OGRLayer::GetArrowStream(): add a DATETIME_AS_STRING=YES/NO option

apps/ogr2ogr_lib.cpp

@@ -3997,7 +3997,8 @@ static int GetArrowGeomFieldIndex(const struct ArrowSchema *psLayerSchema,
 /************************************************************************/
 
 static CPLStringList
-BuildGetArrowStreamOptions(const GDALVectorTranslateOptions *psOptions,
+BuildGetArrowStreamOptions(OGRLayer *poSrcLayer, OGRLayer *poDstLayer,
+                           const GDALVectorTranslateOptions *psOptions,
                            bool bPreserveFID)
 {
     CPLStringList aosOptionsGetArrowStream;
@@ -4021,6 +4022,31 @@ BuildGetArrowStreamOptions(const GDALVectorTranslateOptions *psOptions,
             "MAX_FEATURES_IN_BATCH",
             CPLSPrintf("%d", psOptions->nGroupTransactions));
     }
+
+    auto poSrcDS = poSrcLayer->GetDataset();
+    auto poDstDS = poDstLayer->GetDataset();
+    if (poSrcDS && poDstDS)
+    {
+        auto poSrcDriver = poSrcDS->GetDriver();
+        auto poDstDriver = poDstDS->GetDriver();
+
+        const auto IsArrowNativeDriver = [](GDALDriver *poDriver)
+        {
+            return EQUAL(poDriver->GetDescription(), "ARROW") ||
+                   EQUAL(poDriver->GetDescription(), "PARQUET") ||
+                   EQUAL(poDriver->GetDescription(), "ADBC");
+        };
+
+        if (poSrcDriver && poDstDriver && !IsArrowNativeDriver(poSrcDriver) &&
+            !IsArrowNativeDriver(poDstDriver))
+        {
+            // For non-Arrow-native drivers, request DateTime as string, to
+            // allow mix of timezones
+            aosOptionsGetArrowStream.SetNameValue(GAS_OPT_DATETIME_AS_STRING,
+                                                  "YES");
+        }
+    }
+
     return aosOptionsGetArrowStream;
 }
 
@@ -4085,8 +4111,8 @@ bool SetupTargetLayer::CanUseWriteArrowBatch(
             }
         }
 
-        const CPLStringList aosGetArrowStreamOptions(
-            BuildGetArrowStreamOptions(psOptions, bPreserveFID));
+        const CPLStringList aosGetArrowStreamOptions(BuildGetArrowStreamOptions(
+            poSrcLayer, poDstLayer, psOptions, bPreserveFID));
         if (poSrcLayer->GetArrowStream(streamSrc.get(),
                                        aosGetArrowStreamOptions.List()))
         {

autotest/cpp/CMakeLists.txt

@@ -108,7 +108,7 @@ gdal_standard_includes(gdal_unit_test)
 target_compile_options(gdal_unit_test PRIVATE ${GDAL_CXX_WARNING_FLAGS})
 target_compile_definitions(gdal_unit_test PRIVATE -DGDAL_TEST_ROOT_DIR="${GDAL_ROOT_TEST_DIR}")
 target_include_directories(
-  gdal_unit_test PRIVATE $<TARGET_PROPERTY:appslib,SOURCE_DIR> $<TARGET_PROPERTY:gdal_vrt,SOURCE_DIR>)
+  gdal_unit_test PRIVATE $<TARGET_PROPERTY:appslib,SOURCE_DIR> $<TARGET_PROPERTY:gdal_vrt,SOURCE_DIR> $<TARGET_PROPERTY:ogrsf_generic,SOURCE_DIR>)
 if (GDAL_USE_SQLITE3)
   target_compile_definitions(gdal_unit_test PRIVATE -DHAVE_SQLITE3)
   target_include_directories(

autotest/cpp/test_ogr.cpp

@@ -16,6 +16,7 @@
 #include "ogrsf_frmts.h"
 #include "../../ogr/ogrsf_frmts/osm/gpb.h"
 #include "ogr_recordbatch.h"
+#include "ogrlayerarrow.h"
 
 #include <string>
 #include <algorithm>
@@ -4444,4 +4445,43 @@ TEST_F(test_ogr, OGRFeature_SetGeomField)
     poFeatureDefn->Release();
 }
 
