Improved query placeholders

.travis.yml

@@ -6,6 +6,7 @@ before_install:
   - unzip -d elixir v1.4.2.zip
 before_script:
   - export PATH=`pwd`/elixir/bin:$PATH
+  - mix local.rebar --force
   - mix local.hex --force
   - mix deps.get --only test
 script: mix test

lib/sql_dust.ex

@@ -14,8 +14,7 @@ defmodule SqlDust do
     options = %{
       select: ".*",
       adapter: :mysql,
-      initial_variables: options[:variables] || %{},
-      variables: %{},
+      variables: options[:variables] || %{},
       unique: false
     }
       |> Map.merge(options)
@@ -40,6 +39,33 @@ defmodule SqlDust do
       |> compose_sql
   end
 
+  def resolve_placeholders(placeholders, options, values \\ []) do
+    placeholders
+    |> Enum.with_index()
+    |> Enum.map(fn({path, index}) ->
+      case Regex.run(~r/option:(\w+)/, path) do
+        nil ->
+          String.split(path, ".") |> Enum.reduce(options.variables, fn(name, variables) ->
+            if is_map(variables) do
+              case MapUtils.get(variables, name) do
+                nil ->
+                  if Map.has_key?(variables, name) || Map.has_key?(variables, name |> String.to_atom()) do
+                    nil
+                  else
+                    Enum.at(values, index)
+                  end
+                value -> value
+              end
+            else
+              variables
+            end
+          end)
+        [_match, key] ->
+          options[String.to_atom(key)]
+      end
+    end)
+  end
+
   defp derive_select(options) do
     list = split_arguments(options[:select])
 
@@ -149,15 +175,15 @@ defmodule SqlDust do
 
   defp derive_limit(options) do
     if limit = MapUtils.get(options, :limit) do
-      options |> interpolate_option_variable(:limit, limit)
+      options |> put_option_placeholder(:limit, limit)
     else
       options
     end
   end
 
   defp derive_offset(options) do
     if offset = MapUtils.get(options, :offset) do
-      options |> interpolate_option_variable(:offset, offset)
+      options |> put_option_placeholder(:offset, offset)
     else
       options
     end
@@ -212,21 +238,15 @@ defmodule SqlDust do
     Map.put(options, key, prefix <> (conditions |> Enum.join(" AND ")))
   end
 
-  defp interpolate_option_variable(options, key, value) do
-    variables = options.variables
+  defp put_option_placeholder(options, key, value) do
+    interpolated_key = "option:" <> Atom.to_string(key)
 
     variables =
-      unless value == "?" do
-        option_variables = (options.variables[:_options_] || %{}) |> Map.put(key, value)
-        options.variables |> Map.put(:_options_, option_variables)
-      else
-        variables
-      end
-
-    interpolated_key = " <<_options_." <> Atom.to_string(key) <> ">>"
+      options.variables
+      |> Map.put(interpolated_key, value)
 
     options
-      |> Map.put(key, (Atom.to_string(key) |> String.upcase) <> interpolated_key)
+      |> Map.put(key, (Atom.to_string(key) |> String.replace("_", " ") |> String.upcase) <> " <<" <> interpolated_key <> ">>")
       |> Map.put(:variables, variables)
   end
 
@@ -248,6 +268,6 @@ defmodule SqlDust do
       |> List.flatten
       |> Enum.reject(&is_nil/1)
       |> Enum.join("\n")
-      |> interpolate_variables(options.variables, options.initial_variables)
+      |> interpolate_placeholders(options)
   end
 end

lib/sql_dust/utils/scan_utils.ex

@@ -1,7 +1,7 @@
 defmodule SqlDust.ScanUtils do
   alias SqlDust.MapUtils
 
-  @variable_regex ~r/<<([\w\.]+)>>/
+  @variable_regex ~r/<<((?:option:)?[\w\.]+)>>/
 
   def split_arguments(sql) when is_list(sql) do
     sql
@@ -126,11 +126,10 @@ defmodule SqlDust.ScanUtils do
     {String.replace(sql, "{#{index}}", pattern), index}
   end
 
