create table t1 (a int, b varchar(32));
insert into t1 values
(4,'aaaa' ), (7,'bb'), (1,'ccc'), (4,'dd');
insert into t1 values
(3,'eee'), (7,'bb'), (1,'fff'), (4,'ggg');

--ERROR ER_UNACCEPTABLE_MUTUAL_RECURSION
with recursive
t as 
(
  select * from t1 where t1.b >= 'c'
  union
  select * from r
),
r as
(
  select * from t
  union
  select t1.* from t1,r where r.a+1 = t1.a
)
select * from r;


--ERROR ER_UNACCEPTABLE_MUTUAL_RECURSION
with recursive
a1(a,b) as
(select * from t1 where t1.a>3
union
select * from b1 where b1.a >3
union
select * from c1 where c1.a>3),
b1(a,b) as
(select * from a1 where a1.b > 'ccc'
union
select * from c1 where c1.b > 'ddd'),
c1(a,b) as
(select * from a1 where a1.a<6 and a1.b< 'zz'
union
select * from b1 where b1.b > 'auu')
select * from c1; 

drop table t1;


--echo # WITH RECURSIVE vs just WITH

create table t1 (a int);
insert into t1 values
  (0), (1), (2), (3), (4);
create table t2 (a int);
insert into t2 values
  (1), (2), (3), (4), (5);


--echo # just WITH : s refers to t defined after s
--ERROR ER_NO_SUCH_TABLE
with 
 s(a) as (select t.a + 10 from t),
 t(a) as (select t1.a from t1)
select * from s;

--echo # WITH RECURSIVE: s refers to t defined after s
with recursive 
 s(a) as (select t.a + 10 from t),
 t(a) as (select t1.a from t1)
select * from s;

--echo # just WITH : defined t1 is non-recursive and uses base tables t1,t2
with
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;

explain
with
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;


--echo #WITH RECURSIVE : defined t1 is recursive and uses only base table t2
with recursive
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;

explain
with recursive
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;
    
--echo # just WITH : types of t1 columns are determined by all parts of union 

create view v1 as
with
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a+1 from t1,t2 where t1.a=t2.a
)
select * from t1;

show columns from v1;


--echo # WITH RECURSIVE : types of t1 columns are determined by anchor parts 

create view v2 as
with recursive
t1 as
(
select a  from t2 where t2.a=3
union
select t2.a+1 from t1,t2 where t1.a=t2.a
)
select * from t1;

show columns from v2;

drop view v1,v2;

drop table t1,t2;


create table  folks(id int, name char(32), dob date, father int, mother int);

insert into folks values
(100, 'Me', '2000-01-01', 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),
(25, 'Uncle Jim', '1968-11-18', 8, 7),
(98, 'Sister Amy', '2001-06-20', 20, 30),
(7, 'Grandma Sally', '1943-08-23', null, 6),
(8, 'Grandpa Ben', '1940-10-21', null, null),
(6, 'Grandgrandma Martha', '1923-05-17', null, null),
(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
(
  select *
    from folks
      where name = 'Me' and dob = '2000-01-01'
  union 
  select p.id, p.name, p.dob, p.father, p.mother
    from folks as p, ancestors AS a
      where p.id = a.father or p.id = a.mother
)
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
(
  select p.*
    from folks as p, ancestors AS a
      where p.id = a.father or p.id = a.mother
  union
  select *
    from folks
      where name = 'Me' and dob = '2000-01-01'
)
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
(
  select *
    from folks
      where name = 'Cousin Eddie'
  union 
  select p.*
    from folks as p, ancestors as a
      where p.id = a.father or p.id = a.mother
)
select * from ancestors;

--echo # simple recursion with or in anchor and or in recursive part 
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
(
  select folks.*
    from folks, prev_gen
      where folks.id=prev_gen.father or folks.id=prev_gen.mother
  union
  select * 
    from folks
      where name='Me'
),
ancestors
as
(
  select *
    from folks
      where name='Me'
  union 
  select *
    from ancestors
  union
    select *
     from prev_gen
)
select ancestors.name, ancestors.dob from ancestors;

--echo # recursive definition with two attached non-recursive
#MXS qc_sqlite
#MXS qc_get_function_info     : ERR: =(folks.name, folks.father, folks.id, folks.mother, mother.child_id, ancestors.id, father.child_id) != =(mother.child_id, ancestors.id, folks.father, folks.id, folks.mother, mother.id, father.child_id, name)
#MXS The reported function arguments to '=' are disjoint. The relevant are there though (folks.*).
#MXS with recursive 
#MXS ancestors(id,name,dob)
#MXS as
#MXS (
#MXS   with 
#MXS   father(child_id,id,name,dob)
#MXS   as
#MXS   (
#MXS     select folks.id, f.id, f.name, f.dob
#MXS       from folks, folks f
#MXS         where folks.father=f.id 
#MXS         
#MXS   ),
#MXS   mother(child_id,id,name,dob)
#MXS   as
#MXS   (
#MXS     select folks.id, m.id, m.name, m.dob
#MXS       from folks, folks m
#MXS         where folks.mother=m.id 
#MXS         
#MXS   )  
#MXS   select folks.id, folks.name, folks.dob
#MXS     from folks
#MXS       where name='Me'
#MXS   union 
#MXS   select f.id, f.name, f.dob
#MXS     from ancestors a, father f
#MXS       where f.child_id=a.id
#MXS   union 
#MXS   select m.id, m.name, m.dob
#MXS     from ancestors a, mother m
#MXS       where m.child_id=a.id
#MXS   
#MXS )
#MXS 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
(
  select *
    from folks
      where name = 'Grandpa Bill'
  union 
  select folks.*
    from folks, descendants as d
      where d.id=folks.father or d.id=folks.mother
)
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
(
  select *
    from folks
      where name = 'Grandma Sally'
  union 
  select folks.*
    from folks, descendants as d
      where d.id=folks.father or d.id=folks.mother
)
select * from descendants;


