[sql] How do I remove the first characters of a specific column in a table?

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

Please guide me

There's the built-in trim function that is perfect for the purpose.

SELECT trim(both 'ag' from 'asdfg');
btrim 
-------
 sdf
(1 riga)

http://www.postgresql.org/docs/8.1/static/functions-string.html

You Can also do this in SQL..

substring(StudentCode,4,len(StudentCode))

syntax

substring (ColumnName,<Number of starting Character which u want to remove>,<length of given string>)

The Complete thing

DECLARE @v varchar(10)

SET @v='#temp'

select STUFF(@v, 1, 1, '')
WHERE LEFT(@v,1)='#'

If you have to remove the first few characters that are preceded by a special character like #, this is a good one:

UPDATE tblInvalidID
SET [ColumnName] =stuff(ColumnName, 1, charindex('#', ColumnName), ' ') 

Try this:

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

Try this. 100% working

UPDATE Table_Name
SET RIGHT(column_name, LEN(column_name) - 1)

Stuff(someColumn, 1, 4, '')

This says, starting with the first 1 character position, replace 4 characters with nothing ''

The top answer is not suitable when values may have length less than 4.

In T-SQL

You will get "Invalid length parameter passed to the right function" because it doesn't accept negatives. Use a CASE statement:

SELECT case when len(foo) >= 4 then RIGHT(foo, LEN(foo) - 4) else '' end AS myfoo from mytable;

In Postgres

Values less than 4 give the surprising behavior below instead of an error, because passing negative values to RIGHT trims the first characters instead of the entire string. It makes more sense to use RIGHT(MyColumn, -5) instead.

An example comparing what you get when you use the top answer's "length - 5" instead of "-5":

create temp table foo (foo) as values ('123456789'),('12345678'),('1234567'),('123456'),('12345'),('1234'),('123'),('12'),('1'), ('');

select foo, right(foo, length(foo) - 5), right(foo, -5) from foo;

foo       len(foo) - 5  just -5   
--------- ------------  -------     
123456789 6789          6789 
12345678  678           678  
1234567   67            67   
123456    6             6    
12345                       
1234      234               
123       3                 
12                          
1                           

It would be good to share, For DB2 use: INSERT(someColumn, 1, 4, '')

Stuff is not supported in DB2

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

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

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).