Mysql update time (plus or minus a period of time)

Mysql time addition and subtraction functions are date_add(), date_sub()

Definition and Usage

The DATE_ADD() function adds the specified interval to a date.

The DATE_SUB() function decrements a date by the specified interval.

grammar

DATE_ADD(date,INTERVAL expr type)

DATE_SUB(date,INTERVAL expr type)

 

The date parameter is a valid date expression.

The expr parameter is the time interval you wish to add.

The type parameter can have the following values:

Type value

MICROSECOND

SECOND

MINUTE

HOUR

DAY

WEEK

MONTH

QUARTER

YEAR

SECOND_MICROSECOND

MINUTE_MICROSECOND

MINUTE_SECOND

HOUR_MICROSECOND

HOUR_SECOND

HOUR_MINUTE

DAY_MICROSECOND

DAY_SECOND

DAY_MINUTE

DAY_HOUR

YEAR_MONTH

 

1. MySQL adds a time interval to the date: date_add()

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1. set @dt = now();
2. select date_add(@dt, interval 1 day); - add 1 day
3. select date_add(@dt, interval 1 hour); - add 1 hour
4. select date_add(@dt, interval 1 minute); - add 1 minute
5. select date_add(@dt, interval 1 second); - add 1 second
6. select date_add(@dt, interval 1 microsecond); - add 1 millisecond
7. select date_add(@dt, interval 1 week); - add 1 week
8. select date_add(@dt, interval 1 month); - add 1 month
9. select date_add(@dt, interval 1 quarter); - add 1 quarter
10. select date_add(@dt, interval 1 year); - add 1 year

Example: Update a certain time, add one week to each time

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1. UPDATE comment c set c.time = DATE_ADD(c.time, INTERVAL 7 DAY) ;

 

2. MySQL subtracts a time interval for the date: date_sub(), the format is similar to date_add()

Example: Update a certain time, reducing each time by one month

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1. UPDATE comment c set c.time = DATE_SUB(c.time, INTERVAL 1 MONTH)

 

You can also use these functions when inserting data. Such as

update sql:

update v_po_part r

set r.otdStandardTime = date_add(now(),interval 1 DAY)

where r.id ='57'

Insert sql: