create table testA(
  Id number(10) primary key,
  Name varchar(10)
);
insert into testA values(1, '小黄');
insert into testA values(2, '小绿'); 
insert into testA values(3, '小白');
insert into testA values(4, '小黑');
insert into testA values(5, '小花');
commit;

create table testB(
  Id number(10) primary key, 
  age number(10)
);
insert into testB values(1, 10);
insert into testB values(2, 11);
insert into testB values(3, 12);
insert into testB values(4, 13);
commit;

1、join on后面加and

select *
from testA a
  left join testB b on a.id = b.id
  and b.age = 10

 

2、where后面加on

select *
from testA a
  left join testB b on a.id = b.id
where 1=1 
and b.age = 10