php - MySQL : select column values which do not repeat with both possible values 1 and -1 -

i have db table follows

id | branch | allot    1 | comp   | -1    2 |     | -1    3 | comp   | -1     1 | comp   |  1   

where allot=-1 means seat allotted , allot=1 means seat cancelled

i want mysql query return id=2,3 only
not id=1 has cancelled seat later on.

your question says "later on". cannot done data format, because sql tables represent unordered sets. and, have no column specifies ordering.

if want -1 values , exclude 1, there several ways. 1 use not exists:

select t.* dbtable t allot = -1 ,       not exists (select 1                   dbtable t2                   t2.id = t.id , t2.allot = 1                  ); 

if later discover column have ordering records (such createdat), can modify to:

select t.* dbtable t allot = -1 ,       not exists (select 1                   dbtable t2                   t2.id = t.id , t2.allot = 1 ,                         t2.createdat > t.createdat                  );