--echo # simple recursive table used three times in the main query
with recursive
ancestors
as
(
  select *
    from folks 
      where name = 'Me' and dob = '2000-01-01'
  union
  select p.*   
    from folks as p, ancestors AS a   
      where p.id = a.father OR p.id = a.mother
)
select *
  from ancestors t1, ancestors t2 
    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
(
with recursive 
ancestors
as
(
  select *
    from folks 
       where name = 'Me'
  union
  select p.*   
    from folks as p, ancestors AS a   
      where p.id = a.father OR p.id = a.mother
)
select t1.name, t1.dob, t2.name, t2.dob
  from ancestors t1, ancestors t2 
    where exists (select * from ancestors a 
                    where a.father=t1.id AND a.mother=t2.id)
)
select * from ancestor_couples;


--echo # simple recursion with two selects in recursive part
with recursive
ancestors
as
(
  select *
    from folks 
      where name = 'Me'
  union 
  select p.*
    from folks as p, ancestors as fa
      where p.id = fa.father
  union
  select p.*
    from folks as p, ancestors as ma
      where p.id = ma.mother
)
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)
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
#MXS qc_mysqlembedded and qc_sqlite disagree in the used fields.
#MXS Both return correctly the folks fields (i.e. the real ones),
#MXS but disagree on the fields of the CTE tables.
#
#MXS with recursive
#MXS ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
#MXS                  w_id, w_name, w_dob, w_father, w_mother)
#MXS as
#MXS (
#MXS   select h.*, w.*
#MXS     from folks h, folks w,  coupled_ancestors a
#MXS       where a.father = h.id AND a.mother = w.id
#MXS   union 
#MXS   select h.*, w.*
#MXS     from folks v, folks h, folks w
#MXS       where v.name = 'Me' and
#MXS             (v.father = h.id AND v.mother= w.id)
#MXS ),
#MXS coupled_ancestors (id, name, dob, father, mother)
#MXS as
#MXS (
#MXS   select h_id, h_name, h_dob, h_father, h_mother
#MXS     from ancestor_couples
#MXS   union all
#MXS   select w_id, w_name, w_dob, w_father, w_mother
#MXS     from ancestor_couples
#MXS )
#MXS select h_name, h_dob, w_name, w_dob
#MXS   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
#MXS qc_mysqlembedded and qc_sqlite disagree in the used fields.
#MXS Both return correctly the folks fields (i.e. the real ones),
#MXS but disagree on the fields of the CTE tables.
#
#MXS with recursive
#MXS ancestor_couples(h_id, h_name, h_dob, h_father, h_mother,
#MXS                  w_id, w_name, w_dob, w_father, w_mother)
#MXS as
#MXS (
#MXS   select h.*, w.*
#MXS     from folks h, folks w,  coupled_ancestors a
#MXS       where a.father = h.id AND a.mother = w.id
#MXS ),
#MXS coupled_ancestors (id, name, dob, father, mother)
#MXS as
#MXS (
#MXS   select * 
#MXS     from folks 
#MXS       where name = 'Me'
#MXS   union all
#MXS   select h_id, h_name, h_dob, h_father, h_mother
#MXS     from ancestor_couples
#MXS   union all
#MXS   select w_id, w_name, w_dob, w_father, w_mother
#MXS     from ancestor_couples
#MXS )
#MXS select h_name, h_dob, w_name, w_dob
#MXS   from ancestor_couples;

--echo # mutual recursion with one select in the first definition
#MXS qc_mysqlembedded and qc_sqlite disagree in the used fields.
#MXS Both return correctly the folks fields (i.e. the real ones),
#MXS but disagree on the fields of the CTE tables.
#
#MXS with recursive
#MXS ancestor_couple_ids(h_id, w_id)
#MXS as
#MXS (
#MXS   select a.father, a.mother
#MXS     from coupled_ancestors a
#MXS       where a.father is not null and a.mother is not null
#MXS ),
#MXS coupled_ancestors (id, name, dob, father, mother)
#MXS as
#MXS (
#MXS   select * 
#MXS     from folks 
#MXS       where name = 'Me'
#MXS   union all
#MXS   select p.*
#MXS     from folks p, ancestor_couple_ids fa
#MXS       where p.id = fa.h_id
#MXS   union all
#MXS   select p.*
#MXS     from folks p, ancestor_couple_ids ma
#MXS       where p.id = ma.w_id
#MXS )
#MXS select *
#MXS   from ancestor_couple_ids;


