Php+mysql How to convert Date-time (Unix timestamp and format date) _php tips

Programmers who write Php+mysql know there is a time difference, UNIX timestamp and format date are two time representations we often deal with, Unix timestamp storage, processing convenient, but not intuitive, format date intuitive, but not as easy to deal with the Unix time stamp so freely, So there are times when you need to convert to each other, and there are several ways to transform each other.

One, complete in MySQL

This way in the MySQL query statement conversion, the advantage is not to occupy PHP parser parsing time, fast, the disadvantage is only used in database query, there are limitations.

1. UNIX timestamp converted to date function: From_unixtime ()

General form: Select From_unixtime (1156219870);

2. Date conversion to UNIX timestamp with function: Unix_timestamp ()

General form: Select unix_timestamp (' 2006-11-04 12:23:00′);

For example: MySQL Query the number of records of the day:

$sql = "SELECT * FROM Message Where date_format (From_unixtime (chattime), '%y-%m-%d ') = Date_format (now (), '%y-%m-%d ') ORDER BY id DESC ";

Of course, you can also choose to convert in PHP, the following is said in PHP conversion.

Second, in PHP to complete

This way in the PHP program to complete the conversion, the advantage is that no matter is not the database query to obtain the data can be converted, the scope of the conversion is unrestricted, the disadvantage is to occupy the parsing time of the PHP parser, the speed is relatively slow.

1. UNIX timestamp converted to date function: Date ()

General form: Date (' y-m-d h:i:s ', 1156219870);

2. Date conversion to Unix timestamp with function: Strtotime ()

General form: Strtotime (' 2010-03-24 08:15:42 ');