GH-43183: [C++] Add date to date cast

apache · Jul 8, 2024 · 9c8a433 · 9c8a433
1 parent e8a795b
commit 9c8a433
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Showing 2 changed files with 20 additions and 2 deletions.
diff --git a/cpp/src/arrow/compute/kernels/scalar_cast_temporal.cc b/cpp/src/arrow/compute/kernels/scalar_cast_temporal.cc
@@ -510,9 +510,12 @@ void AddCrossUnitCastNoPreallocate(CastFunction* func) {
 
 std::shared_ptr<CastFunction> GetDate32Cast() {
   auto func = std::make_shared<CastFunction>("cast_date32", Type::DATE32);
-  auto out_ty = date32();
+  const auto& out_ty = date32();
   AddCommonCasts(Type::DATE32, out_ty, func.get());
 
+  // date32 -> date32
+  AddCrossUnitCast<Date32Type>(func.get());
+
   // int32 -> date32
   AddZeroCopyCast(Type::INT32, int32(), date32(), func.get());
 
@@ -532,9 +535,12 @@ std::shared_ptr<CastFunction> GetDate32Cast() {
 
 std::shared_ptr<CastFunction> GetDate64Cast() {
   auto func = std::make_shared<CastFunction>("cast_date64", Type::DATE64);
-  auto out_ty = date64();
+  const auto out_ty = date64();
   AddCommonCasts(Type::DATE64, out_ty, func.get());
 
+  // date64 -> date64
+  AddCrossUnitCast<Date64Type>(func.get());
+
   // int64 -> date64
   AddZeroCopyCast(Type::INT64, int64(), date64(), func.get());
 

diff --git a/python/pyarrow/tests/test_ipc.py b/python/pyarrow/tests/test_ipc.py
@@ -1199,6 +1199,18 @@ def make_batches():
         reader = pa.RecordBatchReader.from_batches(None, batches)
         pass
 
+    # https://github.com/apache/arrow/issues/43183
+    data = [[datetime.date(1990, 3, 1)]]
+    batch = pa.RecordBatch.from_arrays(data, names=['dates'])
+    schema = pa.schema([
+        ('dates', pa.date32()),
+    ])
+
+    assert pa.RecordBatchReader.from_batches(
+        schema,
+        [batch]
+    ).cast(schema).read_all() == [[data]]
+
 
 def test_record_batch_reader_from_arrow_stream():