Fixed bug when fetching a timestamp with nanosecond precision into a

data frame (#538).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -19,6 +19,9 @@ oracledb `3.4.1 <https://github.com/oracle/python-oracledb/compare/v3.4.0...v3.4
 Thin Mode Changes
 +++++++++++++++++
 
+#)  Fixed bug when fetching a timestamp with nanosecond precision into a data
+    frame
+    (`issue 538 <https://github.com/oracle/python-oracledb/issues/538>`__).
 #)  Fixed bug when adding a call to a PL/SQL function which returns LOBs to a
     :ref:`pipeline <pipelining>`.
 #)  Fixed bug when using bind variables with scrollable cursors.

src/oracledb/impl/base/converters.pyx

@@ -186,10 +186,19 @@ cdef int convert_date_to_arrow_timestamp(ArrowArrayImpl array_impl,
     cdef:
         cydatetime.timedelta td
         cydatetime.datetime dt
-        int64_t ts
+        int64_t ts, us
     dt = convert_date_to_python(buffer)
     td = dt - EPOCH_DATE
-    ts = int(cydatetime.total_seconds(td) * array_impl.schema_impl.time_factor)
+    ts = (<int64_t> cydatetime.timedelta_days(td)) * (24 * 60 * 60) + \
+            cydatetime.timedelta_seconds(td)
+    ts *= array_impl.schema_impl.time_factor
+    us = cydatetime.timedelta_microseconds(td)
+    if array_impl.schema_impl.time_factor == 1_000:
+        ts += us // 1_000
+    elif array_impl.schema_impl.time_factor == 1_000_000:
+        ts += us
+    elif array_impl.schema_impl.time_factor != 1:
+        ts += us * 1_000
     array_impl.append_int(ts)
 
 

tests/test_9300_dataframe_requested_schema.py

@@ -28,6 +28,7 @@
 
 import datetime
 
+import oracledb
 import pyarrow
 import pytest
 
@@ -281,28 +282,34 @@ def test_9310(dtype, value_is_date, conn):
 
 
 @pytest.mark.parametrize(
-    "dtype,value_is_date",
+    "dtype",
     [
-        (pyarrow.date32(), True),
-        (pyarrow.date64(), True),
-        (pyarrow.timestamp("s"), False),
-        (pyarrow.timestamp("us"), False),
-        (pyarrow.timestamp("ms"), False),
-        (pyarrow.timestamp("ns"), False),
+        pyarrow.date32(),
+        pyarrow.date64(),
+        pyarrow.timestamp("s"),
+        pyarrow.timestamp("us"),
+        pyarrow.timestamp("ms"),
+        pyarrow.timestamp("ns"),
     ],
 )
-def test_9311(dtype, value_is_date, conn):
+def test_9311(dtype, conn):
     "9311 - fetch_df_all() for TIMESTAMP"
     requested_schema = pyarrow.schema([("TIMESTAMP_COL", dtype)])
-    value = datetime.datetime(2025, 1, 15)
-    statement = "select cast(:1 as timestamp) from dual"
+    value = datetime.datetime(1974, 4, 4, 0, 57, 54, 15079)
+    var = conn.cursor().var(oracledb.DB_TYPE_TIMESTAMP)
+    var.setvalue(0, value)
+    statement = "select :1 from dual"
     ora_df = conn.fetch_df_all(
-        statement, [value], requested_schema=requested_schema
+        statement, [var], requested_schema=requested_schema
     )
     tab = pyarrow.table(ora_df)
     assert tab.field("TIMESTAMP_COL").type == dtype
-    if value_is_date:
+    if not isinstance(dtype, pyarrow.TimestampType):
         value = value.date()
+    elif dtype.unit == "s":
+        value = value.replace(microsecond=0)
+    elif dtype.unit == "ms":
+        value = value.replace(microsecond=(value.microsecond // 1000) * 1000)
     assert tab["TIMESTAMP_COL"][0].as_py() == value
 
 

tests/test_9400_dataframe_requested_schema_async.py

@@ -28,6 +28,7 @@
 
 import datetime
 
+import oracledb
 import pyarrow
 import pytest
 
@@ -298,28 +299,34 @@ async def test_9410(dtype, value_is_date, async_conn):
 
 
 @pytest.mark.parametrize(
-    "dtype,value_is_date",
+    "dtype",
     [
-        (pyarrow.date32(), True),
-        (pyarrow.date64(), True),
-        (pyarrow.timestamp("s"), False),
-        (pyarrow.timestamp("us"), False),
-        (pyarrow.timestamp("ms"), False),
-        (pyarrow.timestamp("ns"), False),
+        pyarrow.date32(),
+        pyarrow.date64(),
+        pyarrow.timestamp("s"),
+        pyarrow.timestamp("us"),
+        pyarrow.timestamp("ms"),
+        pyarrow.timestamp("ns"),
     ],
 )
-async def test_9411(dtype, value_is_date, async_conn):
+async def test_9411(dtype, async_conn):
     "9411 - fetch_df_all() for TIMESTAMP"
     requested_schema = pyarrow.schema([("TIMESTAMP_COL", dtype)])
-    value = datetime.datetime(2025, 1, 15)
-    statement = "select cast(:1 as timestamp) from dual"
+    value = datetime.datetime(1974, 4, 4, 0, 57, 54, 15079)
+    var = async_conn.cursor().var(oracledb.DB_TYPE_TIMESTAMP)
+    var.setvalue(0, value)
+    statement = "select :1 from dual"
     ora_df = await async_conn.fetch_df_all(
-        statement, [value], requested_schema=requested_schema
+        statement, [var], requested_schema=requested_schema
     )
     tab = pyarrow.table(ora_df)
     assert tab.field("TIMESTAMP_COL").type == dtype
-    if value_is_date:
+    if not isinstance(dtype, pyarrow.TimestampType):
         value = value.date()
+    elif dtype.unit == "s":
+        value = value.replace(microsecond=0)
+    elif dtype.unit == "ms":
+        value = value.replace(microsecond=(value.microsecond // 1000) * 1000)
     assert tab["TIMESTAMP_COL"][0].as_py() == value