+TEST_F(test_ogr, GetArrowStream_DateTime_As_String)
+{
+    auto poDS = std::unique_ptr<GDALDataset>(
+        GetGDALDriverManager()->GetDriverByName("Memory")->Create(
+            "", 0, 0, 0, GDT_Unknown, nullptr));
+    auto poLayer = poDS->CreateLayer("test", nullptr, wkbNone);
+    OGRFieldDefn oFieldDefn("dt", OFTDateTime);
+    poLayer->CreateField(&oFieldDefn);
+    struct ArrowArrayStream stream;
+    CPLStringList aosOptions;
+    aosOptions.SetNameValue("INCLUDE_FID", "NO");
+    aosOptions.SetNameValue("DATETIME_AS_STRING", "YES");
+    ASSERT_TRUE(poLayer->GetArrowStream(&stream, aosOptions.List()));
+    struct ArrowSchema schema;
+    memset(&schema, 0, sizeof(schema));
+    EXPECT_EQ(stream.get_schema(&stream, &schema), 0);
+    EXPECT_TRUE(schema.n_children == 1 &&
+                strcmp(schema.children[0]->format, "u") == 0)
+        << schema.n_children;
+    if (schema.n_children == 1 && strcmp(schema.children[0]->format, "u") == 0)
+    {
+        EXPECT_TRUE(schema.children[0]->metadata != nullptr);
+        if (schema.children[0]->metadata)
+        {
+            auto oMapKeyValue =
+                OGRParseArrowMetadata(schema.children[0]->metadata);
+            EXPECT_EQ(oMapKeyValue.size(), 1);
+            if (oMapKeyValue.size() == 1)
+            {
+                EXPECT_STREQ(oMapKeyValue.begin()->first.c_str(),
+                             "GDAL:OGR:type");
+                EXPECT_STREQ(oMapKeyValue.begin()->second.c_str(), "DateTime");
+            }
+        }
+    }
+    schema.release(&schema);
+    stream.release(&stream);
+}
+
 }  // namespace

autotest/ogr/ogr_adbc.py

@@ -326,6 +326,36 @@ def test_ogr_adbc_test_ogrsf_parquet_filename_with_glob():
     assert "ERROR" not in ret
 
 
+###############################################################################
+# Test DATETIME_AS_STRING=YES GetArrowStream() option
+
+
+def test_ogr_adbc_arrow_stream_numpy_datetime_as_string(tmp_vsimem):
+    pytest.importorskip("osgeo.gdal_array")
+    pytest.importorskip("numpy")
+
+    if not _has_libduckdb():
+        pytest.skip("libduckdb.so missing")
+
+    with gdal.OpenEx(
+        "data/parquet/test.parquet", gdal.OF_VECTOR, allowed_drivers=["ADBC"]
+    ) as ds:
+        lyr = ds.GetLayer(0)
+        stream = lyr.GetArrowStreamAsNumPy(
+            options=["USE_MASKED_ARRAYS=NO", "DATETIME_AS_STRING=YES"]
+        )
+        batches = [batch for batch in stream]
+        batch = batches[0]
+        # Should be "2019-01-01T14:00:00.500-02:15" but DuckDB returns in UTC
+        # On my machine, for some reason it returns without the Z, whereas on
+        # the ubuntu_2404 it returns with the Z... despite both using libduckdb 1.1.3
+        # at time of writing...
+        assert batch["timestamp_ms_gmt_minus_0215"][0] in (
+            b"2019-01-01T16:15:00.500",
+            b"2019-01-01T16:15:00.500Z",
+        )
+
+
 ###############################################################################
 # Run test_ogrsf on a DuckDB dataset
 

