MySQL trigger before Insert value Checking

Question

I have a table staff with office column. Currently the office column do not accept NULL values. The application persisting onto this t

Answer 1

First, alter the table to allow NULLs:

ALTER TABLE Staff MODIFY office CHAR(40) DEFAULT "N/A";

(Change CHAR(40) to whatever is appropriate.) Then you could use as your trigger:

CREATE TRIGGER staffOfficeNullReplacerTrigger 
BEFORE INSERT 
ON Staff
  FOR EACH ROW BEGIN
    IF (NEW.office IS NULL) THEN
      SET NEW.office = "N/A";
    END IF