--echo # join of a mutually recursive table with base tables
#MXS qc_mysqlembedded and qc_sqlite disagree in the used fields.
#MXS Both return correctly the folks fields (i.e. the real ones),
#MXS but disagree on the fields of the CTE tables.
#
#MXS with recursive
#MXS ancestor_couple_ids(h_id, w_id)
#MXS as
#MXS (
#MXS   select a.father, a.mother
#MXS     from coupled_ancestors a
#MXS       where a.father is not null and a.mother is not null
#MXS ),
#MXS coupled_ancestors (id, name, dob, father, mother)
#MXS as
#MXS (
#MXS   select * 
#MXS     from folks 
#MXS       where name = 'Me'
#MXS   union all
#MXS   select p.*
#MXS     from folks p, ancestor_couple_ids fa
#MXS       where p.id = fa.h_id
#MXS   union all
#MXS   select p.*
#MXS     from folks p, ancestor_couple_ids ma
#MXS       where p.id = ma.w_id
#MXS )
#MXS select h.name, h.dob, w.name, w.dob
#MXS   from ancestor_couple_ids c, folks h, folks w
#MXS     where c.h_id = h.id and c.w_id= w.id;


--echo # join of two mutually recursive tables
#MXS qc_mysqlembedded and qc_sqlite disagree in the used fields.
#MXS Both return correctly the folks fields (i.e. the real ones),
#MXS but disagree on the fields of the CTE tables.
#
#MXS with recursive
#MXS ancestor_couple_ids(h_id, w_id)
#MXS as
#MXS (
#MXS   select a.father, a.mother
#MXS     from coupled_ancestors a
#MXS       where a.father is not null and a.mother is not null
#MXS ),
#MXS coupled_ancestors (id, name, dob, father, mother)
#MXS as
#MXS (
#MXS   select * 
#MXS     from folks 
#MXS       where name = 'Me'
#MXS   union all
#MXS   select p.*
#MXS     from folks p, ancestor_couple_ids fa
#MXS       where p.id = fa.h_id
#MXS   union all
#MXS   select p.*
#MXS     from folks p, ancestor_couple_ids ma
#MXS       where p.id = ma.w_id
#MXS )
#MXS select h.name, h.dob, w.name, w.dob
#MXS   from ancestor_couple_ids c, coupled_ancestors h, coupled_ancestors w
#MXS     where c.h_id = h.id and c.w_id= w.id;

explain extended
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
  select a.father, a.mother
    from coupled_ancestors a
      where a.father is not null and a.mother is not null
),
coupled_ancestors (id, name, dob, father, mother)
as
(
  select * 
    from folks 
      where name = 'Me'
  union all
  select p.*
    from folks p, ancestor_couple_ids fa
      where p.id = fa.h_id
  union all
  select p.*
    from folks p, ancestor_couple_ids ma
      where p.id = ma.w_id
)
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
(
  select a.father, a.mother
    from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
  select * 
    from folks 
      where name = 'Me'
  union all
  select p.*
    from folks p, ancestor_couple_ids fa
      where p.id = fa.h_id
  union all
  select p.*
    from folks p, ancestor_couple_ids ma
      where p.id = ma.w_id
)
select *
  from ancestor_couple_ids;


--echo # join of two mutually recursive tables
with recursive
ancestor_couple_ids(h_id, w_id)
as
(
  select a.father, a.mother
    from coupled_ancestors a
),
coupled_ancestors (id, name, dob, father, mother)
as
(
  select * 
    from folks 
      where name = 'Me'
  union all
  select p.*
    from folks p, ancestor_couple_ids fa
      where p.id = fa.h_id
  union all
  select p.*
    from folks p, ancestor_couple_ids ma
      where p.id = ma.w_id
)
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 # execution of prepared query using a recursive table
prepare stmt1 from "
with recursive 
ancestors
as
(
  select *
    from folks
      where name = 'Me' and dob = '2000-01-01'
  union 
  select p.id, p.name, p.dob, p.father, p.mother
    from folks as p, ancestors AS a
      where p.id = a.father or p.id = a.mother
)
select * from ancestors;";

execute stmt1;
execute stmt1;

deallocate prepare stmt1;


--echo # view using a recursive table
create view v1 as
with recursive 
ancestors
as
(
  select *
    from folks
      where name = 'Me' and dob = '2000-01-01'
  union 
  select p.id, p.name, p.dob, p.father, p.mother
    from folks as p, ancestors AS a
      where p.id = a.father or p.id = a.mother
)
select * from ancestors;

show create view v1;

select * from v1;

create view v2 as
with recursive
ancestors
as
(
  select *
    from folks 
      where name = 'Me'
  union 
  select p.*
    from folks as p, ancestors as fa
      where p.id = fa.father
  union
  select p.*
    from folks as p, ancestors as ma
      where p.id = ma.mother
)
select * from ancestors;

show create view v2;

select * from v2;

drop view v1,v2;


explain extended
with recursive 
ancestors
as
(
  select *
    from folks
      where name = 'Me' and dob = '2000-01-01'
  union 
  select p.id, p.name, p.dob, p.father, p.mother
    from folks as p, ancestors AS a
      where p.id = a.father or p.id = a.mother
)
select * from ancestors;


--echo # recursive spec with two anchor selects and two recursive ones 
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
),
ancestors 
as
(
  select p.* from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;


--echo # recursive spec using union all 
with recursive
ancestors
as
(
  select *
    from folks 
      where name = 'Me'
  union all
  select p.*
    from folks as p, ancestors as fa
      where p.id = fa.father
  union all
  select p.*
    from folks as p, ancestors as ma
      where p.id = ma.mother
)
select * from ancestors;


