PHP and MySQL date time (Unix timestamp, formatted date) conversion method

Programmers who have written php+mysql know that there is a time lag, Unix timestamps and formatted dates are two time representations that we often deal with, Unix timestamp storage, easy processing, but not intuitive, formatted date intuitive, but not as easy to handle as the Unix timestamp, So sometimes it's necessary to convert each other, and here are some ways to convert 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 function: Unix_timestamp ()

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

Example: MySQL Query the number of records on the day:

$sql = "SELECT *" from the 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, complete in PHP

This way in the PHP program to complete the conversion, the advantage is that the database is not the data can be converted, the scope of the conversion is not limited, 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 function: Strtotime ()

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

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