mysql-为什么第一次查询结果为空，但第二次查询有数据

select * from
(select 
 t1.company_name, 
 t1.acceptance_date, 
 t1.project id, 
 rank 
from 
table1 t1 
left join 
(SELECT 
id， 
company_name, 
acceptance_date, 
project_id, 
ct, 
if( @p=a.company_name,@r :=@r +a.ct，@r:=a.ct) as rank, 
@p:=a.company_name from 
(SELECT 
id, 
company_name, 
acceptance_date, 
project id, 
1 AS ct 
FROM table1 
WHERE company_name is not null 
AND IS_DELETED = 0 
order by company_name, acceptance_date 
)as a
)t2 
on t1.id=t2.id)c 
HAVING rank=2



 CREATE TABLE table1(
   id INT,
   project_id INT,
   company_name VARCHAR(100) NOT NULL,
   acceptance_date DATE,
   is_deleted INT
   PRIMARY KEY (id )
    )ENGINE=InnoDB DEFAULT CHARSET=utf8;

insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (1,1, "company1","2020/12/31",0);
insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (2,2,  "company1","2021/12/31",0);
insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (3,3,  "company1","2022/12/31",0);
insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (4,4, "company2","2021/1/1",0);
insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (5,5, "company3","2020/2/3",0);
insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (6,6, "company4","2020/12/3",0);
insert into table1(id,project_id,company_name,acceptance_date,is_deleted) value (7,7, "company5","2020/10/3",0);