unable to append zero into id when updating attribute table

Question

I want to update attribute table BID column using below line

($id +002)

but it is not adding 00 at beginning. instead adding 2,3,4,5,...... I am very beginner and this is my first try to append zero zero into features table column. I am somehow manage to write this

'0000' || ($id + 5)

it adding zeros but changing exceeding the id length limits

Answer 1

You have to decide whether you want to have an integer or text field. If you want to do any arithemetics on the field, take integer, if you want trailing zeros, take a text field.

As a workaround, you can use an integer field, and use the field calculator to add a new, virtual field of type text, with this formula:

lpad( "<integer column name>" ,4,0)

This will make the field auto-updateable.

• Muhammad Faizan Khan: thanks @AndreJ is this possible to maintain 4 digit length and append '01' to every number. if the number like this you have 1, covert it to 0101.if you have 10 then covert it to 0110.
• Muhammad Faizan Khan: while i run your code[lpad("<integer BUILDINGID>",4,0)] it now given me null in data
• AndreJ: if the field is named id, the formula should be lpad( "id" ,4,0). You can select fields and functions in the right hand panel.
• Muhammad Faizan Khan: it didn't worked lpad("BUILDINGID",4,0)
• Muhammad Faizan Khan: and please tell me about my first comment