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According to the definition, a Junction Table (bridge table/link table) is used for many-to-many relationships, when used like this:
CREATE TABLE Users ( UserLogin varchar(50) PRIMARY KEY, UserPassword varchar(50) NOT NULL, UserName varchar(50) NOT NULL...
Started by pez_dispenser on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
The question....
We use these terms.
There is not any reason why a junction table couldn't be used for a one-to-many relationship of "Junction" table, "associative" table, "join" table -- it's just a table.
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I have 2 regular Tables "Tasks" and "Employees" and one junction table EmployeeTasks simplified they look like this
Tasks
TaskID ProjectID Duration Employee
EmployeeID EmployeeName EmployeeTasks
EmployeeID TaskID I am trying to find a tsql query that ...
Started by John on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
SELECT Count(TaskID) as NumOfTasks, Sum(Duration) as TimeSpent FROM Employee INNER JOIN EmployeeTasks on Employee.EmployeeID = Tasks.EmployeeID INNER JOIN Tasks on EmployeeTasks... .
Note this is different if you need to show time for an employee who has no tasks .
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I have two sql tables Players and Teams joined by a PlayerTeam junction table. A player can be on a team for various years. What's the best way to handle this relationship? I started with a PlayerTeamYear table, but the foreign key reference to both columns...
Started by Bob_Kruger on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Think....
I'd actually add two columns to the PlayerTeam table: a year and a surrogate key to act as your primary key.
The suggestion above is a good one.
I would add the year to the PlayerTeam table so it has three columns in its primary key.
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Hi everyone!
A "plain SQL question" :) I have two tables and a third one that acts as a "semi junction table", meaning that sometimes there's just one of the two foreign keys.. Is there a way to join them?
For example, given the following data:
Table ...
Started by Joril on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
SELECT d.*, c.* FROM d JOIN junction j ON j.d_id = d.id LEFT JOIN с ON c.id = j.c_id
You should.
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This is a follow up question to this one:
http://stackoverflow.com/questions/416565/query-examples-in-a-many-to-many-relationship
regarding updating the junction table. To do this, I would have to use both key values in the junction table, in the WHERE...
Started by Soeren on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
The temp table?
CREATE PROCEDURE dbo.test ( @UserId int, @AddressId int ) AS update UserAddresses set.
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I have 3 tables
1) tblPurchaser having 2 columns:
PurchaserId PurchaserName 1 A1 2 A2 3 A3
2) tblCar having 2 columns:
CarId Carname 11 C1 12 C2 13 C3 14 C4
And the last is a junction table tblInformation where the information about those persons are ...
Started by priyanka.sarkar on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
table(PurchaserId int, PurchaserName varchar(4)); insert @soPurchaser select 1,'A1' insert @soPurchaser select 2,'A2' insert @soPurchaser select 3,'A3' Declare @SOtblCar table(CarId int, Carname varchar(4' insert @SOtblCar select 14,'C4....
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I have the following many-to-many mapping:
public class Student implements { @Id @GeneratedValue private Integer xID;
@ManyToMany @JoinTable(name = "x_y", joinColumns = { @JoinColumn(name = "xID")}, inverseJoinColumns={@JoinColumn(name="yID")}) private...
Started by Benny on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
With cascading set up properly you can change your saving code to;
Entitymanager em = emf.createEntityManager(); em.getTransaction().begin(); Student... .
Try adding @ManyToMany(cascade = CascadeType.ALL) to your Cat object, to cascade your read operations .
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I have three tables as follows (please forgive the loose syntax), with NO cascading relationships (I do not want this, as the database is primarily managed by NHibernate).
Invoice ( entity_id int not null, ... ) Ticket ( entity_id int not null, ... ) ...
Started by Jon Seigel on
, 6 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
Finally blow away the temporary table.
You could put the rows from InvoiceTicket into a temporary table, and then delete InvoiceTicket, Ticket and finally Invoice from the ids in the temporary table.
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Still very much a newbie at Access, so apologies up front for the raw simplicity of this question.
I've got a main table TblMain and a junction table TblJunction with a one-to-one relationship.
I'm using TblMain as the form and TblJunction as a subform...
Started by dashingirish on
, 4 posts
by 3 people.
Answer Snippets (Read the full thread at access-programmers):
I'm, with a junction table....
Without knowing what's in tblMain or tblJunction or what you want to do isn't a true junction table which is normally used to facilitate a Many-to-Many relationship.
Isn't a junction table.
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Started by phpnetpro on
, 50 posts
by 32 people.
Answer Snippets (Read the full thread at warriorforum):
Thanks,
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