Add a query struct for managing query data

CHANGELOG.md

@@ -7,9 +7,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## Breaking
+
+- add `Snowflex.Query` as the way to create queries and pass data.
+- remove `Snowflex.sql_query` and `Snowflex.param_query` in favor of using a single `Snowflex.do_query` function that uses the new `Snowflex.Query`.
+
+## Added
+
+- `Snowflex.Connection.execute` now accepts a keyword list of options to override `Snowflex.Connection`-level options on a per query basis.
+- Updated deps
+
 ## [0.3.2] - 2021-06-02
 
 ### Added
+
 - Added `map_nulls_to_nil?` variable to connection configuration to allow conversion of `:null` values to `:nil` in snowflake query response
 
 ## [0.3.1] - 2021-03-10

README.md

@@ -78,6 +78,24 @@ def MyApp.Application do
 end
 ```
 
+## Usage
+
+In order to execute queries, you will need to create a `Snowflex.Query` struct and pass it to your execute function. It would look something like this for a static query.
+
+```elixir
+{:ok, query} = Snowflex.Query.create(%{query_string: "SELECT * FROM my_table"})
+MyApp.SnowflakeConnection.execute(query)
+```
+
+The `Query.create/1` function will also attempt to cast your SQL params.
+
+```elixir
+# This will cast the params to [{:sql_integer, 1}]
+{:ok, query} = Snowflex.Query.create(%{query_string: "SELECT * FROM my_table WHERE id = ?", params: [1]})
+
+MyApp.SnowflakeConnection.execute(query)
+```
+
 ## Caveats
 
 If you are planning to connect to the Snowflake warehouse, your local Erlang instance

lib/snowflex.ex

@@ -1,13 +1,13 @@
 defmodule Snowflex do
   @moduledoc """
-  The client interface for connecting to the Snowflake data warehouse.
+  The client interface for connecting to the Snowflake data warehouse. This module should not be used directly except for the types. The preferred method is to use a `Snowflex.Connection` to manage all query executions.
 
-  The main entry point to this module is `Snowflex.sql_query`. This function takes a string containing
+  The main entry point to this module is `Snowflex.do_query`. This function takes a `Snowflex.Query` struct containing
   a SQL query and returns a list of maps (one per row). NOTE: due to the way the Erlang ODBC works, all values comeback
   as strings. You will need to cast values appropriately.
   """
   alias Ecto.Changeset
-  alias Snowflex.Worker
+  alias Snowflex.{Worker, Query}
 
   # Shamelessly copied from http://erlang.org/doc/man/odbc.html#common-data-types-
   @type precision :: integer()
@@ -34,31 +34,29 @@ defmodule Snowflex do
 
   @type query_param :: {odbc_data_type(), [value()]}
   @type sql_data :: list(%{optional(String.t()) => String.t()})
-  @type query_opts :: [timeout: timeout(), map_null_to_nil?: boolean()]
+  @type connection_opts :: [timeout: timeout(), map_null_to_nil?: boolean()]
 
-  @spec sql_query(atom(), String.t(), query_opts()) ::
+  @spec do_query(pool_name :: atom(), query :: Query.t(), connection_opts()) ::
           sql_data() | {:error, term()}
-  def sql_query(pool_name, query, opts) do
+  def do_query(pool_name, query = %Query{params: nil}, opts) do
     timeout = Keyword.get(opts, :timeout)
 
     case :poolboy.transaction(
            pool_name,
-           &Worker.sql_query(&1, query, timeout),
+           &Worker.sql_query(&1, query.query_string, timeout),
            timeout
          ) do
       {:ok, results} -> process_results(results, opts)
       err -> err
     end
   end
 
-  @spec param_query(atom(), String.t(), list(query_param()), query_opts()) ::
-          sql_data() | {:error, term()}
-  def param_query(pool_name, query, params, opts) do
+  def do_query(pool_name, query = %Query{}, opts) do
     timeout = Keyword.get(opts, :timeout)
 
     case :poolboy.transaction(
            pool_name,
-           &Worker.param_query(&1, query, params, timeout),
+           &Worker.param_query(&1, query.query_string, query.params, timeout),
            timeout
          ) do
       {:ok, results} -> process_results(results, opts)
@@ -70,9 +68,6 @@ defmodule Snowflex do
     Enum.map(data, &cast_row(&1, schema))
   end
 
-  def int_param(val), do: {:sql_integer, val}
-  def string_param(val, length \\ 250), do: {{:sql_varchar, length}, val}
-
   # Helpers
 
   defp process_results(data, opts) when is_list(data) do

lib/snowflex/connection.ex

@@ -15,7 +15,8 @@ defmodule Snowflex.Connection do
     use Snowflex.Connection,
       otp_app: :my_app,
       timeout: :timer.seconds(60),
-      keep_alive?: true
+      keep_alive?: true,
+      map_nulls_to_nil?: true
   end
   ```
 
