How to split the name string in mysql?

Question

I've separated this answer into two(2) methods. The first method will separate your fullname field into first, middle, and last names. The middle name will show as NULL if there is no middle name.

SELECT
   SUBSTRING_INDEX(SUBSTRING_INDEX(fullname, ' ', 1), ' ', -1) AS first_name,
   If(  length(fullname) - length(replace(fullname, ' ', ''))>1,  
       SUBSTRING_INDEX(SUBSTRING_INDEX(fullname, ' ', 2), ' ', -1) ,NULL) 
           as middle_name,
   SUBSTRING_INDEX(SUBSTRING_INDEX(fullname, ' ', 3), ' ', -1) AS last_name
FROM registeredusers

This second method considers the middle name as part of the lastname. We will only select a firstname and lastname column from your fullname field.

SELECT
   SUBSTRING_INDEX(SUBSTRING_INDEX(fullname, ' ', 1), ' ', -1) AS first_name,
    TRIM( SUBSTR(fullname, LOCATE(' ', fullname)) ) AS last_name
FROM registeredusers

There's a bunch of cool things you can do with substr, locate, substring_index, etc. Check the manual for some real confusion. http://dev.mysql.com/doc/refman/5.0/en/string-functions.html

There is no string split function in MySQL. so you have to create your own function. This will help you. More details at this link.

Function:

CREATE FUNCTION SPLIT_STR(
  x VARCHAR(255),
  delim VARCHAR(12),
  pos INT
)
RETURNS VARCHAR(255)
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos),
       LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1),
       delim, '');

Usage:

SELECT SPLIT_STR(string, delimiter, position)

Example:

SELECT SPLIT_STR('a|bb|ccc|dd', '|', 3) as third;

+-------+
| third |
+-------+
| ccc   |
+-------+

Well, nothing I used worked, so I decided creating a real simple split function, hope it helps:

DECLARE inipos INTEGER;
DECLARE endpos INTEGER;
DECLARE maxlen INTEGER;
DECLARE item VARCHAR(100);
DECLARE delim VARCHAR(1);

SET delim = '|';
SET inipos = 1;
SET fullstr = CONCAT(fullstr, delim);
SET maxlen = LENGTH(fullstr);

REPEAT
    SET endpos = LOCATE(delim, fullstr, inipos);
    SET item =  SUBSTR(fullstr, inipos, endpos - inipos);

    IF item <> '' AND item IS NOT NULL THEN           
        USE_THE_ITEM_STRING;
    END IF;
    SET inipos = endpos + 1;
UNTIL inipos >= maxlen END REPEAT;

Here is the split function I use:

--
-- split function
--    s   : string to split
--    del : delimiter
--    i   : index requested
--

DROP FUNCTION IF EXISTS SPLIT_STRING;

DELIMITER $

CREATE FUNCTION 
   SPLIT_STRING ( s VARCHAR(1024) , del CHAR(1) , i INT)
   RETURNS VARCHAR(1024)
   DETERMINISTIC -- always returns same results for same input parameters
    BEGIN

        DECLARE n INT ;

        -- get max number of items
        SET n = LENGTH(s) - LENGTH(REPLACE(s, del, '')) + 1;

        IF i > n THEN
            RETURN NULL ;
        ELSE
            RETURN SUBSTRING_INDEX(SUBSTRING_INDEX(s, del, i) , del , -1 ) ;        
        END IF;

    END
$

DELIMITER ;


SET @agg = "G1;G2;G3;G4;" ;

SELECT SPLIT_STRING(@agg,';',1) ;
SELECT SPLIT_STRING(@agg,';',2) ;
SELECT SPLIT_STRING(@agg,';',3) ;
SELECT SPLIT_STRING(@agg,';',4) ;
SELECT SPLIT_STRING(@agg,';',5) ;
SELECT SPLIT_STRING(@agg,';',6) ;