Errors now return constraint violations. 0.5.0

README.md

@@ -23,7 +23,7 @@ by adding `mssqlex` to your list of dependencies in `mix.exs`:
 
 ```elixir
 def deps do
-  [{:mssqlex, "~> 0.4"}]
+  [{:mssqlex, "~> 0.5"}]
 end
 ```
 

lib/mssqlex/error.ex

@@ -7,11 +7,12 @@ defmodule Mssqlex.Error do
     or the string representation of the code if it cannot be translated.
   """
 
-  defexception [:message, :odbc_code]
+  defexception [:message, :odbc_code, constraint_violations: []]
 
   @type t :: %__MODULE__{
     message: binary(),
-    odbc_code: atom() | binary()
+    odbc_code: atom() | binary(),
+    constraint_violations: Keyword.t
   }
 
   @not_allowed_in_transaction_messages [226, 574]
@@ -20,8 +21,9 @@ defmodule Mssqlex.Error do
   @spec exception(binary()) :: t()
   def exception({_, _, reason} = message) do
     %__MODULE__{
-      message: to_string(reason),
-      odbc_code: get_code(message)
+      message: to_string(to_string reason),
+      odbc_code: get_code(message),
+      constraint_violations: get_constraint_violations(to_string reason)
     }
   end
 
@@ -48,4 +50,18 @@ defmodule Mssqlex.Error do
   defp translate("42000"), do: :syntax_error_or_access_violation
   defp translate(code), do: code
 
+  defp get_constraint_violations(reason) do
+    constraint_checks =
+      [unique: ~r/Violation of UNIQUE KEY constraint '(\S+?)'./,
+       foreign_key: ~r/conflicted with the FOREIGN KEY constraint "(\S+?)"./,
+       check: ~r/conflicted with the CHECK constraint "(\S+?)"./]
+    extract = fn {key, test}, acc ->
+      case Regex.scan(test, reason, capture: :all_but_first) do
+        [] -> acc
+        matches -> Enum.reduce(matches, acc, fn [match], acc ->
+                     [{key, match} | acc] end)
+      end
+    end
+    Enum.reduce(constraint_checks, [], extract)
+  end
 end

mix.exs

@@ -3,7 +3,7 @@ defmodule Mssqlex.Mixfile do
 
   def project do
     [app: :mssqlex,
-     version: "0.4.5",
+     version: "0.5.0",
      description: "Adapter to Microsoft SQL Server. Using DBConnection and ODBC.",
      elixir: "~> 1.4",
      build_embedded: Mix.env == :prod,

test/mssqlex/constraints_test.exs

@@ -0,0 +1,70 @@
+defmodule Mssqlex.ConstraintsTest do
+  use ExUnit.Case, async: true
+
+  setup_all do
+    {:ok, pid} = Mssqlex.start_link([])
+    Mssqlex.query!(pid, "DROP DATABASE IF EXISTS constraints_test;", [])
+    {:ok, _, _} = Mssqlex.query(pid, "CREATE DATABASE constraints_test;", [])
+
+    {:ok, [pid: pid]}
+  end
+
+  test "Unique constraint", %{pid: pid} do
+    table_name = "constraints_test.dbo.uniq"
+    Mssqlex.query!(pid, """
+      CREATE TABLE #{table_name}
+      (id int CONSTRAINT id_unique UNIQUE)
+    """, [])
+    Mssqlex.query!(pid, "INSERT INTO #{table_name} VALUES (?)", [42])
+    error = assert_raise Mssqlex.Error, fn ->
+      Mssqlex.query!(pid, "INSERT INTO #{table_name} VALUES (?)", [42])
+    end
+    assert error.constraint_violations == [unique: "id_unique"]
+  end
+
+  test "Foreign Key constraint", %{pid: pid} do
+    assoc_table_name = "constraints_test.dbo.assoc"
+    table_name = "constraints_test.dbo.fk"
+    Mssqlex.query!(pid, """
+    CREATE TABLE #{assoc_table_name}
+    (id int CONSTRAINT id_pk PRIMARY KEY)
+    """, [])
+    Mssqlex.query!(pid, """
+    CREATE TABLE #{table_name}
+    (id int CONSTRAINT id_foreign FOREIGN KEY REFERENCES #{assoc_table_name})
+    """, [])
+    Mssqlex.query!(pid, "INSERT INTO #{assoc_table_name} VALUES (?)", [42])
+    error = assert_raise Mssqlex.Error, fn ->
+      Mssqlex.query!(pid, "INSERT INTO #{table_name} VALUES (?)", [12])
+    end
+    assert error.constraint_violations == [foreign_key: "id_foreign"]
+  end
+
+  test "Check constraint", %{pid: pid} do
+    table_name = "constraints_test.dbo.chk"
+    Mssqlex.query!(pid, """
+    CREATE TABLE #{table_name}
+    (id int CONSTRAINT id_check CHECK (id = 1))
+    """, [])
+    error = assert_raise Mssqlex.Error, fn ->
+      Mssqlex.query!(pid, "INSERT INTO #{table_name} VALUES (?)", [42])
+    end
+    assert error.constraint_violations == [check: "id_check"]
+  end
+
+  @tag skip: "Database doesn't support this"
+  test "Multiple constraints", %{pid: pid} do
+    table_name = "constraints_test.dbo.mult"
+    Mssqlex.query!(pid, """
+    CREATE TABLE #{table_name}
+    (id int CONSTRAINT id_unique UNIQUE,
+     foo int CONSTRAINT foo_check CHECK (foo = 3))
+    """, [])
+    Mssqlex.query!(pid, "INSERT INTO #{table_name} VALUES (?, ?)", [42, 3])
+    error = assert_raise Mssqlex.Error, fn ->
+      Mssqlex.query!(pid, "INSERT INTO #{table_name} VALUES (?, ?)", [42, 5])
+    end
+    assert error.constraint_violations == [unique: "id_unique", check: "foo_check"]
+  end
+
+end

test/mssqlex/types_test.exs

@@ -1,6 +1,5 @@
 defmodule Mssqlex.TypesTest do
   use ExUnit.Case, async: true
-  @moduletag :only
 
   alias Mssqlex.Result