@@ -67,19 +68,27 @@ defmodule Snowflex.Connection do
 
   `execute/1`
   ```
-  query = "SELECT * FROM foo"
+  {:ok, query} = Snowflex.Query.create(%{query_string: "SELECT * FROM foo"})
 
   SnowflakeConnection.execute(query)
-  ```
 
-  `execute/2`
-  ```
-  query = \"""
+  # or with parameters
+
+  query_string = \"""
     SELECT * FROM foo
     WHERE bar = ?
   \"""
 
-  SnowflakeConnection.execute(query, [Snowflex.string_param("baz")])
+  {:ok, query} = Snowflex.Query.create(%{query_string: query_string, params: ["baz"]})
+  SnowflakeConnection.execute(query)
+  ```
+
+  You may also override any Connection-level options on each execute.
+
+  ```
+  {:ok, query} = Snowflex.Query.create(%{query_string: "SELECT * FROM foo"})
+
+  SnowflakeConnection.execute(query, timeout: :timer.minutes(1))
   ```
   """
 
@@ -102,7 +111,7 @@ defmodule Snowflex.Connection do
       ]
       @keep_alive? keep_alive?
       @heartbeat_interval :timer.hours(3)
-      @query_opts [
+      @default_connection_opts [
         timeout: timeout,
         map_nulls_to_nil?: map_nulls_to_nil?
       ]
@@ -133,27 +142,18 @@ defmodule Snowflex.Connection do
       end
 
       @impl Snowflex.Connection
-      def execute(query) when is_binary(query) do
-        Snowflex.sql_query(@name, query, @query_opts)
-      end
-
-      @impl Snowflex.Connection
-      def execute(query, params) when is_binary(query) and is_list(params) do
-        Snowflex.param_query(@name, query, params, @query_opts)
+      def execute(query = %Snowflex.Query{}, connection_opts \\ []) do
+        connection_opts = Keyword.merge(@default_connection_opts, connection_opts)
+        Snowflex.do_query(@name, query, connection_opts)
       end
     end
   end
 
   ## Callbacks
 
   @doc """
-  Wraps `Snowflex.sql_query/3` and injects the relevant information from the connection
-  """
-  @callback execute(query :: String.t()) :: Snowflex.sql_data() | {:error, any}
-
-  @doc """
-  Wraps `Snowflex.param_query/4` and injects the relevant information from the connection
+  Wraps `Snowflex.do_query/3` and injects the relevant information from the connection
   """
-  @callback execute(query :: String.t(), params :: list(Snowflex.query_param())) ::
+  @callback execute(query :: Snowflex.Query.t(), connection_opts :: Snowflex.connection_opts()) ::
               Snowflex.sql_data() | {:error, any}
 end

lib/snowflex/query.ex

@@ -0,0 +1,49 @@
+defmodule Snowflex.Query do
+  @moduledoc """
+  The module creates a structured data type for queries for easier execution.
+  """
+
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  alias Snowflex.Types.SQLParam
+
+  @type query_attrs :: %{
+          query_string: String.t(),
+          params: nil | list()
+        }
+
+  @required_fields ~w(query_string)a
+  @fields @required_fields ++ ~w(params)a
+
+  @primary_key false
+  embedded_schema do
+    field(:query_string, :string)
+    field(:params, {:array, SQLParam})
+  end
+
+  @doc """
+  Build a new Snowflex.Query struct
+  """
+  @spec create(attrs :: query_attrs()) :: {:ok, %__MODULE__{}} | {:error, Ecto.Changeset.t()}
+  def create(attrs) do
+    %__MODULE__{}
+    |> cast(attrs, @fields)
+    |> validate_required(@required_fields)
+    |> case do
+      changeset = %Ecto.Changeset{valid?: true} ->
+        query = apply_changes(changeset)
+        params = dump_params(query.params)
+
+        {:ok, %__MODULE__{query | params: params}}
+
+      changeset ->
+        {:error, changeset}
+    end
+  end
+
+  # HELPERS
+
+  defp dump_params(nil), do: nil
+  defp dump_params(params), do: Enum.flat_map(params, &Map.to_list/1)
+end

lib/snowflex/types/sql_param.ex

@@ -0,0 +1,21 @@
+defmodule Snowflex.Types.SQLParam do
+  @moduledoc """
+  Ecto.Type to cast params into odbc acceptable params
+  """
+  use Ecto.Type
+
+  @impl true
+  def type, do: :map
+
+  @impl true
+  def cast(term) when is_binary(term), do: {:ok, %{{:sql_varchar, 250} => term}}
+  def cast(term) when is_integer(term), do: {:ok, %{sql_integer: term}}
+  def cast(term = %Date{}), do: {:ok, %{{:sql_varchar, 250} => Date.to_iso8601(term)}}
+  def cast(_term), do: :error
+
+  @impl true
+  def load(term), do: {:ok, term}
+
+  @impl true
+  def dump(term), do: {:ok, term}
+end

mix.lock

@@ -3,14 +3,15 @@
   "decimal": {:hex, :decimal, "2.0.0", "a78296e617b0f5dd4c6caf57c714431347912ffb1d0842e998e9792b5642d697", [:mix], [], "hexpm", "34666e9c55dea81013e77d9d87370fe6cb6291d1ef32f46a1600230b1d44f577"},
   "dialyxir": {:hex, :dialyxir, "1.1.0", "c5aab0d6e71e5522e77beff7ba9e08f8e02bad90dfbeffae60eaf0cb47e29488", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "07ea8e49c45f15264ebe6d5b93799d4dd56a44036cf42d0ad9c960bc266c0b9a"},
   "earmark": {:hex, :earmark, "1.4.3", "364ca2e9710f6bff494117dbbd53880d84bebb692dafc3a78eb50aa3183f2bfd", [:mix], [], "hexpm", "8cf8a291ebf1c7b9539e3cddb19e9cef066c2441b1640f13c34c1d3cfc825fec"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.10", "6603d7a603b9c18d3d20db69921527f82ef09990885ed7525003c7fe7dc86c56", [:mix], [], "hexpm", "8e2d5370b732385db2c9b22215c3f59c84ac7dda7ed7e544d7c459496ae519c0"},
-  "ecto": {:hex, :ecto, "3.5.5", "48219a991bb86daba6e38a1e64f8cea540cded58950ff38fbc8163e062281a07", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "98dd0e5e1de7f45beca6130d13116eae675db59adfa055fb79612406acf6f6f1"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.13", "0c98163e7d04a15feb62000e1a891489feb29f3d10cb57d4f845c405852bbef8", [:mix], [], "hexpm", "d602c26af3a0af43d2f2645613f65841657ad6efc9f0e361c3b6c06b578214ba"},
+  "ecto": {:hex, :ecto, "3.6.2", "efdf52acfc4ce29249bab5417415bd50abd62db7b0603b8bab0d7b996548c2bc", [:mix], [{:decimal, "~> 1.6 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "efad6dfb04e6f986b8a3047822b0f826d9affe8e4ebdd2aeedbfcb14fd48884e"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
-  "ex_doc": {:hex, :ex_doc, "0.23.0", "a069bc9b0bf8efe323ecde8c0d62afc13d308b1fa3d228b65bca5cf8703a529d", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm", "f5e2c4702468b2fd11b10d39416ddadd2fcdd173ba2a0285ebd92c39827a5a16"},
+  "ex_doc": {:hex, :ex_doc, "0.24.2", "e4c26603830c1a2286dae45f4412a4d1980e1e89dc779fcd0181ed1d5a05c8d9", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "e134e1d9e821b8d9e4244687fb2ace58d479b67b282de5158333b0d57c6fb7da"},
   "makeup": {:hex, :makeup, "1.0.5", "d5a830bc42c9800ce07dd97fa94669dfb93d3bf5fcf6ea7a0c67b2e0e4a7f26c", [:mix], [{:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cfa158c02d3f5c0c665d0af11512fed3fba0144cf1aadee0f2ce17747fba2ca9"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.15.0", "98312c9f0d3730fde4049985a1105da5155bfe5c11e47bdc7406d88e01e4219b", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.1", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "75ffa34ab1056b7e24844c90bfc62aaf6f3a37a15faa76b07bc5eba27e4a8b4a"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.15.1", "b5888c880d17d1cc3e598f05cdb5b5a91b7b17ac4eaf5f297cb697663a1094dd", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.1", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "db68c173234b07ab2a07f645a5acdc117b9f99d69ebf521821d89690ae6c6ec8"},
+  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
   "meck": {:hex, :meck, "0.9.2", "85ccbab053f1db86c7ca240e9fc718170ee5bda03810a6292b5306bf31bae5f5", [:rebar3], [], "hexpm", "81344f561357dc40a8344afa53767c32669153355b626ea9fcbc8da6b3045826"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.1.0", "3a6fca1550363552e54c216debb6a9e95bd8d32348938e13de5eda962c0d7f89", [:mix], [], "hexpm", "08eb32d66b706e913ff748f11694b17981c0b04a33ef470e33e11b3d3ac8f54b"},
   "poolboy": {:hex, :poolboy, "1.5.2", "392b007a1693a64540cead79830443abf5762f5d30cf50bc95cb2c1aaafa006b", [:rebar3], [], "hexpm", "dad79704ce5440f3d5a3681c8590b9dc25d1a561e8f5a9c995281012860901e3"},
-  "telemetry": {:hex, :telemetry, "0.4.2", "2808c992455e08d6177322f14d3bdb6b625fbcfd233a73505870d8738a2f4599", [:rebar3], [], "hexpm", "2d1419bd9dda6a206d7b5852179511722e2b18812310d304620c7bd92a13fcef"},
+  "telemetry": {:hex, :telemetry, "0.4.3", "a06428a514bdbc63293cd9a6263aad00ddeb66f608163bdec7c8995784080818", [:rebar3], [], "hexpm", "eb72b8365ffda5bed68a620d1da88525e326cb82a75ee61354fc24b844768041"},
 }

