Merge pull request #55060 from vitlibar/fix-detecting-column-default-for-dist-table

Fix detecting DEFAULT for columns of a Distributed table created without AS

src/Databases/DatabasesCommon.cpp

@@ -149,6 +149,12 @@ ASTPtr getCreateQueryFromStorage(const StoragePtr & storage, const ASTPtr & ast_
                         return nullptr;
                 }
                 ast_column_declaration->type = ast_type;
+
+                if (auto column_default = metadata_ptr->columns.getDefault(column_name_and_type.name))
+                {
+                    ast_column_declaration->default_specifier = toString(column_default->kind);
+                    ast_column_declaration->default_expression = column_default->expression;
+                }
             }
             ast_expression_list->children.emplace_back(ast_column_declaration);
         }

tests/queries/0_stateless/02117_show_create_table_system.reference

@@ -51,7 +51,7 @@ CREATE TABLE system.clusters
     `database_shard_name` String,
     `database_replica_name` String,
     `is_active` Nullable(UInt8),
-    `name` String
+    `name` String ALIAS cluster
 )
 ENGINE = SystemClusters
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -134,7 +134,7 @@ CREATE TABLE system.databases
     `uuid` UUID,
     `engine_full` String,
     `comment` String,
-    `database` String
+    `database` String ALIAS name
 )
 ENGINE = SystemDatabases
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -265,7 +265,7 @@ CREATE TABLE system.events
     `event` String,
     `value` UInt64,
     `description` String,
-    `name` String
+    `name` String ALIAS event
 )
 ENGINE = SystemEvents
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -376,7 +376,7 @@ CREATE TABLE system.metrics
     `metric` String,
     `value` Int64,
     `description` String,
-    `name` String
+    `name` String ALIAS metric
 )
 ENGINE = SystemMetrics
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -513,9 +513,9 @@ CREATE TABLE system.parts
     `has_lightweight_delete` UInt8,
     `last_removal_attempt_time` DateTime,
     `removal_state` String,
-    `bytes` UInt64,
+    `bytes` UInt64 ALIAS bytes_on_disk,
-    `marks_size` UInt64,
+    `marks_size` UInt64 ALIAS marks_bytes,
-    `part_name` String
+    `part_name` String ALIAS name
 )
 ENGINE = SystemParts
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -569,9 +569,9 @@ CREATE TABLE system.parts_columns
     `subcolumns.data_compressed_bytes` Array(UInt64),
     `subcolumns.data_uncompressed_bytes` Array(UInt64),
     `subcolumns.marks_bytes` Array(UInt64),
-    `bytes` UInt64,
+    `bytes` UInt64 ALIAS bytes_on_disk,
-    `marks_size` UInt64,
+    `marks_size` UInt64 ALIAS marks_bytes,
-    `part_name` String
+    `part_name` String ALIAS name
 )
 ENGINE = SystemPartsColumns
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -616,10 +616,10 @@ CREATE TABLE system.processes
     `ProfileEvents` Map(String, UInt64),
     `Settings` Map(String, String),
     `current_database` String,
-    `ProfileEvents.Names` Array(String),
+    `ProfileEvents.Names` Array(String) ALIAS mapKeys(ProfileEvents),
-    `ProfileEvents.Values` Array(UInt64),
+    `ProfileEvents.Values` Array(UInt64) ALIAS mapValues(ProfileEvents),
-    `Settings.Names` Array(String),
+    `Settings.Names` Array(String) ALIAS mapKeys(Settings),
-    `Settings.Values` Array(String)
+    `Settings.Values` Array(String) ALIAS mapValues(Settings)
 )
 ENGINE = SystemProcesses
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -682,9 +682,9 @@ CREATE TABLE system.projection_parts
     `rows_where_ttl_info.expression` Array(String),
     `rows_where_ttl_info.min` Array(DateTime),
     `rows_where_ttl_info.max` Array(DateTime),
-    `bytes` UInt64,
+    `bytes` UInt64 ALIAS bytes_on_disk,
-    `marks_size` UInt64,
+    `marks_size` UInt64 ALIAS marks_bytes,
-    `part_name` String
+    `part_name` String ALIAS name
 )
 ENGINE = SystemProjectionParts
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -738,9 +738,9 @@ CREATE TABLE system.projection_parts_columns
     `column_data_uncompressed_bytes` UInt64,
     `column_marks_bytes` UInt64,
     `column_modification_time` Nullable(DateTime),
-    `bytes` UInt64,
+    `bytes` UInt64 ALIAS bytes_on_disk,
-    `marks_size` UInt64,
+    `marks_size` UInt64 ALIAS marks_bytes,
-    `part_name` String
+    `part_name` String ALIAS name
 )
 ENGINE = SystemProjectionPartsColumns
 COMMENT 'SYSTEM TABLE is built on the fly.'
@@ -1094,7 +1094,7 @@ CREATE TABLE system.tables
     `loading_dependencies_table` Array(String),
     `loading_dependent_database` Array(String),
     `loading_dependent_table` Array(String),
-    `table` String
+    `table` String ALIAS name
 )
 ENGINE = SystemTables
 COMMENT 'SYSTEM TABLE is built on the fly.'

tests/queries/0_stateless/02885_create_distributed_table_without_as.reference

@@ -0,0 +1,5 @@
+CREATE TABLE default.dist_tbl\n(\n    `key` UInt32,\n    `value` UInt32 DEFAULT 42\n)\nENGINE = Distributed(\'test_shard_localhost\', \'default\', \'local_tbl\', rand())
+local_tbl
+99	42
+dist_tbl
+99	42

tests/queries/0_stateless/02885_create_distributed_table_without_as.sql

@@ -0,0 +1,16 @@
+-- Here a Distributed table without AS must detect its structure.
+
+DROP TABLE IF EXISTS dist_tbl;
+DROP TABLE IF EXISTS local_tbl;
+
+CREATE TABLE local_tbl (`key` UInt32, `value` UInt32 DEFAULT 42) ENGINE = MergeTree ORDER BY key;
+CREATE TABLE dist_tbl ENGINE = Distributed('test_shard_localhost', currentDatabase(), 'local_tbl', rand());
+SHOW CREATE TABLE dist_tbl;
+INSERT INTO dist_tbl (key) SETTINGS insert_distributed_sync=1 VALUES (99);
+SELECT 'local_tbl';
+SELECT * FROM local_tbl;
+SELECT 'dist_tbl';
+SELECT * FROM dist_tbl;
+
+DROP TABLE dist_tbl;
+DROP TABLE local_tbl;