MDEV-14798 Add, drop system versioning semantic and syntax

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

@@ -125,7 +125,10 @@ with system versioning;
 select * from t for system_time all;
 a
 alter table t drop column row_start;
+ERROR HY000: Wrong parameters for `t`: missing 'DROP COLUMN row_end'
 alter table t drop column row_end;
+ERROR HY000: Wrong parameters for `t`: missing 'DROP COLUMN row_start'
+alter table t drop column row_start, drop column row_end;
 select * from t for system_time all;
 a
 alter table t drop column row_start;
@@ -383,30 +386,6 @@ ERROR HY000: Can not change system versioning field `row_start`
 insert into t values (1);
 alter table t modify column row_start bigint unsigned;
 ERROR HY000: Can not change system versioning field `row_start`
-create or replace table t (
-a int,
-row_start timestamp(6) as row start invisible,
-row_end timestamp(6) as row end invisible,
-period for system_time(row_start, row_end)
-) with system versioning;
-select * from t;
-a
-alter table t drop system versioning;
-ERROR HY000: System versioning field `row_start` exists
-alter table t drop column row_start;
-select * from t;
-a
-alter table t drop system versioning;
-ERROR HY000: System versioning field `row_end` exists
-alter table t drop column row_end;
-select * from t;
-a
-alter table t drop system versioning;
-show create table t;
-Table	Create Table
-t	CREATE TABLE `t` (
-  `a` int(11) DEFAULT NULL
-) ENGINE=MyISAM DEFAULT CHARSET=latin1
 set system_versioning_alter_history= SURVIVE;
 ERROR 42000: Variable 'system_versioning_alter_history' can't be set to the value of 'SURVIVE'
 set system_versioning_alter_history= DROP;
@@ -465,5 +444,9 @@ ERROR 42S21: Duplicate column name 'row_start'
 set statement system_versioning_alter_history=keep for
 alter table t1 add column row_start timestamp(6);
 ERROR 42S21: Duplicate column name 'row_start'
+# MDEV-14798 Add, drop system versioning semantic and syntax
+create or replace table t (a int) with system versioning;
+alter table t add period for system_time(sys_trx_start, sys_trx_end);
+ERROR HY000: Table `t` is already system-versioned
 drop database test;
 create database test;

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

@@ -78,8 +78,11 @@ create or replace table t (
 with system versioning;
 
 select * from t for system_time all;
+--error ER_MISSING
 alter table t drop column row_start;
+--error ER_MISSING
 alter table t drop column row_end;
+alter table t drop column row_start, drop column row_end;
 select * from t for system_time all;
 
 --error ER_CANT_DROP_FIELD_OR_KEY
@@ -263,28 +266,6 @@ insert into t values (1);
 --error ER_VERS_ALTER_SYSTEM_FIELD
 alter table t modify column row_start bigint unsigned;
 
-create or replace table t (
-  a int,
-  row_start timestamp(6) as row start invisible,
-  row_end timestamp(6) as row end invisible,
-  period for system_time(row_start, row_end)
-) with system versioning;
-select * from t;
-
---error ER_VERS_SYS_FIELD_EXISTS
-alter table t drop system versioning;
-alter table t drop column row_start;
-select * from t;
-
---error ER_VERS_SYS_FIELD_EXISTS
-alter table t drop system versioning;
-alter table t drop column row_end;
-select * from t;
-
-alter table t drop system versioning;
-show create table t;
-
-
 ## These experimental options are now disabled
 
 --error ER_WRONG_VALUE_FOR_VAR
@@ -404,5 +385,11 @@ alter table t1 add column row_start int;
 set statement system_versioning_alter_history=keep for
 alter table t1 add column row_start timestamp(6);
 
+--echo # MDEV-14798 Add, drop system versioning semantic and syntax
+create or replace table t (a int) with system versioning;
+
+--error ER_VERS_ALREADY_VERSIONED
+alter table t add period for system_time(sys_trx_start, sys_trx_end);
+
 drop database test;
 create database test;

sql/handler.cc

@@ -7133,11 +7133,17 @@ bool Table_scope_and_contents_source_st::vers_fix_system_fields(
   return false;
 }
 
