Merge pull request #3330 from CurtizJ/CLICKHOUSE-4005

Interpret empty null_value in external dictionaries as type default value [ClLICKHOUSE-4005]
ClickHouse · Oct 9, 2018 · b776633 · b776633
2 parents caaa7ff + 33b4a50
commit b776633
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Showing 3 changed files with 22 additions and 6 deletions.
diff --git a/dbms/src/Dictionaries/DictionaryStructure.cpp b/dbms/src/Dictionaries/DictionaryStructure.cpp
@@ -316,10 +316,15 @@ std::vector<DictionaryAttribute> DictionaryStructure::getAttributes(
             const auto null_value_string = config.getString(prefix + "null_value");
             try
             {
-                ReadBufferFromString null_value_buffer{null_value_string};
-                auto column_with_null_value = type->createColumn();
-                type->deserializeTextEscaped(*column_with_null_value, null_value_buffer, format_settings);
-                null_value = (*column_with_null_value)[0];
+                if (null_value_string.empty())
+                    null_value = type->getDefault();
+                else
+                {
+                    ReadBufferFromString null_value_buffer{null_value_string};
+                    auto column_with_null_value = type->createColumn();
+                    type->deserializeTextEscaped(*column_with_null_value, null_value_buffer, format_settings);
+                    null_value = (*column_with_null_value)[0];
+                }
             }
             catch (Exception & e)
             {

diff --git a/dbms/tests/integration/test_dictionaries/generate_dictionaries.py b/dbms/tests/integration/test_dictionaries/generate_dictionaries.py
@@ -20,11 +20,11 @@
 ]
 
 implicit_defaults = [
-    '1', '1', '1', '1',
+    '1', '1', '1', '',
     '-1', '-1', '-1', '-1',
     '2.71828', '2.71828',
     'implicit-default',
-    '2015-11-25', '2015-11-25 00:00:00'
+    '2015-11-25', ''
 ]
 
 

diff --git a/dbms/tests/integration/test_dictionaries/test.py b/dbms/tests/integration/test_dictionaries/test.py
@@ -121,3 +121,14 @@ def test_select_all_from_cached(cached_dictionary_structure):
     diff = test_table.compare_by_keys(keys, result.lines, use_parent, add_not_found_rows=True)
     print test_table.process_diff(diff)
     assert not diff
+
+def test_null_value(started_cluster):
+    query = instance.query
+
+    assert TSV(query("select dictGetUInt8('clickhouse_cache', 'UInt8_', toUInt64(12121212))")) == TSV("1")
+    assert TSV(query("select dictGetString('clickhouse_cache', 'String_', toUInt64(12121212))")) == TSV("implicit-default")
+    assert TSV(query("select dictGetDate('clickhouse_cache', 'Date_', toUInt64(12121212))")) == TSV("2015-11-25")
+
+    # Check, that empty null_value interprets as default value
+    assert TSV(query("select dictGetUInt64('clickhouse_cache', 'UInt64_', toUInt64(12121212))")) == TSV("0")
+    assert TSV(query("select dictGetDateTime('clickhouse_cache', 'DateTime_', toUInt64(12121212))")) == TSV("0000-00-00 00:00:00")