SQL query doubt :removing prefix characters

Question

In SQL, how can I remove the first 4 characters of values of a specific column in a table. Coulmn name is Student Code and an example value id ABCD123Stu1231. I wan to remove first 4 chars from my table for all records

Please guide me

Answer 1

SELECT RIGHT(MyColumn, LEN(MyColumn) - 4) AS MyTrimmedColumn

Edit: To explain, RIGHT takes 2 arguments - the string (or column) to operate on, and the number of characters to return (starting at the "right" side of the string). LEN returns the length of the column data, and we subtract four so that our RIGHT function leaves the leftmost 4 characters "behind".

Hope this makes sense.

Edit again - I just read Andrew's response, and he may very well have interperpereted correctly, and I might be mistaken. If this is the case (and you want to UPDATE the table rather than just return doctored results), you can do this:

UPDATE MyTable
SET MyColumn = RIGHT(MyColumn, LEN(MyColumn) - 4)

He's on the right track, but his solution will keep the 4 characters at the start of the string, rather than discarding said 4 characters.

Answer 2

Try this:

update table YourTable
set YourField = substring(YourField, 5, len(YourField)-3);

Answer 3

Here's a simple mock-up of what you're trying to do :)

CREATE TABLE Codes
(
code1 varchar(10),
code2 varchar(10)
)

INSERT INTO Codes (CODE1, CODE2) vALUES ('ABCD1234','')


UPDATE Codes
SET code2 = SUBSTRING(Code1, 5, LEN(CODE1) -4)

So, use the last statement against the field you want to trim :)

The SUBSTRING function trims down Code1, starting at the FIFTH character, and continuing for the length of CODE1 less 4 (the number of characters skipped at the start).

Answer 4

Why use LEN so you have 2 string functions? All you need is character 5 on...

...SUBSTRING (Code1, 5, 8000)...