How do you create a unique index on two columns in Ecto, which would correspond to this:
CREATE TABLE someTable (
col1 int NOT NULL,
col2 int NOT NULL,
primary key (col1, col2)
)
?
A Little follow up on Patrick's answer
Using only create unique_index on your model will ultimately throw an exception instead of giving you an error.
To get an error add a constraint on your changeset but as a paremeter you can give the index name created by unique_index.
So in your migration file :
create unique_index(:your_table, [:col1, :col2], name: :your_index_name)
Then in your changeset :
def changeset(model, param \\ :empty) do
model
|> cast(params, @required_fields, @optional_fields)
|> unique_constraint(:name_your_constraint, name: :your_index_name)
end