--ERROR ER_NOT_STANDARD_COMPLIANT_RECURSIVE
with recursive
ancestor_ids (id, generation)
as
(
  select father, 1 from folks where name = 'Me' and  father is not null
  union all
  select mother, 1 from folks where name = 'Me' and  mother is not null
  union all
  select father, fa.generation+1 from folks, ancestor_ids fa
    where folks.id = fa.id and (father not in (select id from ancestor_ids))
  union all
  select mother, ma.generation+1 from folks, ancestor_ids ma
    where folks.id = ma.id and (mother not in (select id from ancestor_ids))
)
select generation, name from ancestor_ids a, folks
  where a.id = folks.id;

set standard_compliant_cte=0;

--ERROR ER_WITH_COL_WRONG_LIST
with recursive
ancestor_ids (id, generation)
as
(
  select father from folks where name = 'Me' and  father is not null
  union all
  select mother from folks where name = 'Me' and  mother is not null
  union all
  select father, fa.generation+1 from folks, ancestor_ids fa
    where folks.id = fa.id and (father not in (select id from ancestor_ids))
  union all
  select mother, ma.generation+1 from folks, ancestor_ids ma
    where folks.id = ma.id and (mother not in (select id from ancestor_ids))
)
select generation, name from ancestor_ids a, folks
  where a.id = folks.id;

with recursive
ancestor_ids (id, generation)
as
(
  select father, 1 from folks where name = 'Me' and  father is not null
  union all
  select mother, 1 from folks where name = 'Me' and  mother is not null
  union all
  select father, fa.generation+1 from folks, ancestor_ids fa
    where folks.id = fa.id and father is not null and
          (father not in (select id from ancestor_ids))
  union all
  select mother, ma.generation+1 from folks, ancestor_ids ma
    where folks.id = ma.id and mother is not null and
          (mother not in (select id from ancestor_ids))
)
select generation, name from ancestor_ids a, folks
  where a.id = folks.id;

set standard_compliant_cte=1;

--ERROR ER_NOT_STANDARD_COMPLIANT_RECURSIVE
with recursive
coupled_ancestor_ids (id)
as
(
  select father from folks where name = 'Me' and father is not null
  union 
  select mother from folks where name = 'Me' and mother is not null
  union
  select n.father 
    from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
      where folks.father = fa.id and folks.mother = ma.id and
            (fa.id = n.id or ma.id = n.id) and
            n.father is not null and n.mother is not null 
  union
  select n.mother 
    from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
      where folks.father = fa.id and folks.mother = ma.id and 
            (fa.id = n.id or ma.id = n.id) and 
            n.father is not null and n.mother is not null 
)
select p.* from coupled_ancestor_ids a, folks p
  where a.id = p.id;

#MXS qc_sqlite does not handle "SET STATEMENT ... FOR ..."
#MXS set statement standard_compliant_cte=0 for
with recursive
coupled_ancestor_ids (id)
as
(
  select father from folks where name = 'Me' and father is not null
  union 
  select mother from folks where name = 'Me' and mother is not null
  union
  select n.father 
    from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
      where folks.father = fa.id and folks.mother = ma.id and
            (fa.id = n.id or ma.id = n.id) and
            n.father is not null and n.mother is not null 
  union
  select n.mother 
    from folks, coupled_ancestor_ids fa, coupled_ancestor_ids ma, folks n
      where folks.father = fa.id and folks.mother = ma.id and 
            (fa.id = n.id or ma.id = n.id) and 
            n.father is not null and n.mother is not null 
)
select p.* from coupled_ancestor_ids a, folks p
  where a.id = p.id;

--ERROR ER_NOT_STANDARD_COMPLIANT_RECURSIVE
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks left join ancestor_ids a on folks.id = a.id
  union
  select mother from folks left join ancestor_ids a on folks.id = a.id
),
ancestors 
as
(
  select p.* from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

#MXS qc_sqlite does not handle "SET STATEMENT ... FOR ..."
#MXS set statement standard_compliant_cte=0 for
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks left join ancestor_ids a on folks.id = a.id
  union
  select mother from folks left join ancestor_ids a on folks.id = a.id
),
ancestors 
as
(
  select p.* from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

with recursive
ancestor_ids (id, generation)
as
(
  select father, 1 from folks where name = 'Me'
  union
  select mother, 1 from folks where name = 'Me'
  union
  select father, a.generation+1 from folks, ancestor_ids a
    where folks.id = a.id
  union
  select mother, a.generation+1 from folks, ancestor_ids a
    where folks.id = a.id
),
ancestors 
as
(
  select generation, name from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

--ERROR ER_NOT_STANDARD_COMPLIANT_RECURSIVE
with recursive
ancestor_ids (id, generation)
as
(
  select father, 1 from folks where name = 'Me'
  union
  select mother, 1 from folks where name = 'Me'
  union
  select max(father), max(a.generation)+1 from folks, ancestor_ids a
    where folks.id = a.id
      group by a.generation
  union
  select max(mother), max(a.generation)+1 from folks, ancestor_ids a
    where folks.id = a.id
      group by a.generation
),
ancestors 
as
(
  select generation, name from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

#MXS qc_sqlite does not handle "SET STATEMENT ... FOR ..."
#MXS set statement standard_compliant_cte=0 for
with recursive
ancestor_ids (id, generation)
as
(
  select father, 1 from folks where name = 'Me'
  union
  select mother, 1 from folks where name = 'Me'
  union
  select max(father), a.generation+1 from folks, ancestor_ids a
    where folks.id = a.id
      group by a.generation
  union
  select max(mother), a.generation+1 from folks, ancestor_ids a
    where folks.id = a.id
      group by a.generation
),
ancestors 
as
(
  select generation, name from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