-  def interpolate_variables(sql, variables, initial_variables) do
+  def interpolate_placeholders(sql, %{variables: variables}) do
     excluded = scan_strings(sql)
     sql = numerize_patterns(sql, excluded)
 
-
     {sql, values, keys} =
       @variable_regex
       |> Regex.scan(sql)
@@ -139,20 +138,7 @@ defmodule SqlDust.ScanUtils do
           MapUtils.get(variables, name)
         end)
 
-        anonymous_key =
-          Regex.match?(~r(__\d+__), key) || (
-            String.contains?(key, "_options_") && (
-              !(initial_variables
-              |> MapUtils.get(:_options_, %{})
-              |> Map.keys
-              |> Enum.map(fn
-                (k) when is_atom(k) -> Atom.to_string(k)
-                (k) -> k
-              end)
-              |> Enum.member?(String.split(key, ".", parts: 3) |> Enum.at(1)))
-            )
-          )
-
+        anonymous_key = Regex.match?(~r(__\d+__), key)
         sql = String.replace sql, match, "?", global: false
         values = [value | values]
         key = if anonymous_key, do: nil, else: key
@@ -164,10 +150,7 @@ defmodule SqlDust.ScanUtils do
     keys = Enum.reverse(keys)
 
     sql = interpolate_patterns(sql, excluded)
-    include_keys = Enum.any?(Map.keys(initial_variables), fn(key) ->
-      key = if is_atom(key), do: Atom.to_string(key), else: key
-      !Regex.match?(~r(__\d+__), key)
-    end)
+    include_keys = (length(keys) > 0) && !Enum.any?(keys, &is_nil/1)
 
     if include_keys do
       {sql, values, keys}

mix.exs

@@ -24,7 +24,7 @@ defmodule SqlDust.Mixfile do
       {:benchfella, "~> 0.3.0", only: :dev},
       {:earmark, "~> 0.1", only: :dev},
       {:ex_doc, "~> 0.11", only: :dev},
-      {:credo, "~> 0.2", only: [:dev, :test]},
+      {:credo, "~> 0.8", only: [:dev, :test]},
       {:inch_ex, ">= 0.0.0", only: :docs}
     ]
   end

