Trick Zero Pad Numbers
There are many ways to add zero in font of the number (zero pad) in java script, php, and postgres. I just found little trick and really simple. Let's say we need to get format a number with leading zero, e.g: total digits of number will be 4. Java Script: var no= 28; number= String("0000" + no).slice(-4); // result 0028 PHP: $no = "28"; echo str_pad($no, 4, '0', STR_PAD_LEFT); //result 0028 Postgres Sql: select (substring('0000' || CAST(CAST (01 AS int) as varchar) from '....$')) from m_order It is also applicable to padding with any character, not just zeros.