MDEV-16804 SYSTEM VERSIONING columns not showing as GENERATED

Closes #830

mysql-test/suite/versioning/r/create.result

@@ -54,7 +54,7 @@ character_octet_length	NULL
 character_set_name	NULL
 collation_name	NULL
 column_key	
-extra	INVISIBLE
+extra	STORED GENERATED, INVISIBLE
 column_comment	start
 is_generated	ALWAYS
 generation_expression	ROW START
@@ -69,7 +69,7 @@ character_octet_length	NULL
 character_set_name	NULL
 collation_name	NULL
 column_key	
-extra	INVISIBLE
+extra	STORED GENERATED, INVISIBLE
 column_comment	end
 is_generated	ALWAYS
 generation_expression	ROW END

mysql-test/suite/versioning/r/simple.result

@@ -71,3 +71,135 @@ and d.dept_id = e.dept_id;
 emp_id	dept_id	name	salary	dept_id	name
 1	10	bill	2000	10	accounting
 drop table emp, dept;
+create table t1 (
+a timestamp(6),
+b timestamp(6) generated always as (a + interval 1 day),
+c timestamp(6) generated always as (a + interval 1 month) stored,
+d timestamp(6) generated always as row start,
+e timestamp(6) generated always as row end,
+period for system_time(d,e)
+) with system versioning;
+show columns from t1;
+Field	Type	Null	Key	Default	Extra
+a	timestamp(6)	NO		current_timestamp(6)	on update current_timestamp(6)
+b	timestamp(6)	YES		NULL	VIRTUAL GENERATED
+c	timestamp(6)	YES		NULL	STORED GENERATED
+d	timestamp(6)	NO		NULL	STORED GENERATED
+e	timestamp(6)	NO		NULL	STORED GENERATED
+select *,'---' from information_schema.columns where table_name='t1';
+TABLE_CATALOG	def
+TABLE_SCHEMA	test
+TABLE_NAME	t1
+COLUMN_NAME	a
+ORDINAL_POSITION	1
+COLUMN_DEFAULT	current_timestamp(6)
+IS_NULLABLE	NO
+DATA_TYPE	timestamp
+CHARACTER_MAXIMUM_LENGTH	NULL
+CHARACTER_OCTET_LENGTH	NULL
+NUMERIC_PRECISION	NULL
+NUMERIC_SCALE	NULL
+DATETIME_PRECISION	6
+CHARACTER_SET_NAME	NULL
+COLLATION_NAME	NULL
+COLUMN_TYPE	timestamp(6)
+COLUMN_KEY	
+EXTRA	on update current_timestamp(6)
+PRIVILEGES	select,insert,update,references
+COLUMN_COMMENT	
+IS_GENERATED	NEVER
+GENERATION_EXPRESSION	NULL
+---	---
+TABLE_CATALOG	def
+TABLE_SCHEMA	test
+TABLE_NAME	t1
+COLUMN_NAME	b
+ORDINAL_POSITION	2
+COLUMN_DEFAULT	NULL
+IS_NULLABLE	YES
+DATA_TYPE	timestamp
+CHARACTER_MAXIMUM_LENGTH	NULL
+CHARACTER_OCTET_LENGTH	NULL
+NUMERIC_PRECISION	NULL
+NUMERIC_SCALE	NULL
+DATETIME_PRECISION	6
+CHARACTER_SET_NAME	NULL
+COLLATION_NAME	NULL
+COLUMN_TYPE	timestamp(6)
+COLUMN_KEY	
+EXTRA	VIRTUAL GENERATED
+PRIVILEGES	select,insert,update,references
+COLUMN_COMMENT	
+IS_GENERATED	ALWAYS
+GENERATION_EXPRESSION	`a` + interval 1 day
+---	---
+TABLE_CATALOG	def
+TABLE_SCHEMA	test
+TABLE_NAME	t1
+COLUMN_NAME	c
+ORDINAL_POSITION	3
+COLUMN_DEFAULT	NULL
+IS_NULLABLE	YES
+DATA_TYPE	timestamp
+CHARACTER_MAXIMUM_LENGTH	NULL
+CHARACTER_OCTET_LENGTH	NULL
+NUMERIC_PRECISION	NULL
+NUMERIC_SCALE	NULL
+DATETIME_PRECISION	6
+CHARACTER_SET_NAME	NULL
+COLLATION_NAME	NULL
+COLUMN_TYPE	timestamp(6)
+COLUMN_KEY	
+EXTRA	STORED GENERATED
+PRIVILEGES	select,insert,update,references
+COLUMN_COMMENT	
+IS_GENERATED	ALWAYS
+GENERATION_EXPRESSION	`a` + interval 1 month
+---	---
+TABLE_CATALOG	def
+TABLE_SCHEMA	test
+TABLE_NAME	t1
+COLUMN_NAME	d
+ORDINAL_POSITION	4
+COLUMN_DEFAULT	NULL
+IS_NULLABLE	NO
+DATA_TYPE	timestamp
+CHARACTER_MAXIMUM_LENGTH	NULL
+CHARACTER_OCTET_LENGTH	NULL
+NUMERIC_PRECISION	NULL
+NUMERIC_SCALE	NULL
+DATETIME_PRECISION	6
+CHARACTER_SET_NAME	NULL
+COLLATION_NAME	NULL
+COLUMN_TYPE	timestamp(6)
+COLUMN_KEY	
+EXTRA	STORED GENERATED
+PRIVILEGES	select,insert,update,references
+COLUMN_COMMENT	
+IS_GENERATED	ALWAYS
+GENERATION_EXPRESSION	ROW START
+---	---
+TABLE_CATALOG	def
+TABLE_SCHEMA	test
+TABLE_NAME	t1
+COLUMN_NAME	e
+ORDINAL_POSITION	5
+COLUMN_DEFAULT	NULL
+IS_NULLABLE	NO
+DATA_TYPE	timestamp
+CHARACTER_MAXIMUM_LENGTH	NULL
+CHARACTER_OCTET_LENGTH	NULL
+NUMERIC_PRECISION	NULL
+NUMERIC_SCALE	NULL
+DATETIME_PRECISION	6
+CHARACTER_SET_NAME	NULL
+COLLATION_NAME	NULL
+COLUMN_TYPE	timestamp(6)
+COLUMN_KEY	
+EXTRA	STORED GENERATED
+PRIVILEGES	select,insert,update,references
+COLUMN_COMMENT	
+IS_GENERATED	ALWAYS
+GENERATION_EXPRESSION	ROW END
+---	---
+drop table t1;