mix.lock

@@ -1,13 +1,13 @@
-%{"benchfella": {:hex, :benchfella, "0.3.4", "41d2c017b361ece5225b5ba2e3b30ae53578c57c6ebc434417b4f1c2c94cf4f3", [:mix], []},
-  "bunt": {:hex, :bunt, "0.1.5", "c378ea1698232597d3778e4b83234dcea4a60e7c28114b0fe53657a2c0d8885e", [:mix], []},
-  "credo": {:hex, :credo, "0.3.13", "90d2d2deb9d376bb2a63f81126a320c3920ce65acb1294982ab49a8aacc7d89f", [:mix], [{:bunt, "~> 0.1.4", [hex: :bunt, optional: false]}]},
-  "decimal": {:hex, :decimal, "1.3.1", "157b3cedb2bfcb5359372a7766dd7a41091ad34578296e951f58a946fcab49c6", [:mix], []},
-  "earmark": {:hex, :earmark, "0.2.1", "ba6d26ceb16106d069b289df66751734802777a3cbb6787026dd800ffeb850f3", [:mix], []},
-  "ecto": {:hex, :ecto, "2.0.5", "7f4c79ac41ffba1a4c032b69d7045489f0069c256de606523c65d9f8188e502d", [:mix], [{:db_connection, "~> 1.0-rc.4", [hex: :db_connection, optional: true]}, {:decimal, "~> 1.1.2 or ~> 1.2", [hex: :decimal, optional: false]}, {:mariaex, "~> 0.7.7", [hex: :mariaex, optional: true]}, {:poison, "~> 1.5 or ~> 2.0", [hex: :poison, optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, optional: false]}, {:postgrex, "~> 0.12.0", [hex: :postgrex, optional: true]}, {:sbroker, "~> 1.0-beta", [hex: :sbroker, optional: true]}]},
-  "ex_doc": {:hex, :ex_doc, "0.11.4", "a064bdb720594c3745b94709b17ffb834fd858b4e0c1f48f37c0d92700759e02", [:mix], [{:earmark, "~> 0.1.17 or ~> 0.2", [hex: :earmark, optional: true]}]},
-  "exprintf": {:hex, :exprintf, "0.2.1", "b7e895dfb00520cfb7fc1671303b63b37dc3897c59be7cbf1ae62f766a8a0314", [:mix], []},
-  "exprof": {:hex, :exprof, "0.2.0", "b03f50d0d33e2f18c8e047d9188ba765dc32daba0b553ed717a98a78561d5eaf", [:mix], [{:exprintf, "~> 0.1", [hex: :exprintf, optional: false]}]},
-  "inch_ex": {:hex, :inch_ex, "0.5.1", "c1c18966c935944cbb2d273796b36e44fab3c54fd59f906ff026a686205b4e14", [:mix], [{:poison, "~> 1.5 or ~> 2.0", [hex: :poison, optional: false]}]},
-  "inflex": {:hex, :inflex, "1.6.0", "2c0c9928cd865e3b47cfaaa15c3520dfdb8c6ba5829d036296deb766f2aba770", [:mix], []},
-  "poison": {:hex, :poison, "2.2.0", "4763b69a8a77bd77d26f477d196428b741261a761257ff1cf92753a0d4d24a63", [:mix], []},
-  "poolboy": {:hex, :poolboy, "1.5.1", "6b46163901cfd0a1b43d692657ed9d7e599853b3b21b95ae5ae0a777cf9b6ca8", [:rebar], []}}
+%{"benchfella": {:hex, :benchfella, "0.3.4", "41d2c017b361ece5225b5ba2e3b30ae53578c57c6ebc434417b4f1c2c94cf4f3", [:mix], [], "hexpm"},
+  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
+  "credo": {:hex, :credo, "0.8.4", "4e50acac058cf6292d6066e5b0d03da5e1483702e1ccde39abba385c9f03ead4", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}], "hexpm"},
+  "decimal": {:hex, :decimal, "1.3.1", "157b3cedb2bfcb5359372a7766dd7a41091ad34578296e951f58a946fcab49c6", [:mix], [], "hexpm"},
+  "earmark": {:hex, :earmark, "0.2.1", "ba6d26ceb16106d069b289df66751734802777a3cbb6787026dd800ffeb850f3", [:mix], [], "hexpm"},
+  "ecto": {:hex, :ecto, "2.0.5", "7f4c79ac41ffba1a4c032b69d7045489f0069c256de606523c65d9f8188e502d", [:mix], [{:db_connection, "~> 1.0-rc.4", [hex: :db_connection, repo: "hexpm", optional: true]}, {:decimal, "~> 1.1.2 or ~> 1.2", [hex: :decimal, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.7.7", [hex: :mariaex, repo: "hexpm", optional: true]}, {:poison, "~> 1.5 or ~> 2.0", [hex: :poison, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.12.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0-beta", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
+  "ex_doc": {:hex, :ex_doc, "0.11.4", "a064bdb720594c3745b94709b17ffb834fd858b4e0c1f48f37c0d92700759e02", [:mix], [{:earmark, "~> 0.1.17 or ~> 0.2", [hex: :earmark, repo: "hexpm", optional: true]}], "hexpm"},
+  "exprintf": {:hex, :exprintf, "0.2.1", "b7e895dfb00520cfb7fc1671303b63b37dc3897c59be7cbf1ae62f766a8a0314", [:mix], [], "hexpm"},
+  "exprof": {:hex, :exprof, "0.2.0", "b03f50d0d33e2f18c8e047d9188ba765dc32daba0b553ed717a98a78561d5eaf", [:mix], [{:exprintf, "~> 0.1", [hex: :exprintf, repo: "hexpm", optional: false]}], "hexpm"},
+  "inch_ex": {:hex, :inch_ex, "0.5.1", "c1c18966c935944cbb2d273796b36e44fab3c54fd59f906ff026a686205b4e14", [:mix], [{:poison, "~> 1.5 or ~> 2.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
+  "inflex": {:hex, :inflex, "1.6.0", "2c0c9928cd865e3b47cfaaa15c3520dfdb8c6ba5829d036296deb766f2aba770", [:mix], [], "hexpm"},
+  "poison": {:hex, :poison, "2.2.0", "4763b69a8a77bd77d26f477d196428b741261a761257ff1cf92753a0d4d24a63", [:mix], [], "hexpm"},
+  "poolboy": {:hex, :poolboy, "1.5.1", "6b46163901cfd0a1b43d692657ed9d7e599853b3b21b95ae5ae0a777cf9b6ca8", [:rebar], [], "hexpm"}}