#MXS qc_sqlite does not handle "SET STATEMENT ... FOR ..."
#MXS set statement max_recursive_iterations=1 for
with recursive
ancestor_ids (id, generation)
as
(
  select father, 1 from folks where name = 'Me'
  union
  select mother, 1 from folks where name = 'Me'
  union
  select father, a.generation+1 from folks, ancestor_ids a
    where folks.id = a.id
  union
  select mother, a.generation+1 from folks, ancestor_ids a
    where folks.id = a.id
),
ancestors 
as
(
  select generation, name from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

--echo # query with recursive tables using key access

alter table folks add primary key (id);

explain
with recursive
ancestors
as
(
  select *
    from folks 
      where name = 'Me'
  union 
  select p.*
    from folks as p, ancestors as fa
      where p.id = fa.father
  union
  select p.*
    from folks as p, ancestors as ma
      where p.id = ma.mother
)
select * from ancestors;


with recursive
ancestors
as
(
  select *
    from folks 
      where name = 'Me'
  union 
  select p.*
    from folks as p, ancestors as fa
      where p.id = fa.father
  union
  select p.*
    from folks as p, ancestors as ma
      where p.id = ma.mother
)
select * from ancestors;


--echo #
--echo # EXPLAIN FORMAT=JSON on a query where one recursive CTE uses another:
--echo #
explain 
with recursive 
prev_gen
as
(
  select folks.*
    from folks, prev_gen
      where folks.id=prev_gen.father or folks.id=prev_gen.mother
  union
  select * 
    from folks
      where name='Me'
),
ancestors
as
(
  select *
    from folks
      where name='Me'
  union 
  select *
    from ancestors
  union
    select *
     from prev_gen
)
select ancestors.name, ancestors.dob from ancestors;

explain FORMAT=JSON
with recursive 
prev_gen
as
(
  select folks.*
    from folks, prev_gen
      where folks.id=prev_gen.father or folks.id=prev_gen.mother
  union
  select * 
    from folks
      where name='Me'
),
ancestors
as
(
  select *
    from folks
      where name='Me2'
  union 
  select *
    from ancestors where id < 234
  union
    select *
     from prev_gen where id < 345
)
select ancestors.name, ancestors.dob from ancestors;

--echo #
explain format=json
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 all
  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;


create table my_ancestors
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;

select * from my_ancestors;

delete from my_ancestors;

insert into my_ancestors 
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;

select * from my_ancestors;

drop table my_ancestors;

--echo #
--echo # MDEV-10883: execution of prepared statement from SELECT
--echo #             with recursive CTE that renames columns
--echo #

prepare stmt from"
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;";
execute stmt;
deallocate prepare stmt;

--echo #
--echo # MDEV-10881: execution of prepared statement from
--echo #             CREATE ... SELECT, INSERT ... SELECT       
--echo #

prepare stmt from"
create table my_ancestors
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;";
execute stmt;
deallocate prepare stmt;
select * from my_ancestors;

delete from my_ancestors;

prepare stmt from"
insert into my_ancestors
with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from folks, ancestor_ids a  where folks.id = a.id
  union
  select mother from folks, ancestor_ids a  where folks.id = a.id
)
select p.* from folks as p, ancestor_ids as a where p.id = a.id;";
execute stmt;
deallocate prepare stmt;
select * from my_ancestors;

drop table my_ancestors;

--echo #
--echo # MDEV-10933: WITH clause together with SELECT in parenthesis
--echo #             CREATE SELECT      
--echo #

#MXS qc_sqlite cannot parse this
#MXS qc_parse                 : INF: QC_QUERY_PARSED != QC_QUERY_PARTIALLY_PARSED
#MXS create table my_ancestors
#MXS (
#MXS with recursive
#MXS ancestor_ids (id)
#MXS as
#MXS (
#MXS   select father from folks where name = 'Me'
#MXS   union
#MXS   select mother from folks where name = 'Me'
#MXS   union
#MXS   select father from folks, ancestor_ids a  where folks.id = a.id
#MXS   union
#MXS   select mother from folks, ancestor_ids a  where folks.id = a.id
#MXS )
#MXS select p.* from folks as p, ancestor_ids as a where p.id = a.id
#MXS );
select * from my_ancestors;
drop table my_ancestors;

drop table folks;

--echo #
--echo # MDEV-10372: [bb-10.2-mdev9864 tree] EXPLAIN with recursive CTE enters endless recursion
--echo #
create table t1(a int);
insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
 
explain format=json 
with recursive t as (select a from t1 union select a+10 from t where a < 1000) 
select  * from t;

drop table t1;


--echo #
--echo # MDEV-10737: recursive union with several anchors at the end
--echo #

WITH RECURSIVE cte(n) AS
  ( SELECT n+1 FROM cte WHERE n < 5 UNION SELECT 1 UNION SELECT 1 )
SELECT * FROM cte;

--echo #
--echo # MDEV-10736: recursive definition with anchor over a table with blob
--echo #

CREATE TABLE t1 (f VARCHAR(1024));
WITH RECURSIVE cte(f) AS
  (SELECT t1.f FROM t1 UNION ALL SELECT cte.f FROM cte) 
SELECT * FROM cte as t;
DROP TABLE t1;