mysql-test/suite/versioning/t/simple.test

@@ -71,3 +71,19 @@ where d.dept_id = 10
   and d.dept_id = e.dept_id;
 
 drop table emp, dept;
+
+#
+# MDEV-16804 SYSTEM VERSIONING columns not showing as GENERATED
+#
+create table t1 (
+  a timestamp(6),
+  b timestamp(6) generated always as (a + interval 1 day),
+  c timestamp(6) generated always as (a + interval 1 month) stored,
+  d timestamp(6) generated always as row start,
+  e timestamp(6) generated always as row end,
+  period for system_time(d,e)
+) with system versioning;
+show columns from t1;
+query_vertical select *,'---' from information_schema.columns where table_name='t1';
+drop table t1;
+

sql/sql_show.cc

@@ -6001,9 +6001,15 @@ static int get_schema_column_record(THD *thd, TABLE_LIST *tables,
     else if (field->flags & VERS_SYSTEM_FIELD)
     {
       if (field->flags & VERS_SYS_START_FLAG)
+      {
         table->field[21]->store(STRING_WITH_LEN("ROW START"), cs);
+        buf.set(STRING_WITH_LEN("STORED GENERATED"), cs);
+      }
       else
+      {
         table->field[21]->store(STRING_WITH_LEN("ROW END"), cs);
+        buf.set(STRING_WITH_LEN("STORED GENERATED"), cs);
+      }
       table->field[21]->set_notnull();
       table->field[20]->store(STRING_WITH_LEN("ALWAYS"), cs);
     }