autotest/ogr/ogr_flatgeobuf.py

@@ -1564,3 +1564,52 @@ def test_ogr_flatgeobuf_sql_arrow(tmp_vsimem):
             assert f["bar"] == "baz"
             assert f.GetGeometryRef().ExportToWkt() == "POINT (1 2)"
             f = tmp_lyr.GetNextFeature()
+
+
+###############################################################################
+# Test DATETIME_AS_STRING=YES GetArrowStream() option
+
+
+def test_ogr_flatgeobuf_arrow_stream_numpy_datetime_as_string(tmp_vsimem):
+    pytest.importorskip("osgeo.gdal_array")
+    pytest.importorskip("numpy")
+
+    filename = str(tmp_vsimem / "datetime_as_string.fgb")
+    with ogr.GetDriverByName("FlatGeoBuf").CreateDataSource(filename) as ds:
+        lyr = ds.CreateLayer("test")
+
+        field = ogr.FieldDefn("datetime", ogr.OFTDateTime)
+        lyr.CreateField(field)
+
+        f = ogr.Feature(lyr.GetLayerDefn())
+        f.SetGeometry(ogr.CreateGeometryFromWkt("POINT (1 2)"))
+        lyr.CreateFeature(f)
+
+        f = ogr.Feature(lyr.GetLayerDefn())
+        f.SetField("datetime", "2022-05-31T12:34:56.789Z")
+        f.SetGeometry(ogr.CreateGeometryFromWkt("POINT (1 2)"))
+        lyr.CreateFeature(f)
+
+        f = ogr.Feature(lyr.GetLayerDefn())
+        f.SetField("datetime", "2022-05-31T12:34:56")
+        f.SetGeometry(ogr.CreateGeometryFromWkt("POINT (1 2)"))
+        lyr.CreateFeature(f)
+
+        f = ogr.Feature(lyr.GetLayerDefn())
+        f.SetField("datetime", "2022-05-31T12:34:56+12:30")
+        f.SetGeometry(ogr.CreateGeometryFromWkt("POINT (1 2)"))
+        lyr.CreateFeature(f)
+
+    with ogr.Open(filename) as ds:
+        lyr = ds.GetLayer(0)
+        stream = lyr.GetArrowStreamAsNumPy(
+            options=["USE_MASKED_ARRAYS=NO", "DATETIME_AS_STRING=YES"]
+        )
+        batches = [batch for batch in stream]
+        assert len(batches) == 1
+        batch = batches[0]
+        assert len(batch["datetime"]) == 4
+        assert batch["datetime"][0] == b""
+        assert batch["datetime"][1] == b"2022-05-31T12:34:56.789Z"
+        assert batch["datetime"][2] == b"2022-05-31T12:34:56"
+        assert batch["datetime"][3] == b"2022-05-31T12:34:56+12:30"

autotest/ogr/ogr_gpkg.py

@@ -10766,3 +10766,76 @@ def test_gpkg_secure_delete(tmp_vsimem):
             with ds.ExecuteSQL("PRAGMA secure_delete") as sql_lyr:
                 f = sql_lyr.GetNextFeature()
                 assert f.GetField(0) == 0
+
+
+###############################################################################
+# Test DATETIME_AS_STRING=YES GetArrowStream() option
+
+
+def test_ogr_gpkg_arrow_stream_numpy_datetime_as_string(tmp_vsimem):
+    pytest.importorskip("osgeo.gdal_array")
+    pytest.importorskip("numpy")
+
+    filename = str(tmp_vsimem / "datetime_as_string.gpkg")
+    ds = ogr.GetDriverByName("GPKG").CreateDataSource(filename)
+    lyr = ds.CreateLayer("test")
+
+    field = ogr.FieldDefn("datetime", ogr.OFTDateTime)
+    lyr.CreateField(field)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    lyr.CreateFeature(f)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    f.SetField("datetime", "2022-05-31T12:34:56.789Z")
+    lyr.CreateFeature(f)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    f.SetField("datetime", "2022-05-31T12:34:56.000")
+    lyr.CreateFeature(f)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    f.SetField("datetime", "2022-05-31T12:34:56.000+12:30")
+    lyr.CreateFeature(f)
+
+    # Test DATETIME_AS_STRING=YES
+    stream = lyr.GetArrowStreamAsNumPy(
+        options=["USE_MASKED_ARRAYS=NO", "DATETIME_AS_STRING=YES"]
+    )
+    batches = [batch for batch in stream]
+    assert len(batches) == 1
+    batch = batches[0]
+    assert len(batch["datetime"]) == 4
+    assert batch["datetime"][0] == b""
+    assert batch["datetime"][1] == b"2022-05-31T12:34:56.789Z"
+    assert batch["datetime"][2] == b"2022-05-31T12:34:56.000"
+    assert batch["datetime"][3] == b"2022-05-31T12:34:56.000+12:30"
+
+    # Setting a filer tests the use of the less optimized
+    # OGRGeoPackageTableLayer::GetNextArray() implementation
+    lyr.SetAttributeFilter("1 = 1")
+    stream = lyr.GetArrowStreamAsNumPy(
+        options=["USE_MASKED_ARRAYS=NO", "DATETIME_AS_STRING=YES"]
+    )
+    lyr.SetAttributeFilter(None)
+    batches = [batch for batch in stream]
+    assert len(batches) == 1
+    batch = batches[0]
+    assert len(batch["datetime"]) == 4
+    assert batch["datetime"][0] == b""
+    assert batch["datetime"][1] == b"2022-05-31T12:34:56.789Z"
+    assert batch["datetime"][2] == b"2022-05-31T12:34:56.000"
+    assert batch["datetime"][3] == b"2022-05-31T12:34:56.000+12:30"
+
+    with ds.ExecuteSQL("SELECT * FROM test") as sql_lyr:
+        stream = sql_lyr.GetArrowStreamAsNumPy(
+            options=["USE_MASKED_ARRAYS=NO", "DATETIME_AS_STRING=YES"]
+        )
+        batches = [batch for batch in stream]
+        assert len(batches) == 1
+        batch = batches[0]
+        assert len(batch["datetime"]) == 4
+        assert batch["datetime"][0] == b""
+        assert batch["datetime"][1] == b"2022-05-31T12:34:56.789Z"
+        assert batch["datetime"][2] == b"2022-05-31T12:34:56.000"
+        assert batch["datetime"][3] == b"2022-05-31T12:34:56.000+12:30"

