TSQL电子邮件验证(不带regex)

非常 基本是:

SELECT
  EmailAddress, 
  CASE WHEN EmailAddress LIKE '%_@_%_.__%' 
            AND EmailAddress NOT LIKE '%[any obviously invalid characters]%' 
  THEN 'Could be' 
  ELSE 'Nope' 
  END Validates
FROM 
  Table

这与中间的@匹配,前面至少有一个字符,后面至少有两个字符,一个点,TLD至少有两个字符。

你可以写更多 LIKE 模式可以做更具体的事情,但是你永远无法匹配所有可能是电子邮件地址的东西,同时又不让那些没有的东西溜走。即使使用正则表达式,您也很难正确地执行它。此外,即使根据RFC的字母进行匹配,也会匹配大多数电子邮件系统不会接受/使用的地址构造。

无论如何,在数据库级别执行此操作可能是错误的方法,因此如上所述的基本健全性检查可能是获得性能方面最好的方法,并且在应用程序中执行此操作将为您提供更大的灵活性。

这里有一个更详细的示例函数,我不记得是从哪里得到的(几年前),或者如果我修改了它,否则我将包括适当的属性:

CREATE FUNCTION [dbo].[fnAppEmailCheck](@email VARCHAR(255))   
--Returns true if the string is a valid email address.  
RETURNS bit  
as  
BEGIN  
     DECLARE @valid bit  
     IF @email IS NOT NULL   
          SET @email = LOWER(@email)  
          SET @valid = 0  
          IF @email like '[a-z,0-9,_,-]%@[a-z,0-9,_,-]%.[a-z][a-z]%'  
             AND LEN(@email) = LEN(dbo.fnAppStripNonEmail(@email))  
             AND @email NOT like '%@%@%'  
             AND CHARINDEX('.@',@email) = 0  
             AND CHARINDEX('..',@email) = 0  
             AND CHARINDEX(',',@email) = 0  
             AND RIGHT(@email,1) between 'a' AND 'z'  
               SET @valid=1  
     RETURN @valid  
END  

答案很好!基于这些建议,我提出了一个结合最佳2个答案的简化函数。

CREATE FUNCTION [dbo].[fnIsValidEmail]
(
    @email varchar(255)
)   
--Returns true if the string is a valid email address.  
RETURNS bit  
As  
BEGIN
    RETURN CASE WHEN ISNULL(@email, '') <> '' AND @email LIKE '%_@%_.__%' THEN 1 ELSE 0 END
END

fnappstripnonemail在score下丢失,需要将其添加到keep值中

Create Function [dbo].[fnAppStripNonEmail](@Temp VarChar(1000))
Returns VarChar(1000)
AS
Begin

    Declare @KeepValues as varchar(50)
    Set @KeepValues = '%[^a-z,0-9,_,@,.,-]%'
    While PatIndex(@KeepValues, @Temp) > 0
        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '')

    Return @Temp
End

Create Function [dbo].[fnAppStripNonEmail](@Temp VarChar(1000))
Returns VarChar(1000)
AS
Begin

    Declare @KeepValues as varchar(50)
    Set @KeepValues = '%[^a-z,0-9,@,.,-]%'
    While PatIndex(@KeepValues, @Temp) > 0
        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '')

    Return @Temp
End

这是选择它们的最简单方法。

使用此查询

SELECT * FROM <TableName> WHERE [EMail] NOT LIKE '%_@__%.__%'

CREATE FUNCTION fnIsValidEmail
(
    @email varchar(255)
)
RETURNS bit
AS
BEGIN

    DECLARE @IsValidEmail bit = 0

    IF (@email not like '%[^a-z,0-9,@,.,!,#,$,%%,&,'',*,+,--,/,=,?,^,_,`,{,|,},~]%' --First Carat ^ means Not these characters in the LIKE clause. The list is the valid email characters.
        AND @email like '%_@_%_.[a-z,0-9][a-z]%'
        AND @email NOT like '%@%@%'  
        AND @email NOT like '%..%'
        AND @email NOT like '.%'
        AND @email NOT like '%.'
        AND CHARINDEX('@', @email) <= 65
        )
    BEGIN
        SET @IsValidEmail = 1
    END

    RETURN @IsValidEmail

END

在SQL 2016或+

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

从托马拉克的书里

select 1
where @email not like '%[^a-z,0-9,@,.]%'
and @email like '%_@_%_.__%'