mdev-9864: cleanup, re-factoring.

Added comments.
Added reaction for exceeding maximum number of elements in with clause.
Added a test case to check this reaction.
Added a test case where the specification of a recursive table
uses two non-recursive with tables.

mysql-test/r/cte_nonrecursive.result

@@ -797,6 +797,9 @@ select t1.b from t2,t1 where t1.a = t2.c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	4	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	Using where; Using join buffer (flat, BNL join)
+# too many with elements in with clause
+with s65 as (select * from t1), s64 as (select * from t1) , s63 as (select * from t1) , s62 as (select * from t1) , s61 as (select * from t1) , s60 as (select * from t1) , s59 as (select * from t1) , s58 as (select * from t1) , s57 as (select * from t1) , s56 as (select * from t1) , s55 as (select * from t1) , s54 as (select * from t1) , s53 as (select * from t1) , s52 as (select * from t1) , s51 as (select * from t1) , s50 as (select * from t1) , s49 as (select * from t1) , s48 as (select * from t1) , s47 as (select * from t1) , s46 as (select * from t1) , s45 as (select * from t1) , s44 as (select * from t1) , s43 as (select * from t1) , s42 as (select * from t1) , s41 as (select * from t1) , s40 as (select * from t1) , s39 as (select * from t1) , s38 as (select * from t1) , s37 as (select * from t1) , s36 as (select * from t1) , s35 as (select * from t1) , s34 as (select * from t1) , s33 as (select * from t1) , s32 as (select * from t1) , s31 as (select * from t1) , s30 as (select * from t1) , s29 as (select * from t1) , s28 as (select * from t1) , s27 as (select * from t1) , s26 as (select * from t1) , s25 as (select * from t1) , s24 as (select * from t1) , s23 as (select * from t1) , s22 as (select * from t1) , s21 as (select * from t1) , s20 as (select * from t1) , s19 as (select * from t1) , s18 as (select * from t1) , s17 as (select * from t1) , s16 as (select * from t1) , s15 as (select * from t1) , s14 as (select * from t1) , s13 as (select * from t1) , s12 as (select * from t1) , s11 as (select * from t1) , s10 as (select * from t1) , s9 as (select * from t1) , s8 as (select * from t1) , s7 as (select * from t1) , s6 as (select * from t1) , s5 as (select * from t1) , s4 as (select * from t1) , s3 as (select * from t1) , s2 as (select * from t1) , s1 as (select * from t1)  select * from s65;
+ERROR HY000: Too many WITH elements in WITH clause
 drop table t1,t2;
 #
 # Bug mdev-9937: View used in the specification of with table 