--echo #
--echo # MDEV-10899: mergeable derived in the spec of recursive CTE
--echo #

create table t1 (a int);
insert into t1 values
  (0), (1), (2), (3), (4);
create table t2 (a int);
insert into t2 values
  (1), (2), (3), (4), (5);

with recursive
t1 as
(
select x.a from (select a from t2 where t2.a=3) x
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;

explain
with recursive
t1 as
(
select x.a from (select a from t2 where t2.a=3) x
union
select t2.a from t1,t2 where t1.a+1=t2.a
)
select * from t1;

drop table t1,t2;

--echo #
--echo # MDEV-11278: non-mergeable view in the spec of recursive CTE
--echo #

create table t1 (a int);
insert into t1 values
  (0), (1), (2), (3), (4);
create table t2 (a int);
insert into t2 values
  (1), (2), (3), (4), (5);

#MXS qc_mysqlembedded
#MXS qc_get_function_info     : ERR: <(QC_USED_IN_WHERE) != <(QC_USED_IN_WHERE) >(QC_USED_IN_WHERE)
#
#MXS create view v1 as
#MXS   select a from t2 where a < 3
#MXS   union
#MXS   select a from t2 where a > 4; 

with recursive
t1 as
(
select a from v1 where a=1 
union
select v1.a from t1,v1 where t1.a+1=v1.a
)
select * from t1;

drop view v1;
drop table t1,t2;


--echo #
--echo # MDEV-11259: recursive CTE with concatenation operation
--echo #

DROP TABLE IF EXISTS edges;
CREATE TABLE edges(
  a int(10) unsigned NOT NULL,
  b int(10) unsigned NOT NULL,
  PRIMARY KEY (a,b),
  KEY b(b)
);

INSERT INTO edges
  VALUES (1,3),(2,1),(2,4),(3,4),(3,5),(3,6),(4,7),(5,1),(5,6),(6,1);

DROP TABLE IF EXISTS edges2;
CREATE VIEW edges2 (a, b) AS 
 SELECT a, b FROM edges   UNION ALL   SELECT b, a FROM edges;

--sorted_result
WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT a, b, 1 AS distance,
   concat(a, '.', b, '.') AS path_string
  FROM edges
 
  UNION ALL
 
  SELECT tc.a, e.b, tc.distance + 1,
  concat(tc.path_string, e.b, '.') AS path_string
  FROM edges AS e
    JOIN transitive_closure AS tc
      ON e.a = tc.b
  WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT * FROM transitive_closure
ORDER BY a, b, distance;

--sorted_result
WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT a, b, 1 AS distance,
         concat(a, '.', b, '.') AS path_string
  FROM edges
 WHERE a = 1
 
  UNION ALL
 
  SELECT tc.a, e.b, tc.distance + 1,
         concat(tc.path_string, e.b, '.') AS path_string
  FROM edges AS e
  JOIN transitive_closure AS tc ON e.a = tc.b
 WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
  SELECT * FROM transitive_closure
   WHERE b = 6
ORDER BY a, b, distance;

--sorted_result
WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT  a, b, 1 AS distance,
          concat(a, '.', b, '.') AS path_string
  FROM edges2
 
  UNION ALL
 
  SELECT tc.a, e.b, tc.distance + 1,
  concat(tc.path_string, e.b, '.') AS path_string
  FROM edges2 AS e
    JOIN transitive_closure AS tc ON e.a = tc.b
  WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT * FROM transitive_closure
ORDER BY a, b, distance;

--sorted_result
WITH RECURSIVE transitive_closure(a, b, distance, path_string)
AS
( SELECT a, b, 1 AS distance,
         concat(a, '.', b, '.') AS path_string
  FROM edges2
 
  UNION ALL
 
  SELECT tc.a, e.b, tc.distance + 1,
         concat(tc.path_string, e.b, '.') AS path_string
  FROM edges2 AS e
  JOIN transitive_closure AS tc ON e.a = tc.b
 WHERE tc.path_string NOT LIKE concat('%', e.b, '.%')
)
SELECT a, b, min(distance) AS dist FROM transitive_closure
GROUP BY a, b
ORDER BY a, dist, b;

DROP VIEW edges2;
DROP TABLE edges;


--echo #
--echo # MDEV-11674: recursive CTE table that cannot be stored
--echo #             in a heap table
--echo #

create table t1 (id int, test_data varchar(36));

insert into t1(id, test_data)
select id, test_data
    from (
        with recursive data_generator(id, test_data) as (
                select 1 as id, uuid() as test_data
                union all
                select id + 1, uuid() from data_generator where id < 150000
            )
        select * from data_generator
    ) as a;

drop table t1;

--echo #
--echo # MDEV-10773: ANALYZE for query with recursive CTE
--echo #

--source include/analyze-format.inc

#MXS qc_sqlite cannot parse this
#MXS qc_parse                 : INF: QC_QUERY_PARSED != QC_QUERY_INVALID
#MXS analyze format=json 
#MXS with recursive src(counter) as 
#MXS (select 1 
#MXS  union 
#MXS  select counter+1 from src where counter<10
#MXS ) select * from src;

