pro1
INSERT INTO join_table_1 VALUES (4, '16a'); Select * from join_table_1 inner join join_table_2 on join_table_1.name<join_table_2.age and join_table_1.id=join_table_2.id; + failed to receive response from observer. reason=Failed to receive from server. poll return POLLHUP=16 or POLLERR=str(event & select.POLLERR) failed to receive response from observer. reason=Failed to receive from server. poll return POLLHUP=16 or POLLERR=str(event & select.POLLERR)
就是对于表达式当中的比较类型，如果不一致的话，一开始是没考虑，后面是直接返回类型不一致的报错，但是没过，看别人的思路，应该就是要进行强转比较
就是当类型不可比的时候，如何处理？
char为什么能转换成double?是否能转为Int或其它类型?
subpro1
这个就是在.h文件中，就不用再声明类名前缀了
将Value::去掉即可
subpro2
就是运行以下make clean，清理一下缓存
subpro3
这个很抽象的一点是代码内部自己定义了一个string,和std::string不一样（？
但确实不太理解之间的区别
用.c_str()就能正常打印和输出了
test
大数据
select * from join_table_large_1
inner join join_table_large_2 on join_table_large_1.id=join_table_large_2.id
inner join join_table_large_3 on join_table_large_1.id=join_table_large_3.id
inner join join_table_large_4 on join_table_large_3.id=join_table_large_4.id
inner join join_table_large_5 on 1=1
inner join join_table_large_6 on join_table_large_5.id=join_table_large_6.id
where
join_table_large_3.num3 <10
and
join_table_large_5.num5>90;
select * from join_table_large_1 inner join join_table_large_2 on join_table_large_1.id=join_table_large_2.id inner join join_table_large_3 on join_table_large_1.id=join_table_large_3.id inner join join_table_large_4 on join_table_large_3.id=join_table_large_4.id inner join join_table_large_5 on 1=1 inner join join_table_large_6 on join_table_large_5.id=join_table_large_6.id where join_table_large_3.num3 <10 and join_table_large_5.num5>90;
select * from join_table_1 inner join join_table_2 on 1=1
select * from join_table_large_5
CREATE TABLE join_table_1(id int, name char);
INSERT INTO join_table_1 VALUES (1, 'a');
INSERT INTO join_table_1 VALUES (2, 'b');
CREATE TABLE join_table_2(id int, num int);
INSERT INTO join_table_2 VALUES (1, 2);
INSERT INTO join_table_2 VALUES (2, 15);
create table join_table_large_1(id int, num1 int);
create table join_table_large_2(id int, num2 int);
create table join_table_large_3(id int, num3 int);
create table join_table_large_4(id int, num4 int);
create table join_table_large_5(id int, num5 int);
create table join_table_large_6(id int, num6 int);
insert into join_table_large_1 values(1, 1);
insert into join_table_large_1 values(2, 2);
insert into join_table_large_1 values(3, 3);
insert into join_table_large_1 values(4, 4);
insert into join_table_large_1 values(5, 5);
insert into join_table_large_1 values(6, 6);
insert into join_table_large_1 values(7, 7);
insert into join_table_large_1 values(8, 8);
insert into join_table_large_1 values(9, 9);
insert into join_table_large_1 values(10, 10);
insert into join_table_large_1 values(11, 11);
insert into join_table_large_1 values(12, 12);
insert into join_table_large_2 values(1, 1);
insert into join_table_large_2 values(2, 2);
insert into join_table_large_2 values(3, 3);
insert into join_table_large_2 values(4, 4);
insert into join_table_large_2 values(5, 5);
insert into join_table_large_2 values(6, 6);
insert into join_table_large_2 values(7, 7);
insert into join_table_large_2 values(8, 8);
insert into join_table_large_2 values(9, 9);
insert into join_table_large_2 values(10, 10);
insert into join_table_large_2 values(11, 11);
insert into join_table_large_2 values(12, 12);
insert into join_table_large_3 values(1, 1);
insert into join_table_large_3 values(2, 2);
insert into join_table_large_3 values(3, 3);
insert into join_table_large_3 values(4, 4);
insert into join_table_large_3 values(5, 5);
insert into join_table_large_3 values(6, 6);
insert into join_table_large_3 values(7, 7);
insert into join_table_large_3 values(8, 8);
insert into join_table_large_3 values(9, 9);
insert into join_table_large_3 values(10, 10);
insert into join_table_large_3 values(11, 11);
insert into join_table_large_3 values(12, 12);
insert into join_table_large_4 values(1, 1);
insert into join_table_large_4 values(2, 2);
insert into join_table_large_4 values(3, 3);
insert into join_table_large_4 values(4, 4);
insert into join_table_large_4 values(5, 5);
insert into join_table_large_4 values(6, 6);
insert into join_table_large_4 values(7, 7);
insert into join_table_large_4 values(8, 8);
insert into join_table_large_4 values(9, 9);
insert into join_table_large_4 values(10, 10);
