Comment diviser la chaîne de noms dans mysql ?

Question

Comment diviser la chaîne de noms dans mysql ?

Par exemple :

name
-----
Sachin ramesh tendulkar
Rahul dravid

Divisez le nom comme suit firstname,middlename,lastname :

firstname   middlename    lastname
---------  ------------   ------------
sachin     ramesh         tendulkar
rahul      dravid

Answer 1

DELIMITER $$

DROP FUNCTION IF EXISTS `split_name`$$

CREATE FUNCTION split_name (p_fullname TEXT, p_part INTEGER)
RETURNS TEXT
    READS SQL DATA
BEGIN
    DECLARE v_words INT UNSIGNED;
    DECLARE v_name TEXT;

    SET p_fullname=RTRIM(LTRIM(p_fullname));

    SET v_words=(SELECT SUM(LENGTH(p_fullname) - LENGTH(REPLACE(p_fullname, ' ', ''))+1));

    IF v_words=1 THEN 
        IF p_part=1 THEN
            SET v_name=p_fullname;
        ELSEIF p_part=2 THEN
            SET v_name=NULL;
        ELSEIF p_part=3 THEN
            SET v_name=NULL;
        ELSE
            SET v_name=NULL;
        END IF; 
    ELSEIF v_words=2 THEN 
        IF p_part=1 THEN
            SET v_name=SUBSTRING(p_fullname, 1, LOCATE(' ', p_fullname) - 1);
        ELSEIF p_part=2 THEN
            SET v_name=SUBSTRING(p_fullname, LOCATE(' ', p_fullname) + 1);
        ELSEIF p_part=3 THEN
            SET v_name=NULL;
        ELSE
            SET v_name=NULL;
        END IF; 
    ELSEIF v_words=3 THEN 
        IF p_part=1 THEN
            SET v_name=SUBSTRING(p_fullname, 1, LOCATE(' ', p_fullname) - 1);
        ELSEIF p_part=2 THEN
            SET p_fullname=SUBSTRING(p_fullname, LOCATE(' ', p_fullname) + 1);
            SET v_name=SUBSTRING(p_fullname, 1, LOCATE(' ', p_fullname) - 1);
        ELSEIF p_part=3 THEN
            SET p_fullname=REVERSE (SUBSTRING(p_fullname, LOCATE(' ', p_fullname) + 1));
            SET p_fullname=SUBSTRING(p_fullname, 1, LOCATE(' ', p_fullname) - 1);
            SET v_name=REVERSE(p_fullname);
        ELSE
            SET v_name=NULL;
        END IF; 
    ELSEIF v_words>3 THEN 
        IF p_part=1 THEN
            SET v_name=SUBSTRING(p_fullname, 1, LOCATE(' ', p_fullname) - 1);
        ELSEIF p_part=2 THEN
            SET p_fullname=REVERSE(SUBSTRING(p_fullname, LOCATE(' ', p_fullname) + 1));
            SET p_fullname=SUBSTRING(p_fullname, LOCATE(' ', p_fullname,SUBSTRING_INDEX(p_fullname,' ',1)+1) + 1);
            SET v_name=REVERSE(p_fullname);
        ELSEIF p_part=3 THEN
            SET p_fullname=REVERSE (SUBSTRING(p_fullname, LOCATE(' ', p_fullname) + 1));
            SET p_fullname=SUBSTRING(p_fullname, 1, LOCATE(' ', p_fullname) - 1);
            SET v_name=REVERSE(p_fullname);
        ELSE
            SET v_name=NULL;
        END IF;
    ELSE
        SET v_name=NULL;
    END IF;
 RETURN v_name; 
END;

SELECT split_name('Md. Obaidul Haque Sarker',1) AS first_name,
split_name('Md. Obaidul Haque Sarker',2) AS middle_name,
split_name('Md. Obaidul Haque Sarker',3) AS last_name

Answer 2

Basé sur les réponses précédentes et faire quelques modifications...

note :

p_delimiter doit être VARCHAR(1) couse CHAR(1) si est ' ' (espace) donne '' (supprime l'espace et renvoie une chaîne vide)

Utilisez plutôt LENGTH Je préfère CHAR_LENGTH ce qui est sûr pour les caractères multi-octets comme UTF

DROP FUNCTION IF EXISTS FN_SPLIT_STR;

DELIMITER ;;

CREATE FUNCTION FN_SPLIT_STR(
    p_input VARCHAR(2000), p_delimiter VARCHAR(1), p_position INT
)
    RETURNS VARCHAR(2000)
    DETERMINISTIC
BEGIN
    DECLARE chunks INT;
    SET chunks := CHAR_LENGTH(p_input) - CHAR_LENGTH(REPLACE(p_input, p_delimiter, '')) + 1;

    IF p_position > chunks THEN
        RETURN NULL;
    END IF;

    RETURN SUBSTRING_INDEX(SUBSTRING_INDEX(p_input, p_delimiter, p_position), p_delimiter, -1);
END;;

DELIMITER ;