--echo #
--echo # mdev-12360: recursive reference in left operand of LEFT JOIN
--echo #

create table  folks(id int, name char(32), dob date, father int, mother int);

insert into folks values
(100, 'Me', '2000-01-01', 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),
(25, 'Uncle Jim', '1968-11-18', 8, 7),
(98, 'Sister Amy', '2001-06-20', 20, 30),
(7, 'Grandma Sally', '1943-08-23', null, 6),
(8, 'Grandpa Ben', '1940-10-21', null, null),
(6, 'Grandgrandma Martha', '1923-05-17', null, null),
(67, 'Cousin Eddie', '1992-02-28', 25, 27),
(27, 'Auntie Melinda', '1971-03-29', null, null); 

with recursive
ancestor_ids (id)
as
(
  select father from folks where name = 'Me'
  union
  select mother from folks where name = 'Me'
  union
  select father from ancestor_ids as a left join folks on folks.id = a.id
  union
  select mother from ancestor_ids as a left join folks on folks.id = a.id
),
ancestors 
as
(
  select p.* from folks as p, ancestor_ids as a
    where p.id = a.id
)
select * from ancestors;

drop table folks;

--echo #
--echo # mdev-12368: crash with mutually recursive CTE
--echo #             that arenot Standard compliant 
--echo #

create table value_nodes (v char(4));
create table module_nodes(m char(4));
create table module_arguments(m char(4), v char(4));
create table module_results(m char(4), v char(4));

--ERROR ER_NOT_STANDARD_COMPLIANT_RECURSIVE
with recursive
reached_values as 
(
  select v from value_nodes where v in ('v3','v7','v9')
  union
  select module_results.v from module_results, applied_modules
     where module_results.m = applied_modules.m
),
applied_modules as
(
  select module_nodes.m
  from
    module_nodes
    left join
    ( 
      module_arguments
      left join
      reached_values
      on module_arguments.v = reached_values.v
     )
     on reached_values.v is null and
     module_nodes.m = module_arguments.m
  where module_arguments.m is null
)
select * from reached_values;

drop table value_nodes, module_nodes, module_arguments, module_results;

--echo #
--echo # mdev-12375: query using one of two mutually recursive CTEs
--echo #             whose non-recursive part returns an empty set
--echo #

create table value_nodes (v char(4));
insert into value_nodes values
  ('v1'), ('v2'), ('v3'), ('v4'), ('v5'), ('v6'), ('v7'), ('v8'), ('v9'),
  ('v10'), ('v11'), ('v12'), ('v13'), ('v14'), ('v15'), ('v16');
create table module_nodes(m char(4));
insert into module_nodes values
  ('m1'), ('m2'), ('m3'), ('m4'), ('m5'), ('m6'), ('m7');
create table module_arguments(m char(4), v char(4));
insert into module_arguments values
  ('m1','v3'), ('m1','v9'),
  ('m2','v4'), ('m2','v3'), ('m2','v7'),
  ('m3','v6'),
  ('m4','v4'), ('m4','v1'),
  ('m5','v10'), ('m5','v8'), ('m5','v3'),
  ('m6','v8'), ('m6','v1'),
  ('m7','v11'), ('m7','v12');
create table module_results(m char(4), v char(4));
insert into module_results values
  ('m1','v4'),
  ('m2','v1'), ('m2','v6'),
  ('m3','v10'),
  ('m4','v8'),
  ('m5','v11'), ('m5','v9'),
  ('m6','v12'), ('m6','v4'),
  ('m7','v2');

#MXS qc_sqlite does not handle "SET STATEMENT ... FOR ..."
#MXS set statement max_recursive_iterations=2, standard_compliant_cte=0 for
with recursive
reached_values as 
(
  select v from value_nodes where v in ('v3','v7','v9')
  union
  select module_results.v from module_results, applied_modules
     where module_results.m = applied_modules.m
),
applied_modules as
(
  select * from module_nodes where 1=0
  union
  select module_nodes.m
  from
    module_nodes
    left join
    ( 
      module_arguments
      left join
      reached_values
      on module_arguments.v = reached_values.v
     )
     on reached_values.v is null and
     module_nodes.m = module_arguments.m
  where module_arguments.m is null
)
select * from applied_modules;

drop table value_nodes, module_nodes, module_arguments, module_results;

--echo #
--echo # mdev-12519: recursive references in subqueries 
--echo #             

create table t1 (lp char(4) not null, rp char(4) not null);
insert into t1 values
   ('p1','p2'), ('p2','p3'), ('p3','p4'), ('p4','p5'),
   ('p2','p7'), ('p7','p8'), ('p8','p3'), ('p8','p4');

set standard_compliant_cte=0;

with recursive
reachables(p) as 
( 
   select lp from t1 where lp = 'p1'
   union 
   select t1.rp from reachables, t1 
       where t1.lp = reachables.p
)
select * from reachables;

with recursive 
reachables(p) as
(
   select lp from t1 where lp = 'p1'
   union 
   select t1.rp from reachables, t1 
      where 'p3' not in (select * from reachables) and
                 t1.lp = reachables.p
)
select * from reachables;

with recursive 
reachables(p) as
(
   select lp from t1 where lp = 'p1'
   union 
   select t1.rp from reachables, t1 
      where 'p3' not in (select p from reachables where p <= 'p5'
                         union
                         select p from reachables where p > 'p5') and
                 t1.lp = reachables.p
)
select * from reachables;

prepare stmt from "
with recursive 
reachables(p) as
(
   select lp from t1 where lp = 'p1'
   union 
   select t1.rp from reachables, t1 
      where 'p3' not in (select p from reachables where p <= 'p5'
                         union
                         select p from reachables where p > 'p5') and
                 t1.lp = reachables.p
)
select * from reachables;";

