Syntax
CONCAT(str1, str2, ...)
Purpose
CONCAT() concatenates multiple strings into one string. If all arguments are non-binary strings, the result is a non-binary string. If any argument is a binary string, the result is a binary string. Numeric arguments are converted into equivalent non-binary strings.
If any argument is NULL, the function returns NULL.
Examples
obclient> SELECT
CONCAT('test','obclient', '1.0'),
CONCAT('test','obclient', NULL)
\G
*************************** 1. row ***************************
CONCAT('test','obclient', '1.0'): testobclient1.0
CONCAT('test','obclient', NULL): NULL
1 row in set