insert into join_table_large_4 values(11, 11);
insert into join_table_large_4 values(12, 12);
insert into join_table_large_5 values(87, 87);
insert into join_table_large_5 values(88, 88);
insert into join_table_large_5 values(89, 89);
insert into join_table_large_5 values(90, 90);
insert into join_table_large_5 values(91, 91);
insert into join_table_large_5 values(92, 92);
insert into join_table_large_5 values(93, 93);
insert into join_table_large_5 values(94, 94);
insert into join_table_large_5 values(95, 95);
insert into join_table_large_5 values(96, 96);
insert into join_table_large_5 values(97, 97);
insert into join_table_large_5 values(98, 98);
insert into join_table_large_5 values(99, 99);
insert into join_table_large_5 values(100, 100);
insert into join_table_large_6 values(86, 86);
insert into join_table_large_6 values(87, 87);
insert into join_table_large_6 values(88, 88);
insert into join_table_large_6 values(89, 89);
insert into join_table_large_6 values(90, 90);
insert into join_table_large_6 values(91, 91);
insert into join_table_large_6 values(92, 92);
insert into join_table_large_6 values(93, 93);
insert into join_table_large_6 values(94, 94);
insert into join_table_large_6 values(95, 95);
insert into join_table_large_6 values(96, 96);
insert into join_table_large_6 values(97, 97);
insert into join_table_large_6 values(98, 98);
insert into join_table_large_6 values(99, 99);
insert into join_table_large_6 values(100, 100);
大数据下没问题，就是数据要求可判断的
miniob > select * from join_table_large_1 inner join join_table_large_2 on join_table_large_1.id=join_table_large_2.id inner join join_table_large_3 on join_table_large_1.id=join_table_large_3.id inner join join_table_large_4 on join_table_large_3.id=join_table_large_4.id inner join join_table_large_5 on 1=1 inner join join_table_large_6 on join_table_large_5.id=join_table_large_6.id where join_table_large_3.num3 <10 and join_table_large_5.num5>90;
id | num1 | id | num6 | id | num5 | id | num4 | id | num3 | id | num2
1 | 1 | 91 | 91 | 91 | 91 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 92 | 92 | 92 | 92 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 93 | 93 | 93 | 93 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 94 | 94 | 94 | 94 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 95 | 95 | 95 | 95 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 96 | 96 | 96 | 96 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 97 | 97 | 97 | 97 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 98 | 98 | 98 | 98 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 99 | 99 | 99 | 99 | 1 | 1 | 1 | 1 | 1 | 1
1 | 1 | 100 | 100 | 100 | 100 | 1 | 1 | 1 | 1 | 1 | 1
2 | 2 | 91 | 91 | 91 | 91 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 92 | 92 | 92 | 92 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 93 | 93 | 93 | 93 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 94 | 94 | 94 | 94 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 95 | 95 | 95 | 95 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 96 | 96 | 96 | 96 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 97 | 97 | 97 | 97 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 98 | 98 | 98 | 98 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 99 | 99 | 99 | 99 | 2 | 2 | 2 | 2 | 2 | 2
2 | 2 | 100 | 100 | 100 | 100 | 2 | 2 | 2 | 2 | 2 | 2
3 | 3 | 91 | 91 | 91 | 91 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 92 | 92 | 92 | 92 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 93 | 93 | 93 | 93 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 94 | 94 | 94 | 94 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 95 | 95 | 95 | 95 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 96 | 96 | 96 | 96 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 97 | 97 | 97 | 97 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 98 | 98 | 98 | 98 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 99 | 99 | 99 | 99 | 3 | 3 | 3 | 3 | 3 | 3
3 | 3 | 100 | 100 | 100 | 100 | 3 | 3 | 3 | 3 | 3 | 3
4 | 4 | 91 | 91 | 91 | 91 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 92 | 92 | 92 | 92 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 93 | 93 | 93 | 93 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 94 | 94 | 94 | 94 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 95 | 95 | 95 | 95 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 96 | 96 | 96 | 96 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 97 | 97 | 97 | 97 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 98 | 98 | 98 | 98 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 99 | 99 | 99 | 99 | 4 | 4 | 4 | 4 | 4 | 4
