The efficiency of int is significantly higher when comparing queries with time. Xiang Wen See http://www.jb51.net/article/29767.htm
However, when doing the project or directly in the database to view the data, it is obvious that the int is big, such as we want to
To view a user's registration time:
Select Reg_time from T_xx_users where user_id=1;
This time the return is an int value, can not intuitively see the specific times, so it involves the conversion of datetime and int,
There is also a date and time for PHP to be involved in corresponding conversions. This article summarizes briefly:
(1) PHP
int value:
Time (): is the number of seconds to return from the Unix era (00:00:00 GMT, January 1, 1970) to the current.
The number of seconds we want to get from January 1, 1970 to 2012-2-10 can be achieved by Strtotime (): Strtotime (' 2012-2-10 ');
Date value:
String date (string format [, int timestamp])
For example: direct date () returns the implementation of the current time, of course we can specify his format: for example, date (' y-m-d ', strtotime (' 2012-2-10 '));
Time Operation:
Date (' y-m-d h:i:s ', Strtotime (' +1 Week '));
Date (' y-m-d h:i:s ', Strtotime (' +5 hours '));
Date (' y-m-d h:i:s ', Strtotime (' next Monday));
Date (' y-m-d h:i:s ', Strtotime (' last Sunday '));
Date (' y-m-d h:i:s ', strtotime (' + 1 day ', 12313223));!! See int Strtotime (string time [, int now])
(2) MySQL:
Int->datetime
Select From_unixtime (int_time) from table;
datetime->int;
Select Unix_timestamp (date_time) from table;
Time Operation:
Select DayOfWeek (' 2012-2-2 '); Returns the day of the week one
Select DayOfMonth (' 2012-2-2 '); Returns the day ordinal of January
Select DayOfYear (' 2012-2-2 '); Returns the day ordinal of a year
Similar functions: Month () Day () hour () Week () ...
+ Date_add (Date,interval 2 days);
-Date_sub (Date,interval 2 days);
Time Format:
Date_format (Date,format)
Select Date_format (' 1997-10-04 22:23:00 ', '%W%M%Y ');
Other functions: Time_to_sec () sec_to_time () ...
The above describes my summer holiday English composition Php&mysql date operation, including my summer holiday English composition, I hope that the PHP tutorial interested in a friend helpful.