mysql-test/r/cte_recursive.result

@@ -160,6 +160,8 @@ insert into folks values
 (6, 'Grandgrandma Martha', '1923-05-17', null, null),
 (67, 'Cousin Eddie', '1992-02-28', 25, 27),
 (27, 'Auntie Melinda', '1971-03-29', null, null);
+# simple recursion with one anchor and one recursive select
+# the anchor is the first select in the specification 
 with recursive 
 ancestors
 as
@@ -182,6 +184,8 @@ id	name	dob	father	mother
 7	Grandma Sally	1943-08-23	NULL	6
 8	Grandpa Ben	1940-10-21	NULL	NULL
 6	Grandgrandma Martha	1923-05-17	NULL	NULL
+# simple recursion with one anchor and one recursive select
+# the anchor is the last select in the specification 
 with recursive 
 ancestors
 as
@@ -204,6 +208,8 @@ id	name	dob	father	mother
 7	Grandma Sally	1943-08-23	NULL	6
 8	Grandpa Ben	1940-10-21	NULL	NULL
 6	Grandgrandma Martha	1923-05-17	NULL	NULL
+# simple recursion with one anchor and one recursive select
+# the anchor is the first select in the specification 
 with recursive
 ancestors
 as
@@ -224,29 +230,7 @@ id	name	dob	father	mother
 7	Grandma Sally	1943-08-23	NULL	6
 8	Grandpa Ben	1940-10-21	NULL	NULL
 6	Grandgrandma Martha	1923-05-17	NULL	NULL
-with recursive
+# two recursive definition, one uses another
-ancestors
-as
-(
-select *
-from  folks
-where name = 'Me' or name='Sister Amy'
-  union 
-select  p.*
-from folks as p, ancestors as a
-where p.id = a.father or p.id = a.mother
-)
-select * from ancestors;
-id	name	dob	father	mother
-100	Me	2000-01-01	20	30
-98	Sister Amy	2001-06-20	20	30
-20	Dad	1970-02-02	10	9
-30	Mom	1975-03-03	8	7
-10	Grandpa Bill	1940-04-05	NULL	NULL
-9	Grandma Ann	1941-10-15	NULL	NULL
-7	Grandma Sally	1943-08-23	NULL	6
-8	Grandpa Ben	1940-10-21	NULL	NULL
-6	Grandgrandma Martha	1923-05-17	NULL	NULL
 with recursive 
 prev_gen
 as
@@ -282,6 +266,50 @@ Grandma Ann	1941-10-15
 Grandma Sally	1943-08-23
 Grandpa Ben	1940-10-21
 Grandgrandma Martha	1923-05-17
+# recursive definition with two attached non-recursive
+with recursive 
+ancestors(id,name,dob)
+as
+(
+with 
+father(child_id,id,name,dob)
+as
+(
+select folks.id, f.id, f.name, f.dob
+from folks, folks f
+where folks.father=f.id 
+),
+mother(child_id,id,name,dob)
+as
+(
+select folks.id, m.id, m.name, m.dob
+from folks, folks m
+where folks.mother=m.id 
+)  
+select folks.id, folks.name, folks.dob
+from folks
+where name='Me'
+  union 
+select f.id, f.name, f.dob
+from ancestors a, father f
+where f.child_id=a.id
+union 
+select m.id, m.name, m.dob
+from ancestors a, mother m
+where m.child_id=a.id
+)
+select ancestors.name, ancestors.dob from ancestors;
+name	dob
+Me	2000-01-01
+Dad	1970-02-02
+Mom	1975-03-03
+Grandpa Bill	1940-04-05
+Grandpa Ben	1940-10-21
+Grandma Ann	1941-10-15
+Grandma Sally	1943-08-23
+Grandgrandma Martha	1923-05-17
+# simple recursion with one anchor and one recursive select
+# the anchor is the first select in the specification 
 with recursive
 descendants
 as
@@ -300,6 +328,8 @@ id	name	dob	father	mother
 20	Dad	1970-02-02	10	9
 100	Me	2000-01-01	20	30
 98	Sister Amy	2001-06-20	20	30
+# simple recursion with one anchor and one recursive select
+# the anchor is the first select in the specification 
 with recursive
 descendants
 as
@@ -320,6 +350,7 @@ id	name	dob	father	mother
 100	Me	2000-01-01	20	30
 98	Sister Amy	2001-06-20	20	30
 67	Cousin Eddie	1992-02-28	25	27
+# simple recursive table used three times in the main query
 with recursive
 ancestors
 as
@@ -340,6 +371,7 @@ id	name	dob	father	mother	id	name	dob	father	mother
 20	Dad	1970-02-02	10	9	30	Mom	1975-03-03	8	7
 10	Grandpa Bill	1940-04-05	NULL	NULL	9	Grandma Ann	1941-10-15	NULL	NULL
 8	Grandpa Ben	1940-10-21	NULL	NULL	7	Grandma Sally	1943-08-23	NULL	6
+# simple recursive table used three times in the main query
 with 
 ancestor_couples(husband, h_dob, wife, w_dob)
 as
@@ -366,6 +398,7 @@ husband	h_dob	wife	w_dob
 Dad	1970-02-02	Mom	1975-03-03
 Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
 Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# simple recursion with two selects in recursive part
 with recursive
 ancestors
 as
@@ -392,6 +425,7 @@ id	name	dob	father	mother
 9	Grandma Ann	1941-10-15	NULL	NULL
 7	Grandma Sally	1943-08-23	NULL	6
 6	Grandgrandma Martha	1923-05-17	NULL	NULL
+# mutual recursion with renaming
 with recursive
 ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
 w_id, w_name, w_dob, w_father, w_mother)
@@ -421,6 +455,7 @@ h_name	h_dob	w_name	w_dob
 Dad	1970-02-02	Mom	1975-03-03
 Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
 Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# mutual recursion with union all
 with recursive
 ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
 w_id, w_name, w_dob, w_father, w_mother)
@@ -450,6 +485,37 @@ h_name	h_dob	w_name	w_dob
 Dad	1970-02-02	Mom	1975-03-03
 Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
 Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# mutual recursion with renaming
+with recursive
+ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
+w_id, w_name, w_dob, w_father, w_mother)
+as
+(
+select h.*, w.*
+from folks h, folks w,  coupled_ancestors a
+where a.father = h.id AND a.mother = w.id
+union
+select h.*, w.*
+from folks v, folks h, folks w
+where v.name = 'Me' and
+(v.father = h.id AND v.mother= w.id)
+),
+coupled_ancestors (id, name, dob, father, mother)
+as
+(
+select h_id, h_name, h_dob, h_father, h_mother
+from ancestor_couples
+union
+select w_id, w_name, w_dob, w_father, w_mother
+from ancestor_couples
+)
+select h_name, h_dob, w_name, w_dob
+from ancestor_couples;
+h_name	h_dob	w_name	w_dob
+Dad	1970-02-02	Mom	1975-03-03
+Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
+Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# mutual recursion with union all
 with recursive
 ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
 w_id, w_name, w_dob, w_father, w_mother)
@@ -478,6 +544,7 @@ h_name	h_dob	w_name	w_dob
 Dad	1970-02-02	Mom	1975-03-03
 Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
 Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# mutual recursion with one select in the first definition
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -507,6 +574,7 @@ h_id	w_id
 20	30
 10	9
 8	7
+# join of a mutually recursive table with base tables
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -537,6 +605,7 @@ name	dob	name	dob
 Dad	1970-02-02	Mom	1975-03-03
 Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
 Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# join of two mutually recursive tables
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -607,6 +676,7 @@ NULL	UNION RESULT	<union3,4,5>	ALL	NULL	NULL	NULL	NULL	NULL	NULL
 2	UNCACHEABLE SUBQUERY	<derived3>	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
 Warnings:
 Note	1003	with recursive ancestor_couple_ids as (select `a`.`father` AS `h_id`,`a`.`mother` AS `w_id` from `coupled_ancestors` `a` where ((`a`.`father` is not null) and (`a`.`mother` is not null)))coupled_ancestors as (select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where (`test`.`folks`.`name` = 'Me') union all select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `fa` where (`test`.`p`.`id` = `fa`.`h_id`) union all select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `ma` where (`test`.`p`.`id` = `ma`.`w_id`)), select `h`.`name` AS `name`,`h`.`dob` AS `dob`,`w`.`name` AS `name`,`w`.`dob` AS `dob` from `ancestor_couple_ids` `c` join `coupled_ancestors` `h` join `coupled_ancestors` `w` where ((`h`.`id` = `c`.`h_id`) and (`w`.`id` = `c`.`w_id`))
+# simple mutual recursion
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -640,6 +710,7 @@ NULL	NULL
 NULL	NULL
 NULL	6
 NULL	NULL
+# join of two mutually recursive tables
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -669,6 +740,7 @@ name	dob	name	dob
 Dad	1970-02-02	Mom	1975-03-03
 Grandpa Bill	1940-04-05	Grandma Ann	1941-10-15
 Grandpa Ben	1940-10-21	Grandma Sally	1943-08-23
+# execution of prepared query using a recursive table
 prepare stmt1 from "
 with recursive 
 ancestors
@@ -705,6 +777,7 @@ id	name	dob	father	mother
 8	Grandpa Ben	1940-10-21	NULL	NULL
 6	Grandgrandma Martha	1923-05-17	NULL	NULL
 deallocate prepare stmt1;
+# view using a recursive table
 create view v1 as
 with recursive 
 ancestors
@@ -786,6 +859,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
 Note	1003	with recursive ancestors as (select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where ((`test`.`folks`.`name` = 'Me') and (`test`.`folks`.`dob` = DATE'2000-01-01')) union select `p`.`id` AS `id`,`p`.`name` AS `name`,`p`.`dob` AS `dob`,`p`.`father` AS `father`,`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestors` `a` where ((`a`.`father` = `p`.`id`) or (`a`.`mother` = `p`.`id`)))select `ancestors`.`id` AS `id`,`ancestors`.`name` AS `name`,`ancestors`.`dob` AS `dob`,`ancestors`.`father` AS `father`,`ancestors`.`mother` AS `mother` from `ancestors`
+# recursive spec with two anchor selects and two recursive ones 
 with recursive
 ancestor_ids (id)
 as
@@ -813,6 +887,7 @@ id	name	dob	father	mother
 7	Grandma Sally	1943-08-23	NULL	6
 8	Grandpa Ben	1940-10-21	NULL	NULL
 6	Grandgrandma Martha	1923-05-17	NULL	NULL
+# recursive spec using union all 
 with recursive
 ancestors
 as
@@ -1115,6 +1190,7 @@ generation	name
 2	Grandma Ann
 2	Grandma Sally
 2	Grandpa Ben
+# query with recursive tables using key access
 alter table folks add primary key (id);
 explain
 with recursive

mysql-test/t/cte_nonrecursive.test

@@ -469,6 +469,20 @@ explain
 with t as (select a, count(*) from t1 where b >= 'c' group by a)
   select t1.b from t2,t1 where t1.a = t2.c;
 
+--echo # too many with elements in with clause
+let $m= 65;
+let $i= $m;
+dec $i;
+let $q= with s$m as (select * from t1);
+while ($i)
+{
+  let $q= $q, s$i as (select * from t1) ;
+  dec $i;
+ }
+let $q= $q select * from s$m;
+--ERROR ER_TOO_MANY_DEFINITIONS_IN_WITH_CLAUSE
+eval $q;
+
 drop table t1,t2;
 
 --echo #

mysql-test/t/cte_recursive.test

@@ -156,7 +156,8 @@ insert into folks values
 (67, 'Cousin Eddie', '1992-02-28', 25, 27),
 (27, 'Auntie Melinda', '1971-03-29', null, null); 
 
-
+--echo # simple recursion with one anchor and one recursive select
+--echo # the anchor is the first select in the specification 
 with recursive 
 ancestors
 as
@@ -171,6 +172,8 @@ as
 )
 select * from ancestors;
 
+--echo # simple recursion with one anchor and one recursive select
+--echo # the anchor is the last select in the specification 
 with recursive 
 ancestors
 as
@@ -185,6 +188,8 @@ as
 )
 select * from ancestors;
 
+--echo # simple recursion with one anchor and one recursive select
+--echo # the anchor is the first select in the specification 
 with recursive
 ancestors
 as
@@ -199,20 +204,8 @@ as
 )
 select * from ancestors;
 
-with recursive
-ancestors
-as
-(
-  select *
-    from  folks
-      where name = 'Me' or name='Sister Amy'
-  union 
-  select  p.*
-    from folks as p, ancestors as a
-  where p.id = a.father or p.id = a.mother
-)
-select * from ancestors;
 
