mysql where datetime

Int (1). 4 byte storage, the length of the int is 4 bytes, the storage space is less than datatime, the int index storage space is also relatively small, the sorting and the query efficiency is relatively higher a little(2) The readability is

This content is transferred from a Sina blog article later I will optimize the content Http://blog.sina.com.cn/s/blog_6d39dc6f0100m7eo.html In addition to the now () function to get the current datetime, MySQL has the following function:

usually storage time with datetime type, and now many systems also use int storage time, what difference do they have? Individuals prefer to use int this is good for date calculations, so let's look at the kind of things that would be better. int(1).

ASCII (str) returns the ASCII value of the first character of the string str (0 if str is an empty string) mysqlgt; selectASCII ( ASCII (str) returns the ASCII value of the first character of the string str (0 if str is an empty string) mysqlgt;

ASCII (str)Returns the ASCII value of the first character of the string 'str' (0 is returned when 'str' is an empty string)Mysql> selectASCII ('2 ');-> 50Mysql> select ASCII (2 );->50Mysql> select ASCII ('dete ');-> 100ORD (str)If the string 'str'

How do I represent the current time in MySQL?In fact, the expression is still quite a lot of, summarized as follows:Current_timestampCurrent_timestamp ()Now ()LocalTimeLocalTime ()LocaltimestampLocaltimestamp ()Ii. Comparison of Timestamp and

During MySQL query time period, it will be more efficient to select INT, or will it be more efficient to select DateTime? To solve this problem, we will perform a test to see whether INT or DateTime should be used in the MySQL query

Introduction to timestamp basic knowledge Variant of the timestamp1,timestamp DEFAULT current_timestamp on UPDATE current_timestamp refreshes this data column when new records are created and existing records are modified 2,timestamp default

http://tsecer.blog.163.com/blog/static/150181720160117355684/a grammatical analysis of time comparisonIn MySQL, the usual time is an essential type, and a special place of this type is its comparison function. In fact, even if the comparison

Description of whether the MySQL time field uses INT or DateTime. When parsing DEDECMS today, we found that the MYSQL time fields of deder all use 'senddata' int (10) unsignedNOTNULLDEFAULT0. then we found this article online, it seems that if the