Question

Is possible prevent the insertion in a mysql table after some date and time?

for example i have 2 tables:

TABLE exams 
(
...
examID int primary key auto_increment,
examDate DATE,
examTime TIME, 
...
)


TABLE inscripts
(
...
examID int not null references exams(examID),
insDate DATE,
insTime TIME,
...
)

i want to prevent the insertion of new inscriptions when the exam is playing.

There are some function to prevent this or check easily if current date and current time are equal or bigger than the date and time in matches table?

Answer 1

You could create a trigger that validates the insert before proceeding. Pseudo-code, but something like:

DELIMITER |
CREATE TRIGGER `Stop_Insert_During_Exam`
BEFORE UPDATE ON `inscripts`
FOR EACH ROW
BEGIN
  DECLARE msg VARCHAR(255);
  -- Check
  -- Test if an exam is going on. If so:
  SET msg = "You cannot add an inscription while an exam is going on.';
  SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = msg;
  -- /Check
END;
|