IndexOf function in t-Sql

Question

Given an email address column, I need to find the position of the @ sign for substringing.

What is the indexof function, for strings in t-sql.

Looking for something that returns the position of a substring within a string.

in c#

var s = "abcde";
s.IndexOf('c'); // yields 2

Answer 1

CHARINDEX is what you are looking for

select CHARINDEX('@', '[email protected]')


-----------
8

(1 row(s) affected)

Answer 2

I believe you want to use CHARINDEX. You can read about it here.

Answer 3

You can use either CHARINDEX or PATINDEX to return the starting position of the specified expression in a character string.

CHARINDEX('bar', 'foobar') == 4
PATINDEX('%bar%', 'foobar') == 4

Mind that you need to use the wildcards in PATINDEX on either side.

Answer 4

One very small nit to pick:

The RFC for email addresses allows the first part to include an "@" sign if it is quoted. Example:

"john@work"@myemployer.com

This is quite uncommon, but could happen. Theoretically, you should split on the last "@" symbol, not the first:

SELECT LEN(EmailField) - CHARINDEX('@', REVERSE(EmailField)) + 1

More information:

http://en.wikipedia.org/wiki/Email%5Faddress