Sql script to find invalid email addresses

SqlValidationEmail

Sql Problem Overview


A data import was done from an access database and there was no validation on the email address field. Does anyone have an sql script that can return a list of invalid email addresses (missing @, etc).

Sql Solutions


Solution 1 - Sql

SELECT * FROM people WHERE email NOT LIKE '%_@__%.__%'

Anything more complex will likely return false negatives and run slower.

Validating e-mail addresses in code is virtually impossible.

EDIT: Related questions

Solution 2 - Sql

Here is a quick and easy solution:

CREATE FUNCTION dbo.vaValidEmail(@EMAIL varchar(100))
                                   
RETURNS bit as
BEGIN     
  DECLARE @bitRetVal as Bit
  IF (@EMAIL <> '' AND @EMAIL NOT LIKE '_%@__%.__%')
	 SET @bitRetVal = 0  -- Invalid
  ELSE 
	SET @bitRetVal = 1   -- Valid
  RETURN @bitRetVal
END 

Then you can find all rows by using the function:

SELECT * FROM users WHERE dbo.vaValidEmail(email) = 0

If you are not happy with creating a function in your database, you can use the LIKE-clause directly in your query:

SELECT * FROM users WHERE email NOT LIKE '_%@__%.__%'

Source

Solution 3 - Sql

I find this simple T-SQL query useful for returning valid e-mail addresses

SELECT email
FROM People
WHERE email LIKE '%_@__%.__%' 
    AND PATINDEX('%[^a-z,0-9,@,.,_]%', REPLACE(email, '-', 'a')) = 0

The PATINDEX bit eliminates all e-mail addresses containing characters that are not in the allowed a-z, 0-9, '@', '.', '_' & '-' set of characters.

It can be reversed to do what you want like this:

SELECT email
FROM People
WHERE NOT (email LIKE '%_@__%.__%' 
    AND PATINDEX('%[^a-z,0-9,@,.,_]%', REPLACE(email, '-', 'a')) = 0)

Solution 4 - Sql

select
    email 
from loginuser where
patindex ('%[ &'',":;!+=\/()<>]*%', email) > 0  -- Invalid characters
or patindex ('[@.-_]%', email) > 0   -- Valid but cannot be starting character
or patindex ('%[@.-_]', email) > 0   -- Valid but cannot be ending character
or email not like '%@%.%'   -- Must contain at least one @ and one .
or email like '%..%'        -- Cannot have two periods in a row
or email like '%@%@%'       -- Cannot have two @ anywhere
or email like '%.@%' or email like '%@.%' -- Cant have @ and . next to each other
or email like '%.cm' or email like '%.co' -- Unlikely. Probably typos 
or email like '%.or' or email like '%.ne' -- Missing last letter

This worked for me. Had to apply rtrim and ltrim to avoid false positives.

Source: http://sevenwires.blogspot.com/2008/09/sql-how-to-find-invalid-email-in-sql.html

Postgres version:

select user_guid, user_guid email_address, creation_date, email_verified, active
from user_data where
length(substring (email_address from '%[ &'',":;!+=\/()<>]%')) > 0  -- Invalid characters
or length(substring (email_address from '[@.-_]%')) > 0   -- Valid but cannot be starting character
or length(substring (email_address from '%[@.-_]')) > 0   -- Valid but cannot be ending character
or email_address not like '%@%.%'   -- Must contain at least one @ and one .
or email_address like '%..%'        -- Cannot have two periods in a row
or email_address like '%@%@%'       -- Cannot have two @ anywhere
or email_address like '%.@%' or email_address like '%@.%' -- Cant have @ and . next to each other
or email_address like '%.cm' or email_address like '%.co' -- Unlikely. Probably typos 
or email_address like '%.or' or email_address like '%.ne' -- Missing last letter
;

Solution 5 - Sql

MySQL

SELECT * FROM `emails` WHERE lower(`email`)
NOT REGEXP '[-a-z0-9~!$%^&*_=+}{\\\'?]+(\\.[-a-z0-9~!$%^&*_=+}{\\\'?]+)*@([a-z0-9_][-a-z0-9_]*(\\.[-a-z0-9_]+)*\\.(aero|arpa|biz|com|coop|edu|gov|info|int|mil|museum|name|net|org|pro|travel|mobi|[a-z][a-z])|([0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}))(:[0-9]{1,5})?'

