Returns the adapter tied to the repository.

A callback invoked by adapters that logs the given action.

See Ecto.LogEntry for more information and Ecto.Repo module documentation on setting up your own loggers.

Calculate the given aggregate over the given field.

If the query has a limit, offset or distinct set, it will be automatically wrapped in a subquery in order to return the proper result.

Any preload or select in the query will be ignored in favor of the column being aggregated.

The aggregation will fail if any group_by field is set.

Options

See the “Shared options” section at the module documentation.

Examples

# Returns the number of visits per blog post
Repo.aggregate(Post, :avg, :visits)

# Returns the average number of visits for the top 10
query = from Post, limit: 10
Repo.aggregate(query, :avg, :visits)

Fetches all entries from the data store matching the given query.

May raise Ecto.QueryError if query validation fails.

Options

See the “Shared options” section at the module documentation.

Example

# Fetch all post titles
query = from p in Post,
     select: p.title
MyRepo.all(query)

Returns the adapter configuration stored in the :otp_app environment.

Deletes a struct using its primary key.

If the struct has no primary key, Ecto.NoPrimaryKeyFieldError will be raised.

It returns {:ok, struct} if the struct has been successfully deleted or {:error, changeset} if there was a validation or a known constraint error.

Options

See the “Shared options” section at the module documentation.

Example

post = MyRepo.get!(Post, 42)
case MyRepo.delete post do
  {:ok, struct}       -> # Deleted with success
  {:error, changeset} -> # Something went wrong
end

Same as delete/2 but returns the struct or raises if the changeset is invalid.

Deletes all entries matching the given query.

It returns a tuple containing the number of entries and any returned result as second element. If the database does not support RETURNING in DELETE statements or no return result was selected, the second element will be nil.

Options

• :returning - selects which fields to return. When true, returns all fields in the given struct. May be a list of fields, where a struct is still returned but only with the given fields. Or false, where nothing is returned (the default). This option is not supported by all databases.

See the “Shared options” section at the module documentation for remaining options.

Examples

MyRepo.delete_all(Post)

from(p in Post, where: p.id < 10) |> MyRepo.delete_all

Fetches a single struct from the data store where the primary key matches the given id.

Returns nil if no result was found. If the struct in the queryable has no or more than one primary key, it will raise an argument error.

Options

See the “Shared options” section at the module documentation.

Example

MyRepo.get(Post, 42)

Similar to get/3 but raises Ecto.NoResultsError if no record was found.

Options

See the “Shared options” section at the module documentation.

Example

MyRepo.get!(Post, 42)

Fetches a single result from the query.

Returns nil if no result was found.

Options

See the “Shared options” section at the module documentation.

Example

MyRepo.get_by(Post, title: "My post")

Similar to get_by/3 but raises Ecto.NoResultsError if no record was found.

Options

See the “Shared options” section at the module documentation.

Example

MyRepo.get_by!(Post, title: "My post")

Returns true if the current process is inside a transaction.

Examples

MyRepo.in_transaction?
#=> false

MyRepo.transaction(fn ->
  MyRepo.in_transaction? #=> true
end)

Inserts a struct or a changeset.

In case a struct is given, the struct is converted into a changeset with all non-nil fields as part of the changeset.

In case a changeset is given, the changes in the changeset are merged with the struct fields, and all of them are sent to the database.

It returns {:ok, struct} if the struct has been successfully inserted or {:error, changeset} if there was a validation or a known constraint error.

Options

See the “Shared options” section at the module documentation.

Example

case MyRepo.insert %Post{title: "Ecto is great"} do
  {:ok, struct}       -> # Inserted with success
  {:error, changeset} -> # Something went wrong
end

Same as insert/2 but returns the struct or raises if the changeset is invalid.

Inserts all entries into the repository.

It expects a schema (MyApp.User) or a source ("users" or {"prefix", "users"}) as the first argument. The second argument is a list of entries to be inserted, either as keyword lists or as maps.

When a schema is given, the values given will be properly dumped before being sent to the database. If the schema contains an autogenerated ID field, it will be handled either at the adapter or the storage layer. However any other autogenerated value, like timestamps, won’t be autogenerated when using c:insert_all/3. This is by design as this function aims to be a more direct way to insert data into the database without the conveniences of c:insert/2. This is also consistent with c:update_all/3 that does not handle timestamps as well.

If a source is given, without a schema, the given fields are passed as is to the adapter.

Options

See the “Shared options” section at the module documentation.

Inserts or updates a changeset depending on whether the struct is persisted or not.

The distinction whether to insert or update will be made on the Ecto.Schema.Metadata field :state. The :state is automatically set by Ecto when loading or building a schema.

Please note that for this to work, you will have to load existing structs from the database. So even if the struct exists, this won’t work:

struct = %Post{id: 'existing_id', ...}
MyRepo.insert_or_update changeset
# => {:error, "id already exists"}

Options

See the “Shared options” section at the module documentation.

