unique-constraint

TL;DR: How do you save/validate multiple objects with a unique attribute using a formset? Let's say I have a Machine which has multiple Setting s (see models below). These settings should have a unique ordering within the machine. This can be accomplished by defining a unique_together attribute in the Meta class of the Setting model: unique_together = (('order', 'machine'), ) However, I'm using an inline formset to update all the Setting s of a Machine . Assume I have the following info in my formset: Setting 1: machine=1; order=1 Setting 2: machine=1; order=2 If I were to switch the order on

In my PostgreSQL 9.4 database, I have a table fields with a column name with unique values. I'm creating a new table fields_new with a similar structure (not important here) and a column name as well. I need a way to constraint name values to be inserted to the fields_new not to be present in fields.name . For example, if fields.name contains the values 'color' and 'length' , I need to prevent fields_new.name from containing 'color' or 'length' values. So, in other words I need to provide that the name columns in both tables do not have any duplicate values between them. And the constraint

I have the following table definition: CREATE TABLE [Car] ( CarID int NOT NULL PRIMARY KEY IDENTITY(1,1), FirstColorID int FOREIGN KEY REFERENCES Colors(ColorID), SecondColorID int FOREIGN KEY REFERENCES Colors(ColorID), UNIQUE(FirstColorID, SecondColorID) ) I want the two Color columns to be unique, regardless of the combination they appear in. E.g. attemping: INSERT INTO Car (FirstColorID, SecondColorID) VALUES (1, 2); --should succeed but then trying the same after that first record exists with the colors reversed should fail: INSERT INTO Car (FirstColorID, SecondColorID) VALUES (2, 1); -

I have two tables named players & matches in a Postgres DB as follows: CREATE TABLE players ( name text NOT NULL, id serial PRIMARY KEY ); CREATE TABLE matches ( winner int REFERENCES players (id), loser int REFERENCES players (id), -- to prevent rematch btw players CONSTRAINT unique_matches PRIMARY KEY (winner, loser) ); How can I ensure that only a unique combination of either (winner, loser) or (loser, winner) is used for matches primary key so that the matches table won't allow the insertion of: INSERT INTO matches VALUES (2, 1); If it already has a row containing VALUES (1, 2) like :

I have an entity with an unique constraint on 3 fiels. 2 fields are not nullable, and the third is nullable. My problem, when the third field is null, the unique constraint doesn't work, so i can have in my database some duplicate values like ( 5,1,null)(5,1,null) For me, ( 5,1,null) is an unique value, with null too. Do you have any ideas ? This is my ORM line : * @ORM\Table(name="table", uniqueConstraints={@ORM\UniqueConstraint(name="table_idx", columns={"field1", "field2", "field3"})}) Edit : The nullable value is a foreign key to an other entity, so i can't put a custom value. It's an

In my map I have: Component( x => x.ExposureKey, m => { m.Map(x => x.AsOfDate).Not.Nullable(); m.Map(x => x.ExposureId).Length(30).Not.Nullable(); } ).Unique(); The relevant output from the HBM is <component name="ExposureKey" insert="true" update="true" optimistic-lock="true" class="Some.Namespace.CreditExposureKey, Some.Namespace, Version=0.0.0.0, Culture=neutral, PublicKeyToken=aaaaaaaaaaaaaaaa"> <property name="AsOfDate" type="System.DateTime, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"> <column name="AsOfDate" not-null="true"/> </property> <property name=