Solution 6 - Sql

On sql server 2016 and up

CREATE FUNCTION [DBO].[F_IsEmail] (
 @EmailAddr varchar(360) -- Email address to check
)   RETURNS BIT -- 1 if @EmailAddr is a valid email address

AS BEGIN
DECLARE @AlphabetPlus VARCHAR(255)
      , @Max INT -- Length of the address
      , @Pos INT -- Position in @EmailAddr
      , @OK BIT  -- Is @EmailAddr OK
-- Check basic conditions
IF @EmailAddr IS NULL 
   OR @EmailAddr NOT LIKE '[0-9a-zA-Z]%@__%.__%' 
   OR @EmailAddr LIKE '%@%@%' 
   OR @EmailAddr LIKE '%..%' 
   OR @EmailAddr LIKE '%.@' 
   OR @EmailAddr LIKE '%@.' 
   OR @EmailAddr LIKE '%@%.-%' 
   OR @EmailAddr LIKE '%@%-.%' 
   OR @EmailAddr LIKE '%@-%' 
   OR CHARINDEX(' ',LTRIM(RTRIM(@EmailAddr))) > 0
       RETURN(0)



declare @AfterLastDot varchar(360);
declare @AfterArobase varchar(360);
declare @BeforeArobase varchar(360);
declare @HasDomainTooLong bit=0;

--Control des longueurs et autres incoherence
set @AfterLastDot=REVERSE(SUBSTRING(REVERSE(@EmailAddr),0,CHARINDEX('.',REVERSE(@EmailAddr))));
if	len(@AfterLastDot) not between 2 and 17
RETURN(0);

set @AfterArobase=REVERSE(SUBSTRING(REVERSE(@EmailAddr),0,CHARINDEX('@',REVERSE(@EmailAddr))));
if len(@AfterArobase) not between 2 and 255
RETURN(0);

select top 1 @BeforeArobase=value from  string_split(@EmailAddr, '@');
if len(@AfterArobase) not between 2 and 255
RETURN(0);

--Controle sous-domain pas plus grand que 63
select top 1 @HasDomainTooLong=1 from string_split(@AfterArobase, '.') where LEN(value)>63
if @HasDomainTooLong=1
return(0);

--Control de la partie locale en detail
SELECT @AlphabetPlus = 'abcdefghijklmnopqrstuvwxyz01234567890!#$%&‘*+-/=?^_`.{|}~'
     , @Max = LEN(@BeforeArobase)
     , @Pos = 0
     , @OK = 1


WHILE @Pos < @Max AND @OK = 1 BEGIN
    SET @Pos = @Pos + 1
    IF @AlphabetPlus NOT LIKE '%' + SUBSTRING(@BeforeArobase, @Pos, 1) + '%' 
        SET @OK = 0
END

if @OK=0
RETURN(0);

--Control de la partie domaine en detail
SELECT @AlphabetPlus = 'abcdefghijklmnopqrstuvwxyz01234567890-.'
     , @Max = LEN(@AfterArobase)
     , @Pos = 0
     , @OK = 1

WHILE @Pos < @Max AND @OK = 1 BEGIN
    SET @Pos = @Pos + 1
    IF @AlphabetPlus NOT LIKE '%' + SUBSTRING(@AfterArobase, @Pos, 1) + '%' 
        SET @OK = 0
END

if @OK=0
RETURN(0);







return(1);



END

Solution 7 - Sql

I find this approach more intuitive:

CREATE FUNCTION [dbo].[ContainsVailidEmail] (@Input varchar(250))
RETURNS bit
AS
BEGIN
  RETURN CASE
    WHEN @Input LIKE '%_@__%.__%' THEN 1
    ELSE 0
  END
END

I call it using the following:

SELECT [dbo].[ContainsVailidEmail] (Email) FROM [dbo].[User]

OR

If you are only going to use this once then why not it as a Computed Column, with the following specification:

(case when [Email] like '%_@__%.__%' then (1) else (0) end)

Then you can just use it without needing to call a function.

Solution 8 - Sql

SELECT Email FROM Employee WHERE NOT REGEXP_LIKE(Email, ‘[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}’, ‘i’);

Solution 9 - Sql

I propose my function :

CREATE FUNCTION [REC].[F_IsEmail] (
 @EmailAddr varchar(360) -- Email address to check
)   RETURNS BIT -- 1 if @EmailAddr is a valid email address

AS BEGIN
DECLARE @AlphabetPlus VARCHAR(255)
      , @Max INT -- Length of the address
      , @Pos INT -- Position in @EmailAddr
      , @OK BIT  -- Is @EmailAddr OK
-- Check basic conditions
IF @EmailAddr IS NULL 
   OR @EmailAddr NOT LIKE '[0-9a-zA-Z]%@__%.__%' 
   OR @EmailAddr LIKE '%@%@%' 
   OR @EmailAddr LIKE '%..%' 
   OR @EmailAddr LIKE '%.@' 
   OR @EmailAddr LIKE '%@.' 
   OR @EmailAddr LIKE '%@%.-%' 
   OR @EmailAddr LIKE '%@%-.%' 
   OR @EmailAddr LIKE '%@-%' 
   OR CHARINDEX(' ',LTRIM(RTRIM(@EmailAddr))) > 0
       RETURN(0)



declare @AfterLastDot varchar(360);
declare @AfterArobase varchar(360);
declare @BeforeArobase varchar(360);
declare @HasDomainTooLong bit=0;

