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Questions tagged [relation]

A relation on sets S1, S2, ..., SN is any subset of S1 x S2 x ... x SN, where 'x' denotes the Cartesian product. In other words, a relation over N sets is any set of ordered N-tuples over the N sets.

A relation on sets S1, S2, ..., SN is any subset of S1 x S2 x ... x SN, where 'x' denotes the Cartesian product. In other words, a relation over N sets is any set of ordered N-tuples over the N sets.

1457 questions
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Column not found: 1054 Unknown column 'product_name' in 'field list'")

when I want to attach the categories() to productTableSeeder : SQLSTATE[42S22]: Column not found: 1054 Unknown column 'product_name' in 'field list' (SQL: insert into category_product (category_id, product_name) values (1,…
hamidprog2003
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Make Relation for every tables

Here are my tasks, I'm quite new to the field (Mysql/Postgresql) if there possible explain me easy much as possible Create 4 tables 1. Chats 2. Messages 3. Files 4. Users Create 3 users. 2 common users, 1 admin. Users can create chat and write…
Edgar Cherqezyan
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Inquiry about about OUTER JOINS in SQL

In sql, if we have the following relations : A(B,C) with values { (1,2), (3,4), (5,6) } D(B,E) with values { (1,2), (3,4), (7,8), (9,10) } Would the resulting table be BCE with values { (1,2,2), (3,4,4), (5,6,null), (7,null,8), (9,null,10) } for…
Ahmed Akbarali
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Mysql select no relation from two tables

I have two tables first one has PRODUCTS_ID and second table has the relation between products for example product 1 has relation with product (2,3,4,5) as shown in PRODUCT_CONN. What I need to get the products listed on Table 1 that has no relation…
Mina
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Laravel relation total count

I have a Category model and a Description model. When displaying my categories in a list, I also want to include a total number of related descriptions for all categories, but without having to load all the descriptions itself. Using withCount works…
Hardist
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Math - Relation of 2 algorithm

Two expression with A and B: A = 2^(3(log_3 n)) B = 6(n^2) As i need to indicate whether A is big-Oh, big-Omega, or big-theta of B, is that A=O(B)? how to solve this?
ttllm
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MySQL database relationship without an ID

Hi StackOverflow community, I have these two tables: tbl_users ID_user (PRIMARY KEY) Username (UNIQUE) Password ... tbl_posts ID_post (PRIMARY KEY) Owner (UNIQUE) Description ... Why always everybody make database relationships with foreign…
Nicolas Harrinston
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OneToMany between 2 classes with Hibernate

I'm trying to get the hang of Hibernate. After getting my project to compile, I've started to convert my classes to be "Hibernate-enabled" Currently, I'm having 2 classes 1) Person (id, name, firstname, ...) 2) Task (Id, name, description,…
Matt
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Self Nested SQL join

I need this result this table. This is 3 column and I want 3 results with nested node. Really I want each node with self and parent like result ID/ Number/SelfRef 21092 100 NULL 21093 50 NULL 21094 30 21093 21095 20 21093 21096 -30…
Amin Sabaghi
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meta_query , why does not it work relation = or?

'width_picture', 'value' => array( $_GET['width_min'], $_GET['width_max'] ), 'compare' => 'BETWEEN'); $param_2 = array( 'key' => 'height_picture', 'value' => array( $_GET['height_min'], $_GET['height_max'] ),…
Serhiy
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(sql) input using select statement

i wanna make a project to find a rented house / room user can post his room/house to rent and others can see it on the map first user should login then he register his location in table location. table location consist id_location, lat, lng,…
progamernotprogrammer
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Can you give me an example of a transitive closure of a relation that is not an equivalence relation?

I am having trouble finding examples of transitive closure of relations that are not an equivalence relation.
Ahsen Waqar
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SQL parent child table query

I have two tables: parent and child. Parent table has columns Pid, Pname and Pgroup Child table has columns Cid, Pid I need an sql query to count number of child rows with Pgroup = 1.
Himanshu Tiwari
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Does laravel can create relationship between tables in sql database server?

I have a laravel project working fine but i can't see relationship in sql server.(for which i am using xampp). I expect the foreign-id in laravel is the foreign id in actual table. It is working fine in laravel, i expect it to work in actual…
Ganesh Adhikari
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php, 3 array to one array merge alternative

I have 3 arrays. These inter-related. I want to combine these statements. 1, 'title' => 'Title 1', 'content' => 'Content 1' ), array ( 'id' => 2, …
Scaffold
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