autotest/ogr/ogr_mem.py

@@ -979,6 +979,101 @@ def test_ogr_mem_arrow_stream_numpy():
     assert len(batches) == 0
 
 
+###############################################################################
+# Test DATETIME_AS_STRING=YES GetArrowStream() option
+
+
+def test_ogr_mem_arrow_stream_numpy_datetime_as_string():
+    pytest.importorskip("osgeo.gdal_array")
+    pytest.importorskip("numpy")
+
+    ds = ogr.GetDriverByName("Memory").CreateDataSource("")
+    lyr = ds.CreateLayer("foo")
+
+    field = ogr.FieldDefn("datetime", ogr.OFTDateTime)
+    lyr.CreateField(field)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    lyr.CreateFeature(f)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    f.SetField("datetime", "2022-05-31T12:34:56.789Z")
+    lyr.CreateFeature(f)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    f.SetField("datetime", "2022-05-31T12:34:56")
+    lyr.CreateFeature(f)
+
+    f = ogr.Feature(lyr.GetLayerDefn())
+    f.SetField("datetime", "2022-05-31T12:34:56+12:30")
+    lyr.CreateFeature(f)
+
+    # Test DATETIME_AS_STRING=YES
+    stream = lyr.GetArrowStreamAsNumPy(
+        options=["USE_MASKED_ARRAYS=NO", "DATETIME_AS_STRING=YES"]
+    )
+    batches = [batch for batch in stream]
+    assert len(batches) == 1
+    batch = batches[0]
+    assert len(batch["datetime"]) == 4
+    assert batch["datetime"][0] == b""
+    assert batch["datetime"][1] == b"2022-05-31T12:34:56.789Z"
+    assert batch["datetime"][2] == b"2022-05-31T12:34:56"
+    assert batch["datetime"][3] == b"2022-05-31T12:34:56+12:30"
+
+
+###############################################################################
+# Test CreateFieldFromArrowSchema() when there is a GDAL:OGR:type=DateTime
+# Arrow schema metadata.
+
+
+@gdaltest.enable_exceptions()
+def test_ogr_mem_arrow_write_with_datetime_as_string():
+
+    src_ds = ogr.GetDriverByName("Memory").CreateDataSource("")
+    src_lyr = src_ds.CreateLayer("src_lyr", geom_type=ogr.wkbNone)
+
+    field = ogr.FieldDefn("dt", ogr.OFTDateTime)
+    src_lyr.CreateField(field)
+
+    f = ogr.Feature(src_lyr.GetLayerDefn())
+    src_lyr.CreateFeature(f)
+
+    f = ogr.Feature(src_lyr.GetLayerDefn())
+    f.SetField("dt", "2022-05-31T12:34:56.789Z")
+    src_lyr.CreateFeature(f)
+
+    f = ogr.Feature(src_lyr.GetLayerDefn())
+    f.SetField("dt", "2022-05-31T12:34:56")
+    src_lyr.CreateFeature(f)
+
+    f = ogr.Feature(src_lyr.GetLayerDefn())
+    f.SetField("dt", "2022-05-31T12:34:56+12:30")
+    src_lyr.CreateFeature(f)
+
+    ds = ogr.GetDriverByName("Memory").CreateDataSource("")
+    dst_lyr = ds.CreateLayer("dst_lyr")
+
+    stream = src_lyr.GetArrowStream(["DATETIME_AS_STRING=YES"])
+    schema = stream.GetSchema()
+
+    for i in range(schema.GetChildrenCount()):
+        dst_lyr.CreateFieldFromArrowSchema(schema.GetChild(i))
+
+    while True:
+        array = stream.GetNextRecordBatch()
+        if array is None:
+            break
+        dst_lyr.WriteArrowBatch(schema, array)
+
+    assert [f.GetField("dt") for f in dst_lyr] == [
+        None,
+        "2022/05/31 12:34:56.789+00",
+        "2022/05/31 12:34:56",
+        "2022/05/31 12:34:56+1230",
+    ]
+
+
 ###############################################################################