Adds support for generate truncate table queries.

lib/cassandrax/connection.ex

@@ -118,6 +118,8 @@ defmodule Cassandrax.Connection do
     ["DELETE FROM ", quote_table(keyspace, table), " WHERE " | filters]
   end
 
+  def truncate(keyspace, table), do: ["TRUNCATE TABLE ", quote_table(keyspace, table)]
+
   defp assemble_filters(filters) do
     intersperse_map(filters, " AND ", fn field ->
       field = field |> Atom.to_string() |> quote_name()

lib/cassandrax/keyspace.ex

@@ -95,6 +95,9 @@ defmodule Cassandrax.Keyspace do
       def delete!(struct, opts \\ []),
         do: Cassandrax.Keyspace.Schema.delete!(__MODULE__, struct, opts)
 
+      def truncate(struct),
+        do: Cassandrax.Keyspace.Schema.truncate(__MODULE__, struct)
+
       ## Queryable
 
       def all(queryable, opts \\ []),

lib/cassandrax/keyspace/schema.ex

@@ -53,6 +53,27 @@ defmodule Cassandrax.Keyspace.Schema do
     end
   end
 
+  @doc """
+  Implementation for `Cassandrax.Keyspace.truncate/2`.
+  """
+  def truncate(keyspace, struct) do
+    conn = keyspace.__conn__
+    changeset = Ecto.Changeset.change(struct.__struct__)
+    schema = changeset.data.__struct__
+    keyspace_name = keyspace.__keyspace__
+    table = schema.__schema__(:source)
+
+    statement = Cassandrax.Connection.truncate(keyspace_name, table)
+
+    case Cassandrax.cql(conn, statement) do
+      {:ok, results} ->
+        {:ok, results}
+
+      {:error, error} ->
+        {:error, error}
+    end
+  end
+
   @doc """
   Implementation for `Cassandrax.Keyspace.insert/2`.
   """

test/cassandrax/connection_test.exs

@@ -42,6 +42,7 @@ defmodule Cassandrax.ConnectionTest do
   end
 
   defp to_string({iodata, _values}), do: IO.iodata_to_binary(iodata)
+  defp to_string(iodata), do: IO.iodata_to_binary(iodata)
   defp all(queryable), do: Cassandrax.Connection.all(TestKeyspace, queryable) |> to_string()
 
   describe "all/2" do
@@ -152,4 +153,18 @@ defmodule Cassandrax.ConnectionTest do
       assert all(queryable) =~ ~r/WHERE \("id" < \?\)/
     end
   end
+
+  defp truncate(queryable) do
+    changeset = Ecto.Changeset.change(queryable.__struct__)
+    schema = changeset.data.__struct__
+    keyspace_name = TestKeyspace.__keyspace__()
+    table = schema.__schema__(:source)
+    Cassandrax.Connection.truncate(keyspace_name, table) |> to_string()
+  end
+
+  describe "truncate" do
+    test "successfully generate a truncate clause when passed a schema" do
+      assert truncate(TestSchema) =~ ~r/TRUNCATE TABLE "test_keyspace"."my_table"/
+    end
+  end
 end

test/cassandrax/keyspace_test.exs

@@ -542,6 +542,27 @@ defmodule Cassandrax.KeyspaceTest do
     end
   end
 
+  describe "truncate" do
+    setup do
+      [
+        first: fixture(TestData, id: "0", timestamp: "00:00", data: "0"),
+        second:
+          fixture(TestData,
+            id: "1",
+            timestamp: "01:00",
+            data: "1",
+            svalue: MapSet.new(["one", "another one"])
+          )
+      ]
+    end
+
+    test "truncates all records on the table" do
+      assert Enum.count(TestKeyspace.all(TestData)) == 2
+      assert {:ok, %Xandra.Void{}} = TestKeyspace.truncate(TestData)
+      assert Enum.count(TestKeyspace.all(TestData)) == 0
+    end
+  end
+
   describe "cql" do
     setup do
       [