Time field comparison time size in MySQL

You want to query a time field that is greater than 0 A point is less than the time between two points and more than the time after two points
select a.sqr ' Applicant ',h.lastname,a.sqrq ' Application date ',b.jbrq as ' Start date ',b.jsrq as ' End date ',
b.sjkssj as ' Actual start time ',b.sjjssj as ' The actual end time ',b.sjsc as ' Overtime hours ',
case b.sjjssj
when b.sjjssj >='00:00:00' and b.sjjssj <'02:00:00' then 50
when b.sjjssj >'02:00:00' then 80
end ' Overtime allowance '
from formtable_main_52 a
left join formtable_main_52_dt1 b on a.id = b.mainid
left join hrmresource h on h.id=a.sqr
left join workflow_requestbase w on a.requestid=w.requestid
where b.jsrq>b.jbrq and w.currentnodetype=3
But the result of the query ：
287 Dai Xujun 2022-03-24 2022-03-15 2022-03-16 17:30 00:06 6 80
287 Dai Xujun 2022-03-24 2022-03-18 2022-03-19 17:31 00:30 6.5 80
284 Sun Hongwei 2022-03-24 2022-03-18 2022-03-19 17:07 00:38 7 80
284 Sun Hongwei 2022-03-24 2022-03-15 2022-03-16 17:30 00:06 6 80
285 Li Cailing 2022-03-24 2022-03-15 2022-03-16 17:30 00:06 6 80
285 Li Cailing 2022-03-24 2022-03-18 2022-03-19 17:38 00:40 6.5 80
260 Bian Youpeng 2022-04-02 2022-04-01 2022-04-02 17:00 02:30 9
41 Li Xiaowen 2022-04-02 2022-04-01 2022-04-02 17:20 03:00 9
315 Zhangyunfang 2022-04-02 2022-04-01 2022-04-02 17:00 03:00 9.5
303 Yu anyin 2022-04-02 2022-04-01 2022-04-02 17:00 03:00 9.5
Time comparison cannot be used > ,< This way of comparison , I tried in where Write directly after the condition b.sjjssj>'02:00' The result is correct ,
But in case when above then The result is wrong , What's the situation depressed