test/sql_dust_test.exs

@@ -599,61 +599,70 @@ defmodule SqlDustTest do
       SELECT `u`.*
       FROM `users` `u`
       LIMIT ?
-      """, [20]}
+      """,
+      [20],
+      ~w(option:limit)}
   end
 
-  test "limiting the query result by passing the limit in variables[:_options_][:limit]" do
+  test "adding an offset to the query result" do
     options = %{
-      limit: "?",
-      variables: %{
-        _options_: %{
-          limit: 20
-        }
-      }
+      limit: 10,
+      offset: 20
     }
 
     assert SqlDust.from("users", options) == {"""
       SELECT `u`.*
       FROM `users` `u`
       LIMIT ?
+      OFFSET ?
       """,
-      [20],
-      ~w(_options_.limit)}
+      [10, 20],
+      ~w(option:limit option:offset)}
   end
 
-  test "adding an offset to the query result" do
+  test "resolving placeholders" do
+    placeholders =
+      ~w(person.first_name person.last_name person.last_name option:limit option:offset epic)
+
     options = %{
+      variables: %{
+        person: %{
+          first_name: "Paul",
+          last_name: "Engel"
+        },
+        awesome: true
+      },
       limit: 10,
       offset: 20
     }
 
-    assert SqlDust.from("users", options) == {"""
-      SELECT `u`.*
-      FROM `users` `u`
-      LIMIT ?
-      OFFSET ?
-      """, [10, 20]}
+    assert SqlDust.resolve_placeholders(placeholders, options) == [
+      "Paul", "Engel", "Engel", 10, 20, nil
+    ]
   end
 
-  test "adding an offset to the query result by passing the offset in variables[:_options_][:offset]" do
+  test "resolving placeholders (with fallback to static values)" do
+    placeholders =
+      ~w(person.first_name person.last_name person.last_name awesome option:limit option:offset)
+
     options = %{
-      limit: 10,
-      offset: "?",
       variables: %{
-        _options_: %{
-          offset: 20
-        }
-      }
+        person: %{
+          last_name: "Engel"
+        },
+        awesome: nil
+      },
+      limit: 10,
+      offset: 20
     }
 
-    assert SqlDust.from("users", options) == {"""
-      SELECT `u`.*
-      FROM `users` `u`
-      LIMIT ?
-      OFFSET ?
-      """,
-      [10, 20],
-      [nil, "_options_.offset"]}
+    values = [
+      "Ken", "Engel", "Engel", true, 10, 20
+    ]
+
+    assert SqlDust.resolve_placeholders(placeholders, options, values) == [
+      "Ken", "Engel", "Engel", nil, 10, 20
+    ]
   end
 
   test "quoting SELECT statement aliases" do
@@ -891,7 +900,9 @@ defmodule SqlDustTest do
       HAVING (`order.count` > 5)
       ORDER BY COUNT(DISTINCT `tags`.`id`) DESC
       LIMIT ?
-      """, [5]}
+      """,
+      [5],
+      ~w(option:limit)}
   end
 
   test "DirectiveRecord example 3" do