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#
# check errors
#
WITH RECURSIVE cte AS (
SELECT 1 AS a UNION ALL
SELECT NULL FROM cte WHERE a IS NOT NULL)
CYCLE a, a RESTRICT
SELECT * FROM cte;
ERROR 42S21: Duplicate column name 'a'
WITH RECURSIVE cte AS (
SELECT 1 AS a UNION ALL
SELECT NULL FROM cte WHERE a IS NOT NULL)
CYCLE b RESTRICT
SELECT * FROM cte;
ERROR 42S22: Unknown column 'b' in 'CYCLE clause'
WITH cte AS (
SELECT 1 AS a UNION ALL
SELECT NULL FROM cte WHERE a IS NOT NULL)
CYCLE b RESTRICT
SELECT * FROM cte;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'CYCLE b RESTRICT
SELECT * FROM cte' at line 4
#
# A degenerate case
#
WITH RECURSIVE cte AS (
SELECT 1 AS a, 2 as b)
CYCLE b RESTRICT
SELECT * FROM cte;
a b
1 2
#
# A simple case
#
WITH RECURSIVE cte AS (
SELECT 1 AS a, 2 as b UNION ALL
SELECT 2, 2 FROM cte WHERE a IS NOT NULL)
CYCLE b RESTRICT
SELECT * FROM cte;
a b
1 2
#
# MDEV-20632 case (with fixed syntax)
#
create table t1 (from_ int, to_ int);
insert into t1 values (1,2), (1,100), (2,3), (3,4), (4,1);
WITH RECURSIVE cte (depth, from_, to_) as (
SELECT 0,1,1
UNION
SELECT depth+1, t1.from_, t1.to_
FROM t1, cte WHERE t1.from_ = cte.to_
) CYCLE from_, to_ RESTRICT
select * from cte;
depth from_ to_
0 1 1
1 1 2
1 1 100
2 2 3
3 3 4
4 4 1
create view v1 as WITH RECURSIVE cte (depth, from_, to_) as (
SELECT 0,1,1
UNION
SELECT depth+1, t1.from_, t1.to_
FROM t1, cte WHERE t1.from_ = cte.to_
) CYCLE from_, to_ RESTRICT
select * from cte;
show create view v1;
View Create View character_set_client collation_connection
v1 CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS with recursive cte(`depth`,`from_`,`to_`) as (select 0 AS `depth`,1 AS `from_`,1 AS `to_` union select `cte`.`depth` + 1 AS `depth+1`,`t1`.`from_` AS `from_`,`t1`.`to_` AS `to_` from (`t1` join `cte`) where `t1`.`from_` = `cte`.`to_`) CYCLE `from_`,`to_` RESTRICT select `cte`.`depth` AS `depth`,`cte`.`from_` AS `from_`,`cte`.`to_` AS `to_` from `cte` latin1 latin1_swedish_ci
select * from v1;
depth from_ to_
0 1 1
1 1 2
1 1 100
2 2 3
3 3 4
4 4 1
delete from t1;
insert into t1 values (1,2), (1,NULL), (NULL,NULL), (NULL, 1);
select * from v1;
depth from_ to_
0 1 1
1 1 2
1 1 NULL
drop view v1;
drop table t1;
#
# A simple blob case
#
create table t1 (a int, b text);
insert into t1 values (1, "a");
WITH RECURSIVE cte AS (
SELECT a, b from t1 UNION ALL
SELECT a, b FROM cte WHERE a IS NOT NULL)
CYCLE b RESTRICT
SELECT * FROM cte;
a b
1 a
drop table t1;
#
# check bit types
#
create table t1 (from_ bit(3), to_ bit(3));
insert into t1 values (1,2), (1,7), (2,3), (3,4), (4,1);
WITH RECURSIVE cte (depth, from_, to_) as (
SELECT 0,1,1
UNION
SELECT depth+1, t1.from_, t1.to_
FROM t1, cte WHERE t1.from_ = cte.to_
) CYCLE from_, to_ RESTRICT
select * from cte;
depth from_ to_
0 1 1
1 1 2
1 1 7
2 2 3
3 3 4
4 4 1
drop table t1;
#
# check bit types with BLOBs (TEXT)
#
create table t1 (from_ bit(3), to_ bit(3), load_ text);
insert into t1 values (1,2,"A"), (1,7,"A"), (2,3,"A"), (3,4,"A"), (4,1,"A");
WITH RECURSIVE cte (depth, from_, to_, load_) as (
SELECT 0,1,1,"A"
UNION
SELECT depth+1, t1.from_, t1.to_, t1.load_
FROM t1, cte WHERE t1.from_ = cte.to_
) CYCLE from_, to_, load_ RESTRICT
select * from cte;
depth from_ to_ load_
0 1 1 A
1 1 2 A
1 1 7 A
2 2 3 A
3 3 4 A
4 4 1 A
insert into t1 values (4,1,"B");
WITH RECURSIVE cte (depth, from_, to_, load_) as (
SELECT 0,1,1,"A"
UNION
SELECT depth+1, t1.from_, t1.to_, t1.load_
FROM t1, cte WHERE t1.from_ = cte.to_
) CYCLE from_, to_, load_ RESTRICT
select * from cte;
depth from_ to_ load_
0 1 1 A
1 1 2 A
1 1 7 A
2 2 3 A
3 3 4 A
4 4 1 A
4 4 1 B
drop table t1;
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