+--echo # two recursive definition, one uses another
 with recursive 
 prev_gen
 as
@@ -240,7 +233,45 @@ as
 )
 select ancestors.name, ancestors.dob from ancestors;
 
+--echo # recursive definition with two attached non-recursive
+with recursive 
+ancestors(id,name,dob)
+as
+(
+  with 
+  father(child_id,id,name,dob)
+  as
+  (
+    select folks.id, f.id, f.name, f.dob
+      from folks, folks f
+        where folks.father=f.id 
         
+  ),
+  mother(child_id,id,name,dob)
+  as
+  (
+    select folks.id, m.id, m.name, m.dob
+      from folks, folks m
+        where folks.mother=m.id 
+        
+  )  
+  select folks.id, folks.name, folks.dob
+    from folks
+      where name='Me'
+  union 
+  select f.id, f.name, f.dob
+    from ancestors a, father f
+      where f.child_id=a.id
+  union 
+  select m.id, m.name, m.dob
+    from ancestors a, mother m
+      where m.child_id=a.id
+  
+)
+select ancestors.name, ancestors.dob from ancestors;
+
+--echo # simple recursion with one anchor and one recursive select
+--echo # the anchor is the first select in the specification 
 with recursive
 descendants
 as
@@ -255,6 +286,8 @@ as
 )
 select * from descendants;
 
+--echo # simple recursion with one anchor and one recursive select
+--echo # the anchor is the first select in the specification 
 with recursive
 descendants
 as
@@ -270,6 +303,7 @@ as
 select * from descendants;
 
 
+--echo # simple recursive table used three times in the main query
 with recursive
 ancestors
 as
@@ -287,6 +321,8 @@ select *
     where exists (select * from ancestors a 
                   where a.father=t1.id AND a.mother=t2.id);
 
+
+--echo # simple recursive table used three times in the main query
 with 
 ancestor_couples(husband, h_dob, wife, w_dob)
 as
@@ -310,6 +346,8 @@ select t1.name, t1.dob, t2.name, t2.dob
 )
 select * from ancestor_couples;
 
+
+--echo # simple recursion with two selects in recursive part
 with recursive
 ancestors
 as
@@ -328,6 +366,8 @@ as
 )
 select * from ancestors;
 
+
+--echo # mutual recursion with renaming
 with recursive
 ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
                  w_id, w_name, w_dob, w_father, w_mother)
@@ -355,6 +395,7 @@ select h_name, h_dob, w_name, w_dob
   from ancestor_couples;
 
 
+--echo # mutual recursion with union all
 with recursive
 ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
                  w_id, w_name, w_dob, w_father, w_mother)
@@ -382,6 +423,35 @@ select h_name, h_dob, w_name, w_dob
   from ancestor_couples;
 
 
+--echo # mutual recursion with renaming
+with recursive
+ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
+                 w_id, w_name, w_dob, w_father, w_mother)
+as
+(
+  select h.*, w.*
+    from folks h, folks w,  coupled_ancestors a
+      where a.father = h.id AND a.mother = w.id
+  union
+  select h.*, w.*
+    from folks v, folks h, folks w
+      where v.name = 'Me' and
+            (v.father = h.id AND v.mother= w.id)
+),
+coupled_ancestors (id, name, dob, father, mother)
+as
+(
+  select h_id, h_name, h_dob, h_father, h_mother
+    from ancestor_couples
+  union
+  select w_id, w_name, w_dob, w_father, w_mother
+    from ancestor_couples
+)
+select h_name, h_dob, w_name, w_dob
+  from ancestor_couples;
+
+
+--echo # mutual recursion with union all
 with recursive
 ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
                  w_id, w_name, w_dob, w_father, w_mother)
@@ -407,7 +477,7 @@ as
 select h_name, h_dob, w_name, w_dob
   from ancestor_couples;
 
-
+--echo # mutual recursion with one select in the first definition
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -434,6 +504,8 @@ as
 select *
   from ancestor_couple_ids;
 
