however I used this form, only to represent relationships, nothing more.

Yes I heard it. That’s why it is a bit insulting for me

provide more info on how you connect and where.
Now we can’t help

a ok now I understand , yes this form is used for cycles ok ahahhahah, but the site I used to create the er diagram gave me this form to represent the relationships

So do you advise me to delete the foreign key or leave it? Because the derivation rules of the relational model foresee the following form

FKs must be left like they are now. Don’t delete them

Loops in ER-diagrams are completely OK

Ok thanks for your help👍

You fks must be from sending user and receiving user field.
Those field will stay, so will the fks.

HI!
Table:
ORDERS (ID, PRODUCT_NAME, PRODUCT_PRICE, DATE_ORDER DATE, ID_CUSTOMER, AMOUNT);
How to calculate the average sum of the orders for the product ‘product-1’?

Where is your relation to product?

I eat to do like this:
SELECT AVG(AMOUNT) from ORDERS WHERE PRODUCT_NAME=‘product1’
but it doesn’t work

SELECT AVG(AMOUNT) from ORDERS GROUP BY PRODUCT_NAME

thanks!

and add WHERE PRODUCT_NAME=‘product1’?

As you wish

#ask why C.price Unkown colomn

Don’t repeat aliases names

OK so the naming of aliases cannot be the same

so I just need to change the alias name in C. price in inner join is correct

You need to use different names for each alias in query. What is unclear?

This is quite ok here as it is done in a subquery.

#ask good afternoon, how to display all data with conditions in a group based on its type and there is an additional 1 column in front of SQL. How do you do it?

Show DDL and explain what exactly do you want to get. Try to avoid abstract descriptions.

Oke im sorry my bad in english

Hi guys,
I have a blogs table and another table for multiple blog images.
I’m trying to get results for one blog and its multiple photos.
But I’m getting multiple result during query and json encode.
Any idea to save me?

Show DDL and explain what exactly do you want to get. Try to avoid abstract descriptions.

Hello guys!
I need your advise
There is a tool (web-portal) and this tool is used by 3 distributed teams in different locations (continents)
And the management wants to have own stage in each locations for availability purposes
And the question is how to replicate the data between 3 stages

Currently the database system is PostgreSQL

Unfortunately Postgres doesn’t have built-in master-master replication mechanism