Release 0 6 14 (#246)

* Fix FixedString padding of empty string

* Remove bad 3.7 import

* Update changelog

CHANGELOG.md

@@ -14,6 +14,12 @@ In any case, this should not affect the basic usage of Superset with ClickHouse.
 your Superset installation, the ClickHouse datasource will be available with either the enhanced connection dialog
 or a standard SqlAlchemy DSN in the form of `clickhousedb://{username}:{password}@{host}:{port}`.
 
+## 0.6.14, TBD
+### Bug Fixes
+- Fixed insert error when inserting a zero length string into a FixedString column.  Closes https://github.com/ClickHouse/clickhouse-connect/issues/244
+- Removed unnecessary validate_entrypoints import from top level package __init__ that was breaking Python 3.7.  Note that Python 3.7 is EOL
+and will no longer be supported as of January 1, 2024.
+
 ## 0.6.13, 2023-09-20
 ### Bug Fix
 - Fixed an issue with the automatic retry of "connection reset errors".  This should prevent exceptions when the
@@ -32,7 +38,7 @@ to [Ashton Hudson](https://github.com/CaptainCuddleCube) for the report and the
 ### Bug fixes
 - Inserts using Pandas 2.1 would fail due to a removed method in the Pandas library.  There is now a workaround/fix for
 this.  Closes https://github.com/ClickHouse/clickhouse-connect/issues/234
-- Inserts into a FixedString column that were not the expected size could cause corrupt insert blocksd and mysterious errors
+- Inserts into a FixedString column that were not the expected size could cause corrupt insert blocks and mysterious errors
 from the ClickHouse server.  Validation has been added so that more meaningful error messages are generated if a fixed string
 value is an invalid size.  A reminder that strings which are "too short" for a FixedString column will be padded with 0 bytes, while
 strings that are "too long" will generate an exception during the insert.

clickhouse_connect/__init__.py

@@ -1,12 +1,8 @@
 from clickhouse_connect.driver import create_client
-from clickhouse_connect.entry_points import validate_entrypoints
+
 
 driver_name = 'clickhousedb'
 
 
 def get_client(**kwargs):
     return create_client(**kwargs)
-
-
-def check_ep():
-    assert validate_entrypoints() == 0

clickhouse_connect/__version__.py

@@ -1 +1 @@
-version = '0.6.13'
+version = '0.6.14'

clickhouse_connect/datatypes/string.py

@@ -101,8 +101,7 @@ def _write_column_binary(self, column: Union[Sequence, MutableSequence], dest: b
                         if len(b) > sz:
                             raise DataError(f'UTF-8 encoded FixedString value {b.hex(" ")} exceeds column size {sz}')
                         ext(b)
-                        if len(b) < sz:
-                            ext(empty[:-len(b)])
+                        ext(empty[:sz - len(b)])
             else:
                 for x in column:
                     try:
@@ -112,8 +111,7 @@ def _write_column_binary(self, column: Union[Sequence, MutableSequence], dest: b
                     if len(b) > sz:
                         raise DataError(f'UTF-8 encoded FixedString value {b.hex(" ")} exceeds column size {sz}')
                     ext(b)
-                    if len(b) < sz:
-                        ext(empty[:-len(b)])
+                    ext(empty[:sz - len(b)])
         elif self.nullable:
             for b in column:
                 if not b:

examples/write_perf.py

@@ -1,8 +1,9 @@
 #!/usr/bin/env python -u
 
+# pylint: disable=import-error
 import time
 import random
-import clickhouse_driver  # pylint: disable=import-error
+import clickhouse_driver
 
 import clickhouse_connect
 from clickhouse_connect.tools.testing import TableContext

tests/integration_tests/test_native.py

@@ -187,3 +187,13 @@ def test_decimal_rounding(test_client: Client, table_context: Callable):
 def test_empty_maps(test_client: Client):
     result = test_client.query("select Cast(([],[]), 'Map(String, Map(String, String))')")
     assert result.first_row[0] == {}
+
+
+def test_fixed_str_padding(test_client: Client, table_context: Callable):
+    table = 'test_fixed_str_padding'
+    with table_context(table, 'key Int32, value FixedString(3)'):
+        test_client.insert(table, [[1, 'abc']])
+        test_client.insert(table, [[2, 'a']])
+        test_client.insert(table, [[3, '']])
+        result = test_client.query(f'select * from {table} ORDER BY key')
+        assert result.result_columns[1] == [b'abc', b'a\x00\x00', b'\x00\x00\x00']