WordPress functions.php shortcode is not working [closed]

Finally it worked.

To ensure that, all following conditions must be met:

  • declarations must be in lowercase
  • do not use echo but return the content
  • square brackets are required even in the shortcode block.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)