--Control des longueurs et autres incoherence
set @AfterLastDot=REVERSE(SUBSTRING(REVERSE(@EmailAddr),0,CHARINDEX('.',REVERSE(@EmailAddr))));
if	len(@AfterLastDot) not between 2 and 17
RETURN(0);

set @AfterArobase=REVERSE(SUBSTRING(REVERSE(@EmailAddr),0,CHARINDEX('@',REVERSE(@EmailAddr))));
if len(@AfterArobase) not between 2 and 255
RETURN(0);

select top 1 @BeforeArobase=value from  string_split(@EmailAddr, '@');
if len(@AfterArobase) not between 2 and 255
RETURN(0);

--Controle sous-domain pas plus grand que 63
select top 1 @HasDomainTooLong=1 from string_split(@AfterArobase, '.') where LEN(value)>63
if @HasDomainTooLong=1
return(0);

--Control de la partie locale en detail
SELECT @AlphabetPlus = 'abcdefghijklmnopqrstuvwxyz01234567890!#$%&‘*+-/=?^_`.{|}~'
     , @Max = LEN(@BeforeArobase)
     , @Pos = 0
     , @OK = 1


WHILE @Pos < @Max AND @OK = 1 BEGIN
    SET @Pos = @Pos + 1
    IF @AlphabetPlus NOT LIKE '%' + SUBSTRING(@BeforeArobase, @Pos, 1) + '%' 
        SET @OK = 0
END

if @OK=0
RETURN(0);

--Control de la partie domaine en detail
SELECT @AlphabetPlus = 'abcdefghijklmnopqrstuvwxyz01234567890-.'
     , @Max = LEN(@AfterArobase)
     , @Pos = 0
     , @OK = 1

WHILE @Pos < @Max AND @OK = 1 BEGIN
    SET @Pos = @Pos + 1
    IF @AlphabetPlus NOT LIKE '%' + SUBSTRING(@AfterArobase, @Pos, 1) + '%' 
        SET @OK = 0
END

if @OK=0
RETURN(0);

return(1);

END

Solution 10 - Sql

SELECT EmailAddress AS ValidEmail
FROM Contacts
WHERE EmailAddress LIKE '%_@__%.__%'
        AND PATINDEX('%[^a-z,0-9,@,.,_,\-]%', EmailAddress) = 0
GO

Please check this link: https://blog.sqlauthority.com/2017/11/12/validate-email-address-sql-server-interview-question-week-147/

Solution 11 - Sql

sel 'unismankur@yahoo#.co.in' as Email, 
case 
    when Email not like  '%@xx%' 
    AND  Email like  '%@%' 
    AND  CHAR_LENGTH(
     oTranslate(
      trim( Email),
      '._-@0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
      '')
     ) = 0
     then 'N' else 'Y'  end as Invalid_Email_Ind;

This works very well for me.

Solution 12 - Sql

select * from users 
WHERE NOT
(     CHARINDEX(' ',LTRIM(RTRIM([Email]))) = 0 
AND  LEFT(LTRIM([Email]),1) <> '@' 
AND  RIGHT(RTRIM([Email]),1) <> '.' 
AND  CHARINDEX('.',[Email],CHARINDEX('@',[Email])) - CHARINDEX('@',[Email]) > 1 
AND  LEN(LTRIM(RTRIM([Email]))) - LEN(REPLACE(LTRIM(RTRIM([Email])),'@','')) = 1 
AND  CHARINDEX('.',REVERSE(LTRIM(RTRIM([Email])))) >= 3 
AND  (CHARINDEX('.@',[Email]) = 0 AND CHARINDEX('..',[Email]) = 0) 

Solution 13 - Sql

go

create proc GetEmail

@name varchar(22),
@gmail varchar(22)

as

begin

declare @a varchar(22)

set select @a=substring(@gmail,charindex('@',@gmail),len(@gmail)-charindex('@',@gmail)+1)

if (@a = 'gmail.com)

insert into table_name values(@name,@gmail)

else

print 'please enter valid email address'

end

Solution 14 - Sql

I know the post is old but after a 3 months time and with various email combinations I came across, able to make this sql for validating Email IDs.

