I would like to merge 2 tables, giving the example below would be the best illustrations. Thank you
Tables
Related
I’m curious about ctes in postgres db , I tried to use join inside but i got an error!
My questions ?
Could i use where of multiple tables instead of inner join with a cte ?
Is there another way to save table results if not cte suitable? I revised variables and they only suitable for one row ?
I used views, it is a better alternative. if somebody curious.
I have two tables, by joining that 2 tables i need to take distinct count of one particular column from OrientDB. Since joins donot support in OrientDB. Please suggest me in orient db how join works and please suggest me also how to use edges for join in orientdb.
Hi, I have trouble understanding the structure of this table connection.
Let's suppose that all joins are inner join. Does this picture mean:
Orders JOIN (Orders1 JOIN People) JOIN Returns?
or
Orders JOIN Orders1 JOIN (People JOIN Returns)?
I don't understand
Why Orders1 and People are both vertically aligned and both connected with Orders table.
(As my understanding, join operation is bilateral, not trilateral. My imagination is that the joining should be all represented horizontally, looking like a chain.)
I know SQL, it would be easier to explain if write a pseudo SQL script.
The example you have taken is not very good to understand the joins/relationships in tableau.
A wire/line between two tables indicate the join on two tables with some id column (one to many OR one to one OR many to many). You can check the relationship based on which field (read column) by clicking that relationship thread(line). Why I termed this example not a good one because ORDERS table joining itself may have umpteen options. You can edit that relationship in many ways.
So, in you example, ORDERS is joined with itself (ORDERS1). (the result will depend on relationship type of course). Simultaneously ORDERS is joined with PEOPLE table. Since these tables have only one field in common, this relationship has resulted in creation of just one extra column in ORDERS result. NoW PEOPLE is also connected with RETURNS where no column is common so I am not able to understand this relationship.
A watch of this 5 minute video is recommended.
Translating this relationship will be something like..
(ORDERS JOIN (PEOPLE JOIN RETURNS)) JOIN ORDERS1
(Last JOIN outside braces is on the result of braces but with field/fields from ORDERS)
Anyone know what is the ORM function for joining multiple db tables in ERPNext?
I need query result from 2 DB tables join using script report
*I don't need query report answer since i already have it. I only looking for an example do it using script report
Frappe currently doesn't have ORM support for joining tables. You might have to use frappe.db.sql for the time being.
data = frappe.db.sql(
"""
select tb1.name from tabTable1 as tb1
left join tabTable2 as tb2 on tb1.name = tb2.employee_name;
"""
);
return data
Okay. So the question that I got asked by the teacher was this:
(5 marks) Construct a SQL query on the dvdrental database that uses a natural join of two or more tables and an additional where condition. (E.g. find the titles of films rented by a particular customer.) Note the hints on the course news page if your query returns nothing.
Here is the layout of the database im working with:
http://www.postgresqltutorial.com/wp-content/uploads/2013/05/PostgreSQL-Sample-Database.png
The hint to us was this:
PostgreSQL hint:
If a natural join doesn't produce any results in the dvdrental DB, it is because many tables have the last update: timestamp field, and thus the natural join tries to join on that field as well as the intended field.
e.g.
select *
from film natural join inventory;
does not work because of this - it produces an empty table (no results).
Instead, use
select *
from film, inventory
where film.film_id = inventory.film_id;
This is what I did:
select *
from film, customer
where film.film_id = customer.customer_id;
The problem is I cannot get a particular customer.
I tried doing customer_id = 2; but it returns a error.
Really need help!
Well, it seems that you would like to join two tables that have no direct relation with each other, there's your issue:
where film.film_id = customer.customer_id
To find which films are rented by which customer you would have to join customer table with rental, then with inventory and finally with film.
The task description states
Construct a SQL query on the dvdrental database that uses a natural join of two or more tables and an additional where condition.quote