Example

result =
  case MyRepo.get(Post, id) do
    nil  -> %Post{id: id} # Post not found, we build one
    post -> post          # Post exists, let's use it
  end
  |> Post.changeset(changes)
  |> MyRepo.insert_or_update

case result do
  {:ok, struct}       -> # Inserted or updated with success
  {:error, changeset} -> # Something went wrong
end

Same as insert_or_update/2 but returns the struct or raises if the changeset is invalid.

Fetches a single result from the query.

Returns nil if no result was found. Raises if more than one entry.

Options

See the “Shared options” section at the module documentation.

Similar to one/2 but raises Ecto.NoResultsError if no record was found.

Raises if more than one entry.

Options

See the “Shared options” section at the module documentation.

Preloads all associations on the given struct or structs.

This is similar to Ecto.Query.preload/3 except it allows you to preload structs after they have been fetched from the database.

In case the association was already loaded, preload won’t attempt to reload it.

Options

Besides the “Shared options” section at the module documentation, it accepts:

• :force - By default, Ecto won’t preload associations that are already loaded. By setting this option to true, any existing association will be discarded and reloaded.
• :in_parallel - If the preloads must be done in parallel. It can only be performed when we have more than one preload and the repository is not in a transaction. Defaults to true.
• :prefix - the prefix to fetch preloads from. By default, queries will use the same prefix as the one in the given collection. This option allows the prefix to be changed.

Examples

posts = Repo.preload posts, :comments
posts = Repo.preload posts, comments: :permalinks
posts = Repo.preload posts, comments: from(c in Comment, order_by: c.published_at)

Rolls back the current transaction.

The transaction will return the value given as {:error, value}.

Starts any connection pooling or supervision and return {:ok, pid} or just :ok if nothing needs to be done.

Returns {:error, {:already_started, pid}} if the repo is already started or {:error, term} in case anything else goes wrong.

Shuts down the repository represented by the given pid.

Runs the given function or Ecto.Multi inside a transaction.

Use with function

If an unhandled error occurs the transaction will be rolled back and the error will bubble up from the transaction function. If no error occurred the transaction will be committed when the function returns. A transaction can be explicitly rolled back by calling rollback/1, this will immediately leave the function and return the value given to rollback as {:error, value}.

A successful transaction returns the value returned by the function wrapped in a tuple as {:ok, value}.

If transaction/2 is called inside another transaction, the function is simply executed, without wrapping the new transaction call in any way. If there is an error in the inner transaction and the error is rescued, or the inner transaction is rolled back, the whole outer transaction is marked as tainted, guaranteeing nothing will be committed.

Use with Ecto.Multi

Besides functions transaction can be used with an Ecto.Multi struct. Transaction will be started, all operations applied and in case of success committed returning {:ok, changes}. In case of any errors the transaction will be rolled back and {:error, failed_operation, failed_value, changes_so_far} will be returned.

You can read more about using transactions with Ecto.Multi as well as see some examples in the Ecto.Multi documentation.

Options

See the “Shared options” section at the module documentation.

Examples

MyRepo.transaction(fn ->
  MyRepo.update!(%{alice | balance: alice.balance - 10})
  MyRepo.update!(%{bob | balance: bob.balance + 10})
end)

# Roll back a transaction explicitly
MyRepo.transaction(fn ->
  p = MyRepo.insert!(%Post{})
  if not Editor.post_allowed?(p) do
    MyRepo.rollback(:posting_not_allowed)
  end
end)

# With Ecto.Multi
Ecto.Multi.new
|> Ecto.Multi.insert(%Post{})
|> MyRepo.transaction

Updates a changeset using its primary key.

A changeset is required as it is the only for mechanism for tracking dirty changes.

If the struct has no primary key, Ecto.NoPrimaryKeyFieldError will be raised.

It returns {:ok, struct} if the struct has been successfully updated or {:error, changeset} if there was a validation or a known constraint error.

Options

Besides the “Shared options” section at the module documentation, it accepts:

• :force - By default, if there are no changes in the changeset, update!/2 is a no-op. By setting this option to true, update callbacks will always be executed, even if there are no changes (including timestamps).

Example

post = MyRepo.get!(Post, 42)
post = Ecto.Changeset.change post, title: "New title"
case MyRepo.update post do
  {:ok, struct}       -> # Updated with success
  {:error, changeset} -> # Something went wrong
end

Same as update/2 but returns the struct or raises if the changeset is invalid.

Updates all entries matching the given query with the given values.

It returns a tuple containing the number of entries and any returned result as second element. If the database does not support RETURNING in UPDATE statements or no return result was selected, the second element will be nil.

Keep in mind this update_all will not update autogenerated fields like the updated_at columns.

See Ecto.Query.update/3 for update operations that can be performed on fields.

Options

• :returning - selects which fields to return. When true, returns all fields in the given struct. May be a list of fields, where a struct is still returned but only with the given fields. Or false, where nothing is returned (the default). This option is not supported by all databases.

See the “Shared options” section at the module documentation for remaining options.

Examples

MyRepo.update_all(Post, set: [title: "New title"])

MyRepo.update_all(Post, inc: [visits: 1])

from(p in Post, where: p.id < 10)
|> MyRepo.update_all(set: [title: "New title"])

from(p in Post, where: p.id < 10, update: [set: [title: "New title"]])
|> MyRepo.update_all([])