i have team member table and team table.
In team member table have , three columns are there teamid, staff_id and stafftype(leader or technician). Only one leader (staff_type column value) will comes in one team. So when i insert data to team member table i need to check whether any leader is there in same team.
How to show an error message that “already have leader in this team”?
team_id staff_id stafftype
1 2 leader
2 1 other
3 8 other
1 5 Technician
2 3 Other
1 4 Leader //This should not come. becoz already teamid-1 have Leader When trying to save from frond end, need to show error message ie;"already have leader in this team"