CREATE FUNCTION [dbo].[isValidEmailFormat]
(
    @EmailAddress varchar(500)
)
RETURNS bit
AS
BEGIN
	DECLARE @Result bit

	SET @EmailAddress = LTRIM(RTRIM(@EmailAddress));
	SELECT @Result =
	CASE WHEN
	CHARINDEX(' ',LTRIM(RTRIM(@EmailAddress))) = 0
	AND LEFT(LTRIM(@EmailAddress),1) <> '@'
	AND RIGHT(RTRIM(@EmailAddress),1) <> '.'
	AND LEFT(LTRIM(@EmailAddress),1) <> '-'
	AND CHARINDEX('.',@EmailAddress,CHARINDEX('@',@EmailAddress)) - CHARINDEX('@',@EmailAddress) > 2	
	AND LEN(LTRIM(RTRIM(@EmailAddress))) - LEN(REPLACE(LTRIM(RTRIM(@EmailAddress)),'@','')) = 1
	AND CHARINDEX('.',REVERSE(LTRIM(RTRIM(@EmailAddress)))) >= 3
	AND (CHARINDEX('.@',@EmailAddress) = 0 AND CHARINDEX('..',@EmailAddress) = 0)
	AND (CHARINDEX('-@',@EmailAddress) = 0 AND CHARINDEX('..',@EmailAddress) = 0)
	AND (CHARINDEX('_@',@EmailAddress) = 0 AND CHARINDEX('..',@EmailAddress) = 0)
	AND ISNUMERIC(SUBSTRING(@EmailAddress, 1, 1)) = 0
	AND CHARINDEX(',', @EmailAddress) = 0
	AND CHARINDEX('!', @EmailAddress) = 0
	AND CHARINDEX('-.', @EmailAddress)=0
	AND CHARINDEX('%', @EmailAddress)=0
	AND CHARINDEX('#', @EmailAddress)=0
	AND CHARINDEX('$', @EmailAddress)=0
	AND CHARINDEX('&', @EmailAddress)=0
	AND CHARINDEX('^', @EmailAddress)=0
	AND CHARINDEX('''', @EmailAddress)=0
	AND CHARINDEX('\', @EmailAddress)=0
	AND CHARINDEX('/', @EmailAddress)=0
	AND CHARINDEX('*', @EmailAddress)=0
	AND CHARINDEX('+', @EmailAddress)=0
	AND CHARINDEX('(', @EmailAddress)=0
	AND CHARINDEX(')', @EmailAddress)=0
	AND CHARINDEX('[', @EmailAddress)=0
	AND CHARINDEX(']', @EmailAddress)=0
	AND CHARINDEX('{', @EmailAddress)=0
	AND CHARINDEX('}', @EmailAddress)=0
	AND CHARINDEX('?', @EmailAddress)=0
	AND CHARINDEX('<', @EmailAddress)=0
	AND CHARINDEX('>', @EmailAddress)=0
	AND CHARINDEX('=', @EmailAddress)=0
	AND CHARINDEX('~', @EmailAddress)=0
	AND CHARINDEX('`', @EmailAddress)=0	
	AND CHARINDEX('.', SUBSTRING(@EmailAddress, CHARINDEX('@', @EmailAddress)+1, 2))=0
	AND CHARINDEX('.', SUBSTRING(@EmailAddress, CHARINDEX('@', @EmailAddress)-1, 2))=0
	AND LEN(SUBSTRING(@EmailAddress, 0, CHARINDEX('@', @EmailAddress)))>1
	AND CHARINDEX('.', REVERSE(@EmailAddress)) > 2
	AND CHARINDEX('.', REVERSE(@EmailAddress)) < 5	
	THEN 1 ELSE  0 END

    
    RETURN @Result
END

Any suggestions are welcomed!

Solution 15 - Sql

DELETE 
FROM `contatti` 
WHERE `EMail` NOT LIKE "%.it" 
  AND `EMail` NOT LIKE "%.com" 
  AND `EMail` NOT LIKE "%.fr"  
  AND `EMail` NOT LIKE "%.net"  
  AND `EMail` NOT LIKE "%.ru"  
  AND `EMail` NOT LIKE "%.eu"  
  AND `EMail` NOT LIKE "%.org"  
  AND `EMail` NOT LIKE "%.edu"  
  AND `EMail` NOT LIKE "%.uk"  
  AND `EMail` NOT LIKE "%.de"  
  AND `EMail` NOT LIKE "%.biz"  
  AND `EMail` NOT LIKE "%.ch"  
  AND `EMail` NOT LIKE "%.bg"  
  AND `EMail` NOT LIKE "%.info"  
  AND `EMail` NOT LIKE "%.br"  
  AND `EMail` NOT LIKE "%.pt"  
  AND `EMail` NOT LIKE "%.za"  
  AND `EMail` NOT LIKE "%.vn"  
  AND `EMail` NOT LIKE "%.es"  
  AND `EMail` NOT LIKE "%.in"  
  AND `EMail` NOT LIKE "%.dk"  
  AND `EMail` NOT LIKE "%.ni"  
  AND `EMail` NOT LIKE "%.ar"

and put all extension you want

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