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How to make MySQL table primary key auto increment with some prefix

Posted by: admin November 1, 2017 Leave a comment

Questions:

I have table like this

table
id Varchar(45) NOT NULL AUTO_INCREMENT PRIMARY KEY,
name CHAR(30) NOT NULL,

I want to increment my id field like 'LHPL001','LHPL002','LHPL003'… etc.
What should I have to do for that? Please let me know any possible way.

Answers:

If you really need this you can achieve your goal with help of separate table for sequencing (if you don’t mind) and a trigger.

Tables

CREATE TABLE table1_seq
(
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
);
CREATE TABLE table1
(
  id VARCHAR(7) NOT NULL PRIMARY KEY DEFAULT '0', name VARCHAR(30)
);

Now the trigger

DELIMITER $$
CREATE TRIGGER tg_table1_insert
BEFORE INSERT ON table1
FOR EACH ROW
BEGIN
  INSERT INTO table1_seq VALUES (NULL);
  SET NEW.id = CONCAT('LHPL', LPAD(LAST_INSERT_ID(), 3, '0'));
END$$
DELIMITER ;

Then you just insert rows to table1

INSERT INTO Table1 (name) 
VALUES ('Jhon'), ('Mark');

And you’ll have

|      ID | NAME |
------------------
| LHPL001 | Jhon |
| LHPL002 | Mark |

Here is SQLFiddle demo

Questions:
Answers:

Create a table with a normal numeric auto_increment ID, but either define it with ZEROFILL, or use LPAD to add zeroes when selecting. Then CONCAT the values to get your intended behavior. Example:

create table so (
 id int(3) unsigned zerofill not null auto_increment primary key,
 name varchar(30) not null
);

insert into so set name = 'John';
insert into so set name = 'Mark';

select concat('LHPL', id) as id, name from so;
+---------+------+
| id      | name |
+---------+------+
| LHPL001 | John |
| LHPL002 | Mark |
+---------+------+

Questions:
Answers:

I know it is late but I just want to share on what I have done for this. I’m not allowed to add another table or trigger so I need to generate it in a single query upon insert. For your case, can you try this query.

CREATE TABLE YOURTABLE(
IDNUMBER VARCHAR(7) NOT NULL PRIMARY KEY,
ENAME VARCHAR(30) not null
);

Perform a select and use this select query and save to the parameter @IDNUMBER

(SELECT IFNULL
     (CONCAT('LHPL',LPAD(
       (SUBSTRING_INDEX
        (MAX(`IDNUMBER`), 'LHPL',-1) + 1), 5, '0')), 'LHPL001')
    AS 'IDNUMBER' FROM YOURTABLE ORDER BY `IDNUMBER` ASC)

And then Insert query will be :

INSERT INTO YOURTABLE(IDNUMBER, ENAME) VALUES 
(@IDNUMBER, 'EMPLOYEE NAME');

The result will be the same as the other answer but the difference is, you will not need to create another table or trigger. I hope that I can help someone that have a same case as mine.