test/snowflex/connection_test.exs

@@ -1,6 +1,8 @@
 defmodule Snowflex.ConnectionTest do
   use ExUnit.Case, async: true
 
+  alias Snowflex.Query
+
   defmodule SnowflakeConnection do
     use Snowflex.Connection,
       otp_app: :snowflex
@@ -34,15 +36,19 @@ defmodule Snowflex.ConnectionTest do
     test "should execute a sql query" do
       start_supervised!(SnowflakeConnection)
 
-      assert [%{"col" => 1}, %{"col" => 2}] == SnowflakeConnection.execute("my query")
+      {:ok, query} = Query.create(%{query_string: "my query"})
+
+      assert [%{"col" => 1}, %{"col" => 2}] == SnowflakeConnection.execute(query)
     end
   end
 
   describe "execute/2" do
     test "should execute a param query" do
       start_supervised!(SnowflakeConnection)
 
-      assert [%{"col" => 1}, %{"col" => 2}] == SnowflakeConnection.execute("my query", [])
+      {:ok, query} = Query.create(%{query_string: "my query", params: []})
+
+      assert [%{"col" => 1}, %{"col" => 2}] == SnowflakeConnection.execute(query)
     end
   end
 end

test/snowflex/query_test.exs

@@ -0,0 +1,21 @@
+defmodule Snowflex.QueryTest do
+  use ExUnit.Case
+
+  alias Snowflex.Query
+
+  describe "create/1" do
+    test "should create a new Snowflex.Query with no params" do
+      assert {:ok, %Query{query_string: "my string", params: nil}} =
+               Query.create(%{query_string: "my string"})
+    end
+
+    test "should create a Snowflex.Query with params" do
+      assert {:ok, %Query{query_string: "my string", params: [{{:sql_varchar, 250}, "hi"}]}} =
+               Query.create(%{query_string: "my string", params: ["hi"]})
+    end
+
+    test "should return an error when missing params" do
+      assert {:error, %Ecto.Changeset{}} = Query.create(%{params: ["hi"]})
+    end
+  end
+end