SQL SUBSTRING vs RIGHT - Best Practice

Question

I'm trying to find out the best practice when removing characters from the start of a string.

In some languages, you can use MID without a length parameter however, in TSQL the length is required.

Considering the following code, what is the best practise? (The hex string is variable length)

DECLARE @sHex VARCHAR(66)
SET @sHex = '0x7E260F3DA734AD4BD816B88F485CE501D843DF067C8EDCB8AC7DAD331852E04D'

PRINT RIGHT(@sHex,LEN(@sHex) -2)
PRINT SUBSTRING(@sHex,3,LEN(@sHex) -2)
PRINT SUBSTRING(@sHex,3,65535)

Answer 1

Well, the first is more expressive of your intent. The last is clearly messy (hard-coded length etc). I doubt you'd find much performance difference between the first & second, so I'd use the simplest - RIGHT.

Of course, if you are doing this lots, you could write a udf that encapsulates this - then if you change your mind you only have one place to change...

Answer 2

+1 on the right function, it is much clearer what you want to do

Answer 3

I would use the right function as it better shows your intent. The substring function is best used for extracting strings from the middle of a longer string.

Answer 4

I use the second SUBSTRING because it is more portable. Not all dbms had LEFT and RIGHT.