Introduction to common conversion functions in MySQL

cast function; Convert function.

Usage: CAST (expr as type), convert (Expr,type), convert (expr USING transcoding_name).

SELECT CONVERT (' abc ' USING UTF8);

convert varchar to int with cast (str as unsigned) str to a varchar type string.

For example, the usual percentage conversions:

Select CAST ((1/3) *100 as UNSIGNED) as percent from dual;

Result:33

MySQL type conversion function parameters: Cast (xxx as type), convert (XXX, type)
This type can be one of the following values:
binary[(N)]
char[(N)]
DATE
Datetime
DECIMAL
Signed [INTEGER]
Time
UNSIGNED [INTEGER]

Integer: Signed
unsigned integer: UNSIGNED
Binary, with binary prefix effect: binary
Character type, with parameters: CHAR ()
Date: Date
Time:
DateTime Date/Time type
Floating point number: DECIMAL

Binary STR is the abbreviated form of cast (str as BINARY):

mysql> SELECT BINARY ' a ' = ' a ';

0

Note: It is sometimes important to be aware of escaping when using: http://www.cnblogs.com/end/archive/2011/04/01/2002516.html

MySQL function Daquan: http://www.cnblogs.com/kissdodog/p/4168721.html

MySQL function Official document: https://dev.mysql.com/doc/refman/5.7/en/func-op-summary-ref.html

Introduction to common conversion functions in MySQL