摘要:
mysql-innerJoin访问多表-优化器改变表访问顺序-分析
DDL准备:
表结构:
create table t1 (a int, b int) engine=innodb;
create table t2 (a int, b int) engine=innodb;
create table t3 (a int, b int) engine=innodb;
create table t4 (a int, b int) engine=innodb;
create table t5 (a int, b int) engine=innodb;
插入数据:
insert into t1 values (1, 3), (2, 3), (3, 4);
insert into t2 values (1, 2), (2, 4), (4, 5);
insert into t3 values (1, 2), (2, 3), (3, 4), (4, 5);
insert into t4 values (1, 3);
insert into t5 values (1, 2), (3, 4);
inner join查询:
SELECT
*
FROM