The use of the MySQL Date_add () function

Date_add (Date,interval expr type)

Types (Type)	Expr parameter format	Description
Microsecond	Numeric type	With subtlety as the unit of calculation
SECOND	Numeric type	The unit of measure in seconds
MINUTE	Numeric type	Counting units in minutes
HOUR	Numeric type	The unit of calculation in hours
Day	Numeric type	In days as the unit of calculation
WEEK	Numeric type	Week as the unit of calculation
MONTH	Numeric type	Month as the unit of calculation
QUARTER	Numeric type	Quarter as the unit of calculation
Year	Numeric type	Year as the unit of calculation
Second_microsecond	String type, formatted as ' Second-microsecond or Second.microsecond or Second/microsecond '
Minute_microsecond	String type, formatted as ' Minute-microsecond or Minute.microsecond or Minute/microsecond '
Minute_second	String type, formatted as ' Minuter-second or Minute.second or Minute/second '
Hour_microsecond	String type, formatted as ' Hour-microsecond or Hourmicrosecond or Hour/microsecond '
Hour_second	String type, formatted as ' Hour-second or Hour.second or Hour/second '
Hour_minute	String type, formatted as ' Hourr-minute or Hour.minute or Hour/minute '
Day_microsecond	String type, formatted as ' Day-microsecond or Day.microsecond or Day/microsecond '
Day_second	String type, formatted as ' Day-second or Day.second or Day/second '
Day_minute	String type, formatted as ' Day-minute or Day.minute or Day/minute '
Day_hour	String type, formatted as ' Day-hour or day.hour or Day/hour '
Year_month	String type, formatted as ' year-month or year.month or Year/month '

The use of the MySQL Date_add () function