-static bool add_field_to_drop_list(THD *thd, Alter_info *alter_info,
-                                   Field *field)
+static bool add_field_to_drop_list_if_not_exists(THD *thd, Alter_info *alter_info, Field *field)
 {
   DBUG_ASSERT(field);
   DBUG_ASSERT(field->field_name.str);
+  List_iterator_fast<Alter_drop> it(alter_info->drop_list);
+  while (Alter_drop *drop= it++)
+  {
+    if (!my_strcasecmp(system_charset_info, field->field_name.str, drop->name))
+      return false;
+  }
+
   alter_info->flags|= Alter_info::ALTER_DROP_COLUMN;
   Alter_drop *ad= new (thd->mem_root)
       Alter_drop(Alter_drop::COLUMN, field->field_name.str, false);
@@ -7201,21 +7207,8 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
       return true;
     }
 
-    if (share->vers_start_field()->invisible < INVISIBLE_SYSTEM)
-    {
-      my_error(ER_VERS_SYS_FIELD_EXISTS, MYF(0),
-               share->vers_start_field()->field_name.str);
-      return true;
-    }
-    if (share->vers_end_field()->invisible < INVISIBLE_SYSTEM)
-    {
-      my_error(ER_VERS_SYS_FIELD_EXISTS, MYF(0),
-               share->vers_end_field()->field_name.str);
-      return true;
-    }
-
-    if (add_field_to_drop_list(thd, alter_info, share->vers_start_field()) ||
-        add_field_to_drop_list(thd, alter_info, share->vers_end_field()))
+    if (add_field_to_drop_list_if_not_exists(thd, alter_info, share->vers_start_field()) ||
+        add_field_to_drop_list_if_not_exists(thd, alter_info, share->vers_end_field()))
       return true;
 
     if (share->primary_key != MAX_KEY && !is_adding_primary_key(alter_info) &&
@@ -7275,6 +7268,15 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
     return true;
   }
 
+  if (add_period)
+  {
+    if (share->versioned)
+    {
+      my_error(ER_VERS_ALREADY_VERSIONED, MYF(0), table_name);
+      return true;
+    }
+  }
+
   if (share->versioned)
   {
     // copy info from existing table
@@ -7346,6 +7348,16 @@ bool Vers_parse_info::fix_alter_info(THD *thd, Alter_info *alter_info,
         if (done_start && done_end)
           break;
       }
+
+      if ((done_start || done_end) && done_start != done_end)
+      {
+        String tmp;
+        tmp.append("DROP COLUMN ");
+        tmp.append(done_start ? table->vers_end_field()->field_name
+                              : table->vers_start_field()->field_name);
+        my_error(ER_MISSING, MYF(0), table_name, tmp.c_ptr());
+        return true;
+      }
     }
 
     return false;
@@ -7426,7 +7438,7 @@ Vers_parse_info::fix_create_like(Alter_info &alter_info, HA_CREATE_INFO &create_
 
 bool Vers_parse_info::need_check(const Alter_info *alter_info) const
 {
-  return versioned_fields || unversioned_fields ||
+  return versioned_fields || unversioned_fields || add_period ||
          alter_info->flags & Alter_info::ALTER_ADD_SYSTEM_VERSIONING ||
          alter_info->flags & Alter_info::ALTER_DROP_SYSTEM_VERSIONING || *this;
 }

sql/handler.h

@@ -1725,7 +1725,8 @@ struct Vers_parse_info
 {
   Vers_parse_info() :
     versioned_fields(false),
-    unversioned_fields(false)
+    unversioned_fields(false),
+    add_period(false)
   {}
 
   struct start_end_t
@@ -1789,6 +1790,7 @@ struct Vers_parse_info
   */
   bool versioned_fields : 1;
   bool unversioned_fields : 1;
+  bool add_period : 1;  // ADD PERIOD FOR SYSTEM_TIME was specified
 };
 
 /**

sql/sql_yacc.yy

@@ -8080,6 +8080,7 @@ alter_list_item:
           }
         | ADD period_for_system_time
           {
+            Lex->vers_get_info().add_period= true;
           }
         | add_column '(' create_field_list ')'
           {