join_nested.result

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

a	b
1	3
2	2
3	2
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	3	3	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	3	3	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	3	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	3	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	3	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	3	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	3	3	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL
3	2	3	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	2	3	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	2	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	2	3	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	2	3	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	1	2
3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	1	2
3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2)
WHERE (t2.a >= 4 OR t2.c IS NULL);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	3	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
1	3	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	3	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	3	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	3	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	3	2	2	2	6	2	2	2	1	2
3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
3	2	4	2	1	2	4	2	2	2	3	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	3	2	2	2	1	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2
3	2	4	2	1	2	4	2	2	2	6	2	2	2	1	2
3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
SELECT t0.a,t0.b
FROM t0;
a	b
1	1
1	2
2	2
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2)
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	
1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	
1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t3`.`a` = 1))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) where ((`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t0`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)))
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2)
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL
1	2	3	2	4	2	1	2	3	2	3	1	3	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	3	2	2	2	3	2	2	2	0	2
1	2	3	2	4	2	1	2	3	2	2	2	3	2	2	2	1	2
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	1	2
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	2	3	2	4	2	1	2	4	2	3	1	3	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL
1	2	3	2	4	2	1	2	4	2	2	2	3	2	2	2	0	2
1	2	3	2	4	2	1	2	4	2	2	2	3	2	2	2	1	2
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	1	2
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	3	2	1	1	NULL	NULL
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	0	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	3	2	2	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL
EXPLAIN EXTENDED
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	Using where
1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	Using where
1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	Using where
1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	Using where
1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	Using where
1	SIMPLE	t9	ALL	NULL	NULL	NULL	NULL	3	Using where
Warnings:
Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b`,`test`.`t9`.`a` AS `a`,`test`.`t9`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t3`.`a` = 1))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) join `test`.`t9` where ((`test`.`t9`.`a` = 1) and (`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t0`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)) and ((`test`.`t3`.`a` < 5) or isnull(`test`.`t3`.`c`)) and ((`test`.`t4`.`b` = `test`.`t3`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t4`.`c`)) and ((`test`.`t5`.`a` >= 2) or isnull(`test`.`t5`.`c`)) and ((`test`.`t6`.`a` >= 4) or isnull(`test`.`t6`.`c`)) and ((`test`.`t7`.`a` <= 2) or isnull(`test`.`t7`.`c`)) and ((`test`.`t8`.`a` < 1) or isnull(`test`.`t8`.`c`)) and ((`test`.`t9`.`b` = `test`.`t8`.`b`) or isnull(`test`.`t8`.`c`)))
SELECT t9.a,t9.b
FROM t9;
a	b
1	1
1	2
3	3
SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b,t9.a,t9.b
FROM t0,t1
LEFT JOIN                
( 
t2
LEFT JOIN              
(t3, t4)
ON t3.a=1 AND t2.b=t4.b,
t5 
LEFT JOIN 
( 
(t6, t7)
LEFT JOIN 
t8
ON t7.b=t8.b AND t6.b < 10
)
ON t6.b >= 2 AND t5.b=t7.b 
)
ON (t3.b=2 OR t3.c IS NULL) AND (t6.b=2 OR t6.c IS NULL) AND
(t1.b=t5.b OR t3.c IS NULL OR t6.c IS NULL or t8.c IS NULL) AND
(t1.a != 2),
t9
WHERE t0.a=1 AND
t0.b=t1.b AND          
(t2.a >= 4 OR t2.c IS NULL) AND
(t3.a < 5 OR t3.c IS NULL) AND
(t3.b=t4.b OR t3.c IS NULL OR t4.c IS NULL) AND
(t5.a >=2 OR t5.c IS NULL) AND
(t6.a >=4 OR t6.c IS NULL) AND
(t7.a <= 2 OR t7.c IS NULL) AND
(t8.a < 1 OR t8.c IS NULL) AND
(t8.b=t9.b OR t8.c IS NULL) AND
(t9.a=1);
a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b	a	b
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL	1	1
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	1
1	2	2	2	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	4	2	1	2	3	2	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	4	2	1	2	3	2	2	2	6	2	2	2	0	2	1	2
1	2	3	2	4	2	1	2	3	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	4	2	1	2	4	2	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	4	2	1	2	4	2	2	2	6	2	2	2	0	2	1	2
1	2	3	2	4	2	1	2	4	2	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	1	6	2	1	1	NULL	NULL	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	2	2	6	2	2	2	0	2	1	2
1	2	3	2	5	3	NULL	NULL	NULL	NULL	3	3	NULL	NULL	NULL	NULL	NULL	NULL	1	2
SELECT t1.a,t1.b
FROM t1;
a	b
1	3
2	2
3	2
SELECT t2.a,t2.b
FROM t2;
a	b
3	3
4	2
5	3
SELECT t3.a,t3.b
FROM t3;
a	b
1	2
2	2
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2 
LEFT JOIN              
t3
ON t2.b=t3.b;
a	b	a	b
3	3	NULL	NULL
4	2	1	2
4	2	2	2
5	3	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b
FROM t1, t2 
LEFT JOIN              
t3
ON t2.b=t3.b
WHERE t1.a <= 2;
a	b	a	b	a	b
1	3	3	3	NULL	NULL
2	2	3	3	NULL	NULL
1	3	4	2	1	2
1	3	4	2	2	2
2	2	4	2	1	2
2	2	4	2	2	2
1	3	5	3	NULL	NULL
2	2	5	3	NULL	NULL
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b
FROM t1, t3