Question

I have several thousands of rows that I’m loading into a database utilizing Pentaho. I must keep the string value length at 4 characters. The source file may only have a single character but it is still needed to keep the length at 4 characters to maintain consistency in the database.

Example:
Source: 10
Database expected results: 0010

I’m using a replace in string transformation or could use a java expression, which ever one works. Please help and provide a resolution utilizing either method (Regex or Javascript expression).

Thanks,

Answer 1

In Java you can use String.format(...) with a format specifier to pad your number with zeroes to 4 digits:

String.format("%04d", yournumber);

In Javascript you can use sprintf(...) for the same task:

var s = sprintf("%04d", yournumber);

So apparently sprintf() isn’t standard Javascript but is a library you can download if you like. You can always to do this to get your 4 digits though:

// take the last 4 digits from the right
var s = String("0000" + yournumber).slice(-4); 

And you could actually turn this into a simple left-padding function:

String.prototype.leftPad = function(paddingValue, paddingLength) {
   return (new Array(paddingLength + 1).join(paddingValue) + this).slice(-paddingLength);
};

var s = String(yournumber).leftPad("0", 4)