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join_nested.test, join_nested.result:

Browse Source 
new file
Many files:
  Nested joins added.


sql/item_cmpfunc.h:
  Nested joins added.
sql/item_func.h:
  Nested joins added.
sql/sql_base.cc:
  Nested joins added.
sql/sql_lex.cc:
  Nested joins added.
sql/sql_lex.h:
  Nested joins added.
sql/sql_parse.cc:
  Nested joins added.
sql/sql_select.cc:
  Nested joins added.
sql/sql_select.h:
  Nested joins added.
sql/sql_yacc.yy:
  Nested joins added.
sql/table.h:
  Nested joins added.
mysql-test/r/join_outer.result:
  Nested joins added.
mysql-test/r/select.result:
  Nested joins added.
This commit is contained in:
unknown
2004-06-10 22:27:21 -07:00
parent d4898d174c
commit cd23d6e37a
14 changed files with 3148 additions and 239 deletions
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693
mysql-test/t/join_nested.test Normal file
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@@ -0,0 +1,693 @@
DROP TABLE IF EXISTS t0,t1,t2,t3,t4,t5,t6,t7,t8,t9;
CREATE TABLE t0 (a int, b int, c int);
CREATE TABLE t1 (a int, b int, c int);
CREATE TABLE t2 (a int, b int, c int);
CREATE TABLE t3 (a int, b int, c int);
CREATE TABLE t4 (a int, b int, c int);
CREATE TABLE t5 (a int, b int, c int);
CREATE TABLE t6 (a int, b int, c int);
CREATE TABLE t7 (a int, b int, c int);
CREATE TABLE t8 (a int, b int, c int);
CREATE TABLE t9 (a int, b int, c int);
INSERT INTO t0 VALUES (1,1,0), (1,2,0), (2,2,0);
INSERT INTO t1 VALUES (1,3,0), (2,2,0), (3,2,0);
INSERT INTO t2 VALUES (3,3,0), (4,2,0), (5,3,0);
INSERT INTO t3 VALUES (1,2,0), (2,2,0);
INSERT INTO t4 VALUES (3,2,0), (4,2,0);
INSERT INTO t5 VALUES (3,1,0), (2,2,0), (3,3,0);
INSERT INTO t6 VALUES (3,2,0), (6,2,0), (6,1,0);
INSERT INTO t7 VALUES (1,1,0), (2,2,0);
INSERT INTO t8 VALUES (0,2,0), (1,2,0);
INSERT INTO t9 VALUES (1,1,0), (1,2,0), (3,3,0);
SELECT t2.a,t2.b
FROM t2;
SELECT t3.a,t3.b
FROM t3;
SELECT t4.a,t4.b
FROM t4;
SELECT t3.a,t3.b,t4.a,t4.b
FROM t3,t4;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t2.b=t4.b;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t3.a=1 AND t2.b=t4.b;
EXPLAIN
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t2.b=t4.b
WHERE t3.a=1 OR t3.c IS NULL;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t2.b=t4.b
WHERE t3.a=1 OR t3.c IS NULL;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t2.b=t4.b
WHERE t3.a>1 OR t3.c IS NULL;
SELECT t5.a,t5.b
FROM t5;
SELECT t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t3,t4,t5;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN
(t3, t4, t5)
ON t2.b=t4.b;
EXPLAIN
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN
(t3, t4, t5)
ON t2.b=t4.b
WHERE t3.a>1 OR t3.c IS NULL;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN
(t3, t4, t5)
ON t2.b=t4.b
WHERE t3.a>1 OR t3.c IS NULL;
EXPLAIN
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN
(t3, t4, t5)
ON t2.b=t4.b
WHERE (t3.a>1 OR t3.c IS NULL) AND
(t5.a<3 OR t5.c IS NULL);
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,t5.a,t5.b
FROM t2
LEFT JOIN
(t3, t4, t5)
ON t2.b=t4.b
WHERE (t3.a>1 OR t3.c IS NULL) AND
(t5.a<3 OR t5.c IS NULL);
SELECT t6.a,t6.b
FROM t6;
SELECT t7.a,t7.b
FROM t7;
SELECT t6.a,t6.b,t7.a,t7.b
FROM t6,t7;
SELECT t8.a,t8.b
FROM t8;
EXPLAIN
SELECT t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t6,
t7
LEFT JOIN
t8
ON t7.b=t8.b AND t6.b < 10;
SELECT t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM t6,
t7
LEFT JOIN
t8
ON t7.b=t8.b AND t6.b < 10;
SELECT t5.a,t5.b
FROM t5;
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM 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;
SELECT t5.a,t5.b,t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
FROM 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 AND
(t8.a < 1 OR t8.c IS NULL);
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t3.a=1 AND t2.b=t4.b;
SELECT 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 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;
SELECT 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 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
WHERE t2.a > 3 AND
(t6.a < 6 OR t6.c IS NULL);
SELECT t1.a,t1.b
FROM t1;
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);
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);
SELECT t0.a,t0.b
FROM t0;
EXPLAIN
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);
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);
EXPLAIN
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);
SELECT t9.a,t9.b
FROM t9;
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);
SELECT t1.a,t1.b
FROM t1;
SELECT t2.a,t2.b
FROM t2;
SELECT t3.a,t3.b
FROM t3;
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2
LEFT JOIN
t3
ON t2.b=t3.b;
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;
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b
FROM t1, t3
RIGHT JOIN
t2
ON t2.b=t3.b
WHERE t1.a <= 2;
SELECT t3.a,t3.b,t4.a,t4.b
FROM t3,t4;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t2
LEFT JOIN
(t3, t4)
ON t3.a=1 AND t2.b=t4.b;
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, t2
LEFT JOIN
(t3, t4)
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, (t3, t4)
RIGHT JOIN
t2
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
SELECT t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t1, t3, t4
RIGHT JOIN
t2
ON t3.a=1 AND t2.b=t4.b
WHERE t1.a <= 2;
CREATE INDEX idx_b ON t2(b);
EXPLAIN
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t3,t4
LEFT JOIN
(t1,t2)
ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b;
SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
FROM t3,t4
LEFT JOIN
(t1,t2)
ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b;
EXPLAIN
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);
CREATE INDEX idx_b ON t4(b);
CREATE INDEX idx_b ON t5(b);
EXPLAIN
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);
CREATE INDEX idx_b ON t8(b);
EXPLAIN
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);
CREATE INDEX idx_b ON t1(b);
CREATE INDEX idx_a ON t0(a);
EXPLAIN
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);
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);
SELECT t2.a,t2.b
FROM t2;
SELECT t3.a,t3.b
FROM t3;
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2 LEFT JOIN t3 ON t2.b=t3.b
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a IS NULL);
SELECT t2.a,t2.b,t3.a,t3.b
FROM t2 LEFT JOIN (t3) ON t2.b=t3.b
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a IS NULL);
ALTER TABLE t3
CHANGE COLUMN a a1 int,
CHANGE COLUMN c c1 int;
SELECT t2.a,t2.b,t3.a1,t3.b
FROM t2 LEFT JOIN t3 ON t2.b=t3.b
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a1 IS NULL);
SELECT t2.a,t2.b,t3.a1,t3.b
FROM t2 NATURAL LEFT JOIN t3
WHERE t2.a = 4 OR (t2.a > 4 AND t3.a1 IS NULL);
DROP TABLE t0,t1,t2,t3,t4,t5,t6,t7,t8,t9;