Insert or Update When Exists Mysql

Create a UNIQUE constraint on your subs_email column, if one does not already exist:

ALTER TABLE subs ADD UNIQUE (subs_email)

Use INSERT … ON DUPLICATE KEY UPDATE:

INSERT INTO subs

  (subs_name, subs_email, subs_birthday)

VALUES

  (?, ?, ?)

ON DUPLICATE KEY UPDATE

  subs_name     = VALUES(subs_name),

  subs_birthday = VALUES(subs_birthday)