- On initialization places a zero in that column, on future updates puts the current value of the timestamp in.
- A default value is used on initialization, a current timestamp is inserted on update of the row.
- CHAR(3), since MySQL automatically adjusted the data type.
ALTER TABLE techpreparation_questions ENGINE innodb;
- VARCHARs with length less than 4 become CHARs
- CHARs with length more than 3 become VARCHARs.
- NOT NULL gets added to the columns declared as PRIMARY KEYs
- Default values such as NULL are specified for each column