SQL: recursive CTE inner derived vers_conditions [fix #385]

Author: midenok

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

@@ -91,6 +91,23 @@ insert addr values (1, 'Moscow'), (2, 'New York'), (3, 'London');
 set @ts=now(6);
 delete from emp;
 delete from addr;
+with recursive
+ancestors
+as
+(
+select e.emp_id, e.name, e.mgr
+from emp for system_time as of timestamp @ts as e
+where name = 'bill'
+  union
+select ee.emp_id, ee.name, ee.mgr
+from emp for system_time as of timestamp @ts as ee, ancestors as a
+where ee.mgr = a.emp_id
+)
+select * from ancestors;
+emp_id	name	mgr
+1	bill	0
+2	bill	1
+3	kate	1
 insert emp values (4, 'john', 1);
 insert addr values (4, 'Paris');
 with ancestors as (select * from emp natural join addr) select * from ancestors;

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

@@ -90,6 +90,21 @@ insert addr values (1, 'Moscow'), (2, 'New York'), (3, 'London');
 set @ts=now(6);
 delete from emp;
 delete from addr;
+
+with recursive
+ancestors
+as
+(
+  select e.emp_id, e.name, e.mgr
+  from emp for system_time as of timestamp @ts as e
+  where name = 'bill'
+  union
+  select ee.emp_id, ee.name, ee.mgr
+  from emp for system_time as of timestamp @ts as ee, ancestors as a
+  where ee.mgr = a.emp_id
+)
+select * from ancestors;
+
 insert emp values (4, 'john', 1);
 insert addr values (4, 'Paris');
 with ancestors as (select * from emp natural join addr) select * from ancestors;

sql/sql_derived.cc

@@ -850,8 +850,6 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
         {
           sl->vers_export_outer= impli_table->vers_conditions;
         }
-        else
-          sl->vers_import_outer= true; // FIXME: is needed?
       }
     } // if (sl->table_list.elements > 0)
     // System Versioning end

sql/sql_lex.cc

@@ -2313,7 +2313,6 @@ void st_select_lex::init_select()
   in_tvc= false;
   vers_saved_where= NULL;
   vers_export_outer.empty();
-  vers_import_outer= false;
   versioned_tables= 0;
 }
 

sql/sql_lex.h

@@ -1049,7 +1049,6 @@ class st_select_lex: public st_select_lex_node
   Item *vers_saved_where;
 public:
   vers_select_conds_t vers_export_outer;
-  bool vers_import_outer;
   uint versioned_tables;
   int vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr);
   /* push new Item_field into item_list */

sql/sql_select.cc

@@ -829,19 +829,27 @@ int SELECT_LEX::vers_setup_conds(THD *thd, TABLE_LIST *tables, COND **where_expr
     vers_select_conds_t &vers_conditions= table->vers_conditions;
 
     // propagate system_time from nearest outer SELECT_LEX
-    if (!vers_conditions && outer_slex && vers_import_outer)
+    if (!vers_conditions && outer_slex)
     {
       TABLE_LIST* derived= master_unit()->derived;
-      // inner SELECT may not be a derived table (derived == NULL)
-      while (derived && outer_slex && (!derived->vers_conditions || derived->vers_conditions.from_inner))
+      if (derived == table && vers_export_outer) // recursive CTE
       {
-        derived= outer_slex->master_unit()->derived;
-        outer_slex= outer_slex->next_select_in_list();
+        vers_conditions= vers_export_outer;
       }
-      if (derived && outer_slex && !derived->vers_conditions.from_inner)
+      else
       {
-        DBUG_ASSERT(derived->vers_conditions);
-        vers_conditions= derived->vers_conditions;
+        // inner SELECT may not be a derived table (derived == NULL)
+        while (derived && outer_slex &&
+          (!derived->vers_conditions || derived->vers_conditions.from_inner))
+        {
+          derived= outer_slex->master_unit()->derived;
+          outer_slex= outer_slex->next_select_in_list();
+        }
+        if (derived && outer_slex && !derived->vers_conditions.from_inner)
+        {
+          DBUG_ASSERT(derived->vers_conditions);
+          vers_conditions= derived->vers_conditions;
+        }
       }
     }