CONCAT(str1,str2,...)
Returns the string that results from concatenating the arguments. Returns NULL if any argument is NULL. May have one or more arguments. If all arguments are non-binary strings, the result is a non-binary string. If the arguments include any binary strings, the result is a binary string. A numeric argument is converted to its equivalent binary string form.
mysql> SELECT CONCAT('My', 'S', 'QL');
        -> 'MySQL'
mysql> SELECT CONCAT('My', NULL, 'QL');
        -> NULL
mysql> SELECT CONCAT(14.3);
        -> '14.3'

CONCAT_WS(separator,str1,str2,...)
CONCAT_WS() stands for CONCAT With Separator and is a special form of CONCAT(). The first argument is the separator for the rest of the arguments. The separator is added between the strings to be concatenated. The separator can be a string as can the rest of the arguments. If the separator is NULL, the result is NULL. The function skips any NULL values after the separator argument.
mysql> SELECT CONCAT_WS(',','First name','Second name','Last Name');
        -> 'First name,Second name,Last Name'
mysql> SELECT CONCAT_WS(',','First name',NULL,'Last Name');
        -> 'First name,Last Name'

select CONCAT("http://URL.COM/",UID1,"?ie=someparam&tag=",UID1) as MYLINK from TABLE1 WHERE УСЛОВИЕ;

mysql> SELECT SUBSTRING('foobarbar' FROM 4);
        -> 'barbar'

UPDATE table SET url2 =  CONCAT("http://othertext.com/otherfolder/", SUBSTRING(url1 FROM 27),"?ie=someparam&tag=", SUBSTRING(url1 FROM 27))
WHERE условие;