+
+--echo # join of a mutually recursive table with base tables
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -462,6 +534,7 @@ select h.name, h.dob, w.name, w.dob
     where c.h_id = h.id and c.w_id= w.id;
 
 
+--echo # join of two mutually recursive tables
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -517,6 +590,8 @@ select h.name, h.dob, w.name, w.dob
   from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
     where c.h_id = h.id and c.w_id= w.id;
 
+
+--echo # simple mutual recursion
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -543,6 +618,7 @@ select *
   from ancestor_couple_ids;
 
 
+--echo # join of two mutually recursive tables
 with recursive
 ancestor_couple_ids(h_id, w_id)
 as
@@ -570,6 +646,7 @@ select h.name, h.dob, w.name, w.dob
     where c.h_id = h.id and c.w_id= w.id;
 
 
+--echo # execution of prepared query using a recursive table
 prepare stmt1 from "
 with recursive 
 ancestors
@@ -592,6 +669,7 @@ execute stmt1;
 deallocate prepare stmt1;
 
 
+--echo # view using a recursive table
 create view v1 as
 with recursive 
 ancestors
@@ -636,6 +714,7 @@ select * from v2;
 
 drop view v1,v2;
 
+
 explain extended
 with recursive 
 ancestors
@@ -652,6 +731,7 @@ as
 select * from ancestors;
 
 
+--echo # recursive spec with two anchor selects and two recursive ones 
 with recursive
 ancestor_ids (id)
 as
@@ -672,6 +752,8 @@ as
 )
 select * from ancestors;
 
+
+--echo # recursive spec using union all 
 with recursive
 ancestors
 as
@@ -691,8 +773,6 @@ as
 select * from ancestors;
 
 
-
-
 --ERROR ER_NOT_STANDARDS_COMPLIANT_RECURSIVE
 with recursive
 ancestor_ids (id, generation)
@@ -937,6 +1017,8 @@ as
 )
 select * from ancestors;
 
+--echo # query with recursive tables using key access
+
 alter table folks add primary key (id);
 
 explain
@@ -958,6 +1040,7 @@ as
 )
 select * from ancestors;
 
+
 with recursive
 ancestors
 as

sql/share/errmsg-utf8.txt

@@ -7150,6 +7150,8 @@ ER_BAD_COMMAND_IN_MULTI
         ukr "Команда '%s' не дозволена для COM_MULTI"
 ER_WITH_COL_WRONG_LIST
         eng "WITH column list and SELECT field list have different column counts"
+ER_TOO_MANY_DEFINITIONS_IN_WITH_CLAUSE
+        eng "Too many WITH elements in WITH clause"
 ER_DUP_QUERY_NAME
         eng "Duplicate query name in WITH clause"
 ER_RECURSIVE_WITHOUT_ANCHORS

sql/sql_class.h

@@ -4681,8 +4681,11 @@ public:
 class select_union_recursive :public select_union
 {
  public:
+  /* The temporary table with the new records generated by one iterative step */
   TABLE *incr_table;
+  /* One of tables from the list rec_tables (determined dynamically) */
   TABLE *first_rec_table_to_update;
+  /* The temporary tables used for recursive table references */
   List<TABLE> rec_tables;
 
   select_union_recursive(THD *thd_arg):

sql/sql_cte.cc

@@ -6,6 +6,38 @@
 #include "sql_select.h"
 
 
+/**
+  @brief
+    Add a new element to this with clause 
+
+  @param elem  The with element to add to this with clause
+
+  @details
+    The method adds the with element 'elem' to the elements
+    in this with clause. The method reports an error if
+    the number of the added element exceeds the value
+    of the constant max_number_of_elements_in_with_clause.
+
+  @retval
+    true    if an error is reported 
+    false   otherwise
+*/
+  
+bool With_clause::add_with_element(With_element *elem)
+{ 
+  if (with_list.elements == max_number_of_elements_in_with_clause)
+  {
+    my_error(ER_TOO_MANY_DEFINITIONS_IN_WITH_CLAUSE, MYF(0));
+    return true;
+  }
+  elem->owner= this;
+  elem->number= with_list.elements;
+  elem->spec->with_element= elem;
+  with_list.link_in_list(elem, &elem->next);
+  return false;
+}
+
+
 /**
   @brief
     Check dependencies between tables defined in a list of with clauses

sql/sql_cte.h

@@ -210,6 +210,8 @@ public:
   friend class With_clause;
 };
 
