Extract email address from string using tsql

Question

I\'m trying to extract email addresses from an existing comments field and put it into its own column. The string may be something like this \"this is an example comment wit

Answer 1

For strings that contain new line characters I modified Felix's answer using PATINDEX to search for the first control character rather than white space.

I also had to modify the Right field to subtract the correct amount of text.

    WITH CteEmail(email) AS(
        SELECT 'example string with new lines

    Email: some.example@email.address.com
(first email address - should be returned)

    Email: another@test.co.uk
(other email addresses should be ignored

more example text' UNION ALL
        SELECT 'Email: some.example@email.address.com' UNION ALL
        SELECT 'someemail@domain.org' UNION ALL
        SELECT 'some text someemail@domain.org some text' UNION ALL
        SELECT 'no email'
    )
    ,CteStrings AS(
        SELECT
            [Left] = LEFT(email, CHARINDEX('@', email, 0) - 1),
            Reverse_Left = REVERSE(LEFT(email, CHARINDEX('@', email, 0) - 1)),
            [Right] = RIGHT(email, LEN(email) - CHARINDEX('@', email, 0) + 1 )
        FROM CteEmail
        WHERE email LIKE '%@%'
    )
    SELECT *,
        REVERSE(
            SUBSTRING(Reverse_Left, 0, 
                CASE
                    WHEN PATINDEX('%[' + CHAR(10)+'- ]%', Reverse_Left) = 0 THEN LEN(Reverse_Left) + 1
                    ELSE PATINDEX('%[' + CHAR(0)+'- ]%', Reverse_Left)
                END
            )
        )
        +
        SUBSTRING([Right], 0,
            CASE
                WHEN PATINDEX('%[' + CHAR(0)+'- ]%', [Right]) = 0 THEN LEN([Right]) + 1
                ELSE PATINDEX('%[' + CHAR(0)+'- ]%', [Right])
            END
        )
    FROM CteStrings