composite-key Questions

10

I was working on an Access database which loved auto-numbered identifiers. Every table used them except one, which used a key made up of the first name, last name and birthdate of a person. Anyways...

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I have a table that looks like this: CREATE TABLE IF NOT EXISTS list ( id UUID PRIMARY KEY DEFAULT gen_random_uuid(), tok TEXT, sid TEXT NOT NULL, aid TEXT, hash TEXT, qtt SMALLINT, p ...
Langmuir asked 23/11, 2023 at 20:42

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I have a table: table votes ( id, user, email, address, primary key(id), ); How can I make the columns user, email, address unique - i.e., ensure that there isn't any pair of rows that has id...
Disoperation asked 11/3, 2009 at 19:12

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Scenario: I have a table which references two foreign keys, and for each unique combination of these foreign keys, has its own auto_increment column. I need to implement a Composite Key that will ...
Grandeur asked 8/8, 2013 at 7:17

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I am reading about candidate keys and composite keys. I came to know that a candidate key can qualify as a primary key and it can be a single column or combination of columns and a composite key ...
Retina asked 10/4, 2011 at 6:51

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I am using Entity framework 4.1 in MVC 3 application. I have an entity where I have primary key consists of two columns ( composite key). And this is being used in another entity as foreign key. Ho...

6

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This is from Hibernate official tutorial: There is an alternative <composite-id> declaration that allows access to legacy data with composite keys. Its use is strongly discouraged for anyt...
Doubletongue asked 1/1, 2013 at 18:1

2

I have a database that contains a couple of composite foreign keys. For example, here is the generation script for the foreign key: ALTER TABLE [dbo].[WorkingRosters] WITH NOCHECK ADD CONSTRAINT [...

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I need to map based on two keys(comp and part). @foreach (var item in Model) { <tr> <td> @Html.DisplayFor(modelItem => item.comp) </td> <td> @Html.DisplayFor(model...
Knut asked 21/8, 2015 at 10:25

2

How to make a composite primary key on phpmyadmin. such that student id is combination of year and roll number. sid = 112132 , 11 of year 2011 and 2132 is roll number?? anybody help..
Gauhati asked 17/3, 2014 at 7:24

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I'm using Hibernate with annotations (in spring), and I have an object which has an ordered, many-to-one relationship which a child object which has a composite primary key, one component of which ...
Gree asked 9/4, 2010 at 23:36

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I have two tables table1 and table2 each having a column named email along with different other columns. What I want is a validator which looks for uniqueness in email field of both the columns. I ...
Phebephedra asked 18/6, 2012 at 17:14

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Is there a syntax for passing composite keys, i.e. lists and objects, like the below example, or is that by-design? > obj = {[1, 2]: 3}; SyntaxError: Unexpected token [ The second example wor...
Corelative asked 16/6, 2011 at 18:18

4

I am trying to use Spring Data Cassandra using Composite primary key class. But when I try to query data I get an exception: org.springframework.data.repository.query.QueryCreationException: **Cou...

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I'm trying to create a relation where any of four different parts may be included, but any collection of the same parts should be handled as unique. Example: An assignment must have an assigned co...
Biel asked 9/1, 2009 at 21:26

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In Datomic, how do you efficiently perform queries such as 'find all people living in Washington older than 50' (city and age may vary)? In relational databases and most of NoSQL databases you use ...
Yellowgreen asked 3/7, 2014 at 19:0

0

I'm using JPA to define a datamodel for a database with composite keys. I cannot change the database. I have got a Car entity with a composite key (carType and carId). A second (optional) Porsche...
Jealous asked 24/1, 2019 at 13:20

2

I am building an OData Web Service using WebAPI and OData v4. I was able to get the service to support composite keys through overriding the SelectAction method of the EntityRoutingConvention. How...
Premer asked 18/12, 2014 at 0:13

8

In this code, how to generate a Java class for the composite key (how to composite key in hibernate): create table Time ( levelStation int(15) not null, src varchar(100) not null, dst varchar(1...
Tiresome asked 27/8, 2010 at 14:17

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I have a table that has two foreign keys to two different tables with both foreign keys sharing one column: CREATE TABLE ZipAreas ( country_code CHAR(2) NOT NULL, zip_code VARCHAR(10) NOT NULL, ...
Rush asked 20/11, 2010 at 6:1

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Here is a gross oversimplification of an intense setup I am working with. table_1 and table_2 both have auto-increment surrogate primary keys as the ID. info is a table that contains information ab...

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Say I want to design a system where users can create posts, where each post belongs to one user but a user may have multiple posts. Also assume I want to support finding all posts given a userID in...
Mallorie asked 10/7, 2017 at 20:26

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I have 2 tables as follows : TABLE_A ------- A_SIREN A_NDA TABLE_B ------- B_id B_NDA B_SIREN The id of table A is a COMPOSITE KEY SIREN/NDA Here's the entities code. Key class @Embeddable ...
Hypogeal asked 28/4, 2017 at 14:7

1

I have a database that has a table with a 2-column primary composite key (one int, one bigint.) I have two tables that have a composite foreign key, referencing the first table's composite primary ...

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I am sure I am not the first who has composite unique keys in tables and who wants to validate them. I do not want to invent the bicycle so I ask here first. I have several tables that have 'id' co...
Displode asked 10/8, 2010 at 1:51

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