execute stmt;
execute stmt;

deallocate prepare stmt;

drop table t1;

create table objects(v char(4) not null);
insert into objects values
  ('v1'), ('v2'), ('v3'), ('v4'), ('v5'),
  ('v6'), ('v7'), ('v8'), ('v9'), ('v10');

create table modules(m char(4) not null);
insert into modules values
  ('m1'), ('m2'), ('m3'), ('m4');

create table module_arguments(m char(4) not null, v char(4) not null);
insert into module_arguments values
  ('m1','v3'), ('m1','v9'),
  ('m2','v4'), ('m2','v7'),
  ('m3','v6'), ('m4','v2');

create table module_results(m char(4) not null, v char(4) not null);
insert into module_results values
  ('m1','v4'),
  ('m2','v1'), ('m2','v6'),
  ('m3','v10'), ('m4','v7');

set standard_compliant_cte=0;

with recursive
reached_objects as 
(
  select v, 'init' as m from objects where v in ('v3','v7','v9')
  union
  select module_results.v, module_results.m from module_results, applied_modules
     where module_results.m = applied_modules.m
),
applied_modules as
(
  select * from modules where 1=0
  union
  select modules.m
  from
    modules
    where
      not exists (select * from module_arguments
                    where module_arguments.m = modules.m and
                          module_arguments.v not in 
                          (select v from reached_objects))
)
select * from reached_objects;

with recursive
reached_objects as 
(
  select v, 'init' as m from objects where v in ('v3','v7','v9')
  union
  select module_results.v, module_results.m from module_results, applied_modules
     where module_results.m = applied_modules.m
),
applied_modules as
(
  select * from modules where 1=0
  union
  select modules.m
  from
    modules
    where 
      'v6' not in (select v from reached_objects) and
      not exists (select * from module_arguments
                    where module_arguments.m = modules.m and
                          module_arguments.v not in 
                          (select v from reached_objects))
)
select * from reached_objects;

prepare stmt from "
with recursive
reached_objects as 
(
  select v, 'init' as m from objects where v in ('v3','v7','v9')
  union
  select module_results.v, module_results.m from module_results, applied_modules
     where module_results.m = applied_modules.m
),
applied_modules as
(
  select * from modules where 1=0
  union
  select modules.m
  from
    modules
    where 
      'v6' not in (select v from reached_objects) and
      not exists (select * from module_arguments
                    where module_arguments.m = modules.m and
                          module_arguments.v not in 
                          (select v from reached_objects))
)
select * from reached_objects;";

execute stmt;
execute stmt;

deallocate prepare stmt;

drop table objects, modules, module_arguments, module_results;

set standard_compliant_cte=default;
select @@standard_compliant_cte;

--echo #
--echo # mdev-12554: impossible where in recursive select 
--echo #             

CREATE TABLE t1 (i int);
INSERT INTO t1 VALUES (1),(2);

WITH RECURSIVE
cte(f) AS ( SELECT i FROM t1 UNION SELECT f FROM t1, cte WHERE 1=0 )
SELECT * FROM cte;

DROP TABLE t1;

--echo #
--echo # mdev-12556: recursive execution uses Aria temporary tables 
--echo #             

CREATE TABLE t (c1 varchar(255), c2 tinytext);
INSERT INTO t VALUES ('a','a'),('b','b'),('c','c'),('d','d');

let $q1=
WITH RECURSIVE cte(f) AS (
  SELECT c1 FROM t
  UNION
  SELECT c1 FROM t, cte
) SELECT COUNT(*) FROM cte;

let $q2=
WITH RECURSIVE cte(f) AS (
  SELECT c2 FROM t
  UNION
  SELECT c2 FROM t, cte
) SELECT COUNT(*) FROM cte;

eval ANALYZE $q1;
eval $q1;

eval ANALYZE $q2;
eval $q2;

DROP TABLE t;

--echo #
--echo # mdev-12563: no recursive references on the top level of the CTE spec 
--echo #  

CREATE TABLE t (i int);
INSERT INTO t VALUES (3), (1),(2);
 
SET standard_compliant_cte=0;
 
WITH RECURSIVE cte(f) AS (
  SELECT i FROM t
  UNION
  SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte )
) SELECT * FROM cte;           

WITH RECURSIVE cte(f) AS (
  SELECT i FROM t
  UNION
  SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte WHERE i < 2 )
  UNION
  SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte WHERE i > 2 )
) SELECT * FROM cte;
           
WITH RECURSIVE cte(f) AS (
  SELECT i FROM t
  UNION
  SELECT i FROM t
    WHERE i NOT IN ( SELECT * FROM cte WHERE i < 2
                     UNION
                     SELECT * FROM cte WHERE i > 2)
) SELECT * FROM cte;           

WITH RECURSIVE cte(f) AS (
  SELECT i FROM t
  UNION
  SELECT i FROM t 
    WHERE i NOT IN ( SELECT * FROM t
                       WHERE i IN ( SELECT * FROM cte ) GROUP BY i )
) SELECT * FROM cte;           

WITH RECURSIVE cte(f) AS (
  SELECT i FROM t
  UNION
  SELECT i FROM t WHERE i NOT IN ( SELECT * FROM cte )
  UNION 
  SELECT * FROM cte WHERE f > 2
) SELECT * FROM cte;           

set standard_compliant_cte=default;

DROP TABLE t;

