Uses Ch as driver.
defp deps do
[
{:ecto_ch, "~> 0.4.0"}
]
endIn your config/config.exs
config :my_app, ecto_repos: [MyApp.Repo]
config :my_app, MyApp.Repo, url: "http://username:password@localhost:8123/database"In your application code
defmodule MyApp.Repo do
use Ecto.Repo,
otp_app: :my_app,
adapter: Ecto.Adapters.ClickHouse
endOptionally you can also set the default table engine and options to use in migrations
config :ecto_ch,
default_table_engine: "TinyLog",
default_table_options: [cluster: "little-giant", order_by: "tuple()"]For automatic RowBinary encoding please use the custom Ch Ecto type:
defmodule MyApp.Example do
use Ecto.Schema
@primary_key false
schema "example" do
field :number, Ch, type: "UInt32"
field :name, Ch, type: "String"
field :maybe_name, Ch, type: "Nullable(String)"
field :country_code, Ch, type: "FixedString(2)"
field :price, Ch, type: "Decimal32(2)"
field :map, Ch, type: "Map(String, UInt64)"
field :ipv4, Ch, type: "IPv4"
field :ipv4s, {:array, Ch}, type: "IPv4"
field :enum, Ch, type: "Enum8('hello' = 1, 'world' = 2)"
# etc.
end
end
MyApp.Repo.insert_all(MyApp.Example, rows)Some Ecto types like :string, :date, and Ecto.UUID would also work. Others like :decimal, :integer are ambiguous and should not be used.
ecto.ch.schema mix task can be used to generate a schema from an existing ClickHouse table.
For schemaless inserts :types option with a mapping of field->type needs to be provided:
types = [
number: "UInt32",
# or `number: :u32`
# or `number: Ch.Types.u32()`
# etc.
]
MyApp.Repo.insert_all("example", rows, types: types):settings option can be used to enable asynchronous inserts, lightweight deletes, global FINAL modifier, and more:
MyApp.Repo.insert_all(MyApp.Example, rows, settings: [async_insert: 1])
MyApp.Repo.delete_all("example", settings: [allow_experimental_lightweight_delete: 1])
MyApp.Repo.all(MyApp.AggregatedExample, settings: [final: 1])ClickHouse-specific options can be passed into table.options and index.options
table_options = [cluster: "my-cluster"]
engine_options = [order_by: "tuple()"]
options = table_options ++ engine_options
create table(:posts, primary_key: false, engine: "ReplicatedMergeTree", options: options) do
add :message, :string
add :user_id, :UInt64
endis equivalent to
CREATE TABLE `posts` ON CLUSTER `my-cluster` (
`message` String,
`user_id` UInt64
) ENGINE ReplicatedMergeTree ORDER BY tuple()ClickHouse doesn't support UPDATE statements as of now, so Repo.update/2 and Repo.update_all/3 raise when called. But Repo.alter_update_all/3 -- which executes ALTER TABLE ... UPDATE -- can be used instead.
Note that ALTER TABLE ... UPDATE is considered an admin operation and comes with a performance cost. Please read https://clickhouse.com/blog/handling-updates-and-deletes-in-clickhouse for more information.
For examples, please see clickhouse_alter_update_test.exs.
For ARRAY JOIN examples and other ClickHouse-specific JOIN types please see clickhouse_joins_test.exs.
DEFAULT expressions on columns are ignored when inserting RowBinary.