Syntax
------ 
CONVERT(expr,type), CONVERT(expr USING transcoding_name)
 
Description
----------- 
The CONVERT() and CAST() functions take a value of one type
and produce a value of another type.
 
The type can be one of the following values:
BINARY
CHAR
DATE
DATETIME 
DECIMAL[(M[,D])]
DOUBLE 
FLOAT — From MariaDB 10.4.5
INTEGER 
Short for SIGNED INTEGER
 
SIGNED [INTEGER]
TIME 
UNSIGNED [INTEGER]
 
Note that in MariaDB, INT and INTEGER are the same thing.
 
BINARY produces a string with the BINARY data type. If the
optional length is given, BINARY(N) causes the cast to use
no more than N bytes of the argument. Values shorter than
the given number in bytes are padded with 0x00 bytes to make
them equal the length value.
 
CHAR(N) causes the cast to use no more than the number of
characters given in the argument.
 
The main difference between the CAST() and CONVERT() is that
CONVERT(expr,type) is ODBC syntax while CAST(expr as type)
and CONVERT(... USING ...) are SQL92 syntax.
 
CONVERT() with USING is used to convert data between
different character sets. In MariaDB, transcoding names are
the same as the
corresponding character set names. For example, this
statement
converts the string 'abc' in the default character set to
the
corresponding string in the utf8 character set:
 
SELECT CONVERT('abc' USING utf8);
 
Examples
-------- 
SELECT enum_col FROM tbl_name 
ORDER BY CAST(enum_col AS CHAR);
 
Converting a BINARY to string to permit the LOWER function
to work:
 
SET @x = 'AardVark';
 
SET @x = BINARY 'AardVark';
 
SELECT LOWER(@x), LOWER(CONVERT (@x USING latin1));
+-----------+----------------------------------+
| LOWER(@x) | LOWER(CONVERT (@x USING latin1)) |
+-----------+----------------------------------+
| AardVark | aardvark |
+-----------+----------------------------------+
 


URL: https://mariadb.com/kb/en/convert/