4 | 4 | 100 | 100 | 100 | 100 | 4 | 4 | 4 | 4 | 4 | 4
5 | 5 | 91 | 91 | 91 | 91 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 92 | 92 | 92 | 92 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 93 | 93 | 93 | 93 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 94 | 94 | 94 | 94 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 95 | 95 | 95 | 95 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 96 | 96 | 96 | 96 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 97 | 97 | 97 | 97 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 98 | 98 | 98 | 98 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 99 | 99 | 99 | 99 | 5 | 5 | 5 | 5 | 5 | 5
5 | 5 | 100 | 100 | 100 | 100 | 5 | 5 | 5 | 5 | 5 | 5
6 | 6 | 91 | 91 | 91 | 91 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 92 | 92 | 92 | 92 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 93 | 93 | 93 | 93 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 94 | 94 | 94 | 94 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 95 | 95 | 95 | 95 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 96 | 96 | 96 | 96 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 97 | 97 | 97 | 97 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 98 | 98 | 98 | 98 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 99 | 99 | 99 | 99 | 6 | 6 | 6 | 6 | 6 | 6
6 | 6 | 100 | 100 | 100 | 100 | 6 | 6 | 6 | 6 | 6 | 6
7 | 7 | 91 | 91 | 91 | 91 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 92 | 92 | 92 | 92 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 93 | 93 | 93 | 93 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 94 | 94 | 94 | 94 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 95 | 95 | 95 | 95 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 96 | 96 | 96 | 96 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 97 | 97 | 97 | 97 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 98 | 98 | 98 | 98 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 99 | 99 | 99 | 99 | 7 | 7 | 7 | 7 | 7 | 7
7 | 7 | 100 | 100 | 100 | 100 | 7 | 7 | 7 | 7 | 7 | 7
8 | 8 | 91 | 91 | 91 | 91 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 92 | 92 | 92 | 92 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 93 | 93 | 93 | 93 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 94 | 94 | 94 | 94 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 95 | 95 | 95 | 95 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 96 | 96 | 96 | 96 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 97 | 97 | 97 | 97 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 98 | 98 | 98 | 98 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 99 | 99 | 99 | 99 | 8 | 8 | 8 | 8 | 8 | 8
8 | 8 | 100 | 100 | 100 | 100 | 8 | 8 | 8 | 8 | 8 | 8
9 | 9 | 91 | 91 | 91 | 91 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 92 | 92 | 92 | 92 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 93 | 93 | 93 | 93 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 94 | 94 | 94 | 94 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 95 | 95 | 95 | 95 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 96 | 96 | 96 | 96 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 97 | 97 | 97 | 97 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 98 | 98 | 98 | 98 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 99 | 99 | 99 | 99 | 9 | 9 | 9 | 9 | 9 | 9
9 | 9 | 100 | 100 | 100 | 100 | 9 | 9 | 9 | 9 | 9 | 9
类型检测
CREATE TABLE join_table_1(id int, name char);
CREATE TABLE join_table_2(id int, num int);
INSERT INTO join_table_1 VALUES (1, 'a');
INSERT INTO join_table_1 VALUES (2, 'b');
INSERT INTO join_table_1 VALUES (3, 'c');
INSERT INTO join_table_2 VALUES (1, 2);
INSERT INTO join_table_2 VALUES (2, 15);
select * from join_table_1 inner join join_table_2 on join_table_1.name<join_table_2.num and join_table_1.id=join_table_2.id
select * from join_table_1
select * from join_table_1 inner join join_table_2 on join_table_1.id=join_table_2.id
select * from join_table_1 inner join join_table_2 on join_table_1.id=join_table_2.id
select * from join_table_1 inner join join_table_2 on join_table_1.id=join_table_2.id