+const uint max_number_of_elements_in_with_clause= sizeof(table_map)*8;
+
 /**
   @class With_clause
   @brief Set of with_elements
@@ -270,15 +272,7 @@ public:
       with_recursive(recursive_fl)
   { }
 
-  /* Add a new element to the current with clause */ 
+  bool add_with_element(With_element *elem);
-  bool add_with_element(With_element *elem)
-  { 
-    elem->owner= this;
-    elem->number= with_list.elements;
-    elem->spec->with_element= elem;
-    with_list.link_in_list(elem, &elem->next);
-    return false;
-  }
 
   /* Add this with clause to the list of with clauses used in the statement */
   void add_to_list(With_clause ** &last_next)

sql/sql_derived.cc

@@ -644,16 +644,21 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
   if (unit->prepared && derived->is_recursive_with_table() &&
       !derived->table)
   {
+    /* 
+      Here 'derived' is either a non-recursive table reference to a recursive
+      with table or a recursive table reference to a recursvive table whose
+      specification has been already prepared (a secondary recursive table
+      reference.
+    */ 
     if (!(derived->derived_result= new (thd->mem_root) select_union(thd)))
       DBUG_RETURN(TRUE); // out of memory
     thd->create_tmp_table_for_derived= TRUE;
-    if (!derived->table)
+    res= derived->derived_result->create_result_table(
-      res= derived->derived_result->create_result_table(
+                                  thd, &unit->types, FALSE,
-                                    thd, &unit->types, FALSE,
+                                  (first_select->options |
-                                    (first_select->options |
+                                   thd->variables.option_bits |
-                                     thd->variables.option_bits |
+                                   TMP_TABLE_ALL_COLUMNS),
-                                     TMP_TABLE_ALL_COLUMNS),
+                                  derived->alias, FALSE, FALSE);
-                                    derived->alias, FALSE, FALSE);
     thd->create_tmp_table_for_derived= FALSE;
 
     if (!res && !derived->table)
@@ -662,6 +667,7 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
       derived->table= derived->derived_result->table;
       if (derived->is_with_table_recursive_reference())
       {
+        /* Here 'derived" is a secondary recursive table reference */
         unit->with_element->rec_result->rec_tables.push_back(derived->table);
       }
     }
@@ -685,7 +691,12 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
         (!derived->with->with_anchor && 
          !derived->with->is_with_prepared_anchor()))
     {
-      // Prepare underlying views/DT first.
+      /* 
+        Prepare underlying views/DT first unless 'derived' is a recursive
+        table reference and either the anchors from the specification of
+        'derived' has been already prepared or there no anchor in this
+        specification
+      */  
       if ((res= sl->handle_derived(lex, DT_PREPARE)))
         goto exit;
     }
@@ -922,29 +933,40 @@ bool mysql_derived_create(THD *thd, LEX *lex, TABLE_LIST *derived)
 }
 
