Top "Unique-constraint" questions

Unique-constraint is an index that sets one or multiple fields to be unique in a data entity

Hibernate - clearing a collection with all-delete-orphan and then adding to it causes ConstraintViolationException

I have these entities class Foo{ Set<Bar> bars; } class Bar{ Foo parent; String localIdentifier; } With this mapping (…

hibernate unique-constraint
Django UniqueConstraint

Context I have the models AppVersion, App & DeployApp. In the AppVersion model users can upload APK files to the …

python django unique-constraint
Hibernate throws unique constraint violation exception while updating field part of unique key

Below is the use case: I have a unique index defined on 3 columns say A,B,C. Assume the values …

java hibernate unique-constraint unique-index
Conditional unique constraint with multiple fields in oracle db

I have this table: XPTO_TABLE (id, obj_x, date_x, type_x, status_x) I wanna create a unique …

sql oracle conditional unique unique-constraint
Catching constraint violations in JPA 2.0

Consider the following entity class, used with, for example, EclipseLink 2.0.2 - where the link attribute is not the primary key, …

java jpa try-catch eclipselink unique-constraint
Does Entity Framework 5 support unique constraints?

Wondering if Entity Framework 5 supports unique constraints on entity properties? If so, how can I specify that a property should …

unique-constraint .net-4.5 entity-framework-5
How to define a "unique" constraint on a column of MySQL table in Ruby on Rails 3?

I have a simple MySQL table with one column: name. I would like to define a unique constraint on this …

mysql ruby-on-rails ruby-on-rails-3 unique unique-constraint
How can i make ruby on rails handle duplicate record errors from MySQL

I have a unique index on multiple fields on my database. So if you try to call save on a …

mysql ruby-on-rails ruby insert unique-constraint
Entity Framework: How to properly handle exceptions that occur due to SQL constraints

I use Entity Framework to access my SQL data. I have some constraints in the database schema and I wonder …

sql sql-server entity-framework constraints unique-constraint
Sqlite NULL and unique?

I noticed that I can have NULL values in columns that have the UNIQUE constraint: UNIQUE(col) Would that generate …

sql sqlite null unique unique-constraint