 
+/**
+  @brief
+    Fill the recursive with table 
+
+  @param thd  The thread handle
+
+  @details
+    The method is called only for recursive with tables. 
+    The method executes the recursive part of the specification
+    of this with table until no more rows are added to the table
+    or the number of the performed iteration reaches the allowed
+    maximum. 
+
+  @retval
+    false   on success
+    true    on failure 
+*/
+
 bool TABLE_LIST::fill_recursive(THD *thd)
 {
   bool rc= false;
   st_select_lex_unit *unit= get_unit();
-  if (is_with_table_recursive_reference())
+  rc= with->instantiate_tmp_tables();
+  while (!rc && !with->all_are_stabilized())
   {
+    if (with->level > thd->variables.max_recursive_iterations)
+      break;
+    with->prepare_for_next_iteration();
     rc= unit->exec_recursive();
   }
-  else
+  if (!rc)
   {
-    rc= with->instantiate_tmp_tables();
+    TABLE *src= with->rec_result->table;
-    while (!rc && !with->all_are_stabilized())
+    rc =src->insert_all_rows_into(thd, table, true);
-    {
-      if (with->level > thd->variables.max_recursive_iterations)
-        break;
-      with->prepare_for_next_iteration();
-      rc= unit->exec_recursive();
-    }
-    if (!rc)
-    {
-      TABLE *src= with->rec_result->table;
-      rc =src->insert_all_rows_into(thd, table, true);
-    } 
   } 
   return rc;
 }
@@ -960,9 +982,10 @@ bool TABLE_LIST::fill_recursive(THD *thd)
 
   @details
   Execute subquery of given 'derived' table/view and fill the result
-  table. After result table is filled, if this is not the EXPLAIN statement,
+  table. After result table is filled, if this is not the EXPLAIN statement
-  the entire unit / node is deleted. unit is deleted if UNION is used
+  and the table is not specified with a recursion the entire unit / node
-  for derived table and node is deleted is it is a simple SELECT.
+  is deleted. unit is deleted if UNION is used  for derived table and node
+  is deleted is it is a simple SELECT.
   'lex' is unused and 'thd' is passed as an argument to an underlying function.
 
   @note
@@ -986,13 +1009,21 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
     DBUG_RETURN(FALSE);
   /*check that table creation passed without problems. */
   DBUG_ASSERT(derived->table && derived->table->is_created());
-  SELECT_LEX *first_select= unit->first_select();
   select_union *derived_result= derived->derived_result;
   SELECT_LEX *save_current_select= lex->current_select;
   
   if (derived_is_recursive)
   {
-    res= derived->fill_recursive(thd);
+    if (derived->is_with_table_recursive_reference())
+    {
+      /* Here only one iteration step is performed */
+      res= unit->exec_recursive();
+    }
+    else
+    {
+      /* In this case all iteration are performed */
+      res= derived->fill_recursive(thd);
+    }
   }
   else if (unit->is_union())
   {
@@ -1001,6 +1032,7 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
   }
   else
   {
+    SELECT_LEX *first_select= unit->first_select();
     unit->set_limit(unit->global_parameters());
     if (unit->select_limit_cnt == HA_POS_ERROR)
       first_select->options&= ~OPTION_FOUND_ROWS;

sql/sql_union.cc

@@ -100,6 +100,7 @@ int select_union::send_data(List<Item> &values)
   return 0;
 }
 
+
 int select_union_recursive::send_data(List<Item> &values)
 {
   int rc= select_union::send_data(values);
@@ -1166,7 +1167,29 @@ err:
 }
 
 
-// One step of recursive execution
+/**
+  @brief
+    Execute the union of the specification of a recursive with table 
+
+  @details
+    The method is performed only for the units that are specifications
+    if recursive with table T. If the specification contains an anchor
+    part then the first call of this method executes only this part
+    while the following calls execute the recursive part. If there are
+    no anchors each call executes the whole unit.
+    Before the excution the method cleans up the temporary table 
+    to where the new rows of the recursive table are sent.
+    After the execution the unit these rows are copied to the 
+    temporary tables created for recursive references of T. 
+    If the specification if T is restricted (standards compliant)
+    then these temporary tables are cleaned up before new rows
+    are copied into them.  
+
+  @retval
+    false   on success
+    true    on failure
+*/
+
 bool st_select_lex_unit::exec_recursive()
 {
   st_select_lex *lex_select_save= thd->lex->current_select;