Question

邮件数据：

Mailid
-------------------------------
venkattaramanan1985@gmail.com
madanraj@gmail.com

预期输出

Name                 DomainName  Extension
-------------------  ----------  ---------
venkattaramanan1985  gmail       com
madanraj             gmail       com

Answer 1

它有一个简单的单行解决方案，假设电子邮件地址为 admin@system.org ，下面的查询将返回如上所述的部分：

SELECT 
--admin
LEFT(emailAddres, CHARINDEX('@', emailAddres) - 1) AS accountName  

--system.org
RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)) AS domainWithExtension

--system
LEFT(RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)), CHARINDEX('.', RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres))) - 1) AS domain

--org
RIGHT(RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)), LEN(RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres))) - CHARINDEX('.', RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)))) AS extension

希望得到这个帮助。

Answer 2

首先，为什么使用SQL服务器？

我建议使用客户端进行字符串操作，然后让SQL服务器返回数据。这应该是SQL服务器的唯一工作。

如果你真的必须使用SQL服务器，你可能想要事先阅读SQL中的split字符串。（性能比较阅读here）

对于以下提出的解决方案，您需要一个table-value-function来拆分带有指定分隔符的传递字符串，该分隔符返回有序的子字符串。我修改了从here获取的公用表表达式以返回排序。

CREATE FUNCTION dbo.SplitStrings_CTE
(
   @List       NVARCHAR(MAX),
   @Delimiter  NVARCHAR(255)
)
RETURNS @Items TABLE ([Order] INT IDENTITY(1,1) NOT NULL, [Item] NVARCHAR(4000))
WITH SCHEMABINDING
AS
BEGIN
    --same as the original here, the ordering is inserted automatically by IDENTITY
    (...)
END

现在我添加了一个函数来重新分割电子邮件字符串，重新使用上面的函数：

CREATE FUNCTION dbo.SplitEmail
(
   @email NVARCHAR(254)
)
RETURNS @splitted TABLE (
    [Email] NVARCHAR(254),
    [Name] NVARCHAR(254),
    [DomainName] NVARCHAR(254),
    [Extension] NVARCHAR(254)
)
WITH SCHEMABINDING
AS
BEGIN
    DECLARE @name NVARCHAR(254), @domain NVARCHAR(254), @ext NVARCHAR(254)
    --init the email parts with defaults
    SELECT @name = ISNULL(@email, ''), @domain = '', @ext = '';
    --we only want to split @email if at least one '@' is found in it
    IF (@email IS NOT NULL AND LEN(@email) <> 0 AND CHARINDEX('@', @email) <> 0) BEGIN
        --take the last occuring substring from @email as the @domain
        SELECT TOP 1 @domain = [Item]
        FROM [dbo].[SplitStrings_CTE](@name, '@')
        ORDER BY [Order] DESC
        --@email without @domain + '@' is the @name
        SET @name = LEFT(@name, LEN(@name) - LEN(@domain) - 1)
        --we only want to split @domain if at least one '.' is found in it
        IF (CHARINDEX('.', @domain) <> 0) BEGIN
            --take the last occuring substring from @domain as the @ext
            SELECT TOP 1 @ext = [Item]
            FROM [dbo].[SplitStrings_CTE](@domain, '.')
            ORDER BY [Order] DESC
            --split the @ext from the @domain
            SET @domain = LEFT(@domain, LEN(@domain) - LEN(@ext) - 1)
        END
        ELSE BEGIN
            SET @ext = @domain
            SET @domain = ''
        END
    END
    INSERT INTO @splitted ([Email], [Name], [DomainName], [Extension])
    VALUES (@email, @name, @domain, @ext)
    RETURN
END

调用该函数 - 例如：

DECLARE @@samples TABLE([mailid] NVARCHAR(255))

INSERT INTO @@samples ([mailid]) VALUES ('venkattaramanan1985@gmail.com')
INSERT INTO @@samples ([mailid]) VALUES ('madanraj@gmail.com')
INSERT INTO @@samples ([mailid]) VALUES ('madanraj@sub.gmail.com')
INSERT INTO @@samples ([mailid]) VALUES ('sm@al.l')
INSERT INTO @@samples ([mailid]) VALUES ('is@sane.')
INSERT INTO @@samples ([mailid]) VALUES ('is@sane')
INSERT INTO @@samples ([mailid]) VALUES ('rubbish@h.h.h.h.h')
INSERT INTO @@samples ([mailid]) VALUES (NULL)
INSERT INTO @@samples ([mailid]) VALUES ('')
INSERT INTO @@samples ([mailid]) VALUES ('invalid')
INSERT INTO @@samples ([mailid]) VALUES ('@@@@@@@@@...')

SELECT e.*
FROM @@samples AS s
CROSS APPLY dbo.SplitEmail(s.mailid) AS e

将返回此结果：

Email                              Name                    DomainName        Extension
---------------------------------  ----------------------  ----------------  ------------
venkattaramanan1985@gmail.com      venkattaramanan1985     gmail             com
madanraj@gmail.com                 madanraj                gmail             com
madanraj@sub.gmail.com             madanraj                sub.gmail         com
sm@al.l                            sm                      al                l
is@sane.                           is                                        sane
is@sane                            is                                        sane
rubbish@h.h.h.h.h                  rubbish                 h.h.h.h           h
NULL                                                                         

invalid                            invalid                                   
@@@@@@@@@...                       @@@@@@@@                ..

Answer 3

declare @var varchar(50) ='Abc.xyz@rediffmail.com';
select 
SUBSTRING(@var,0,charindex('@',@var)) as UserName
,
Substring(@var,charindex('@',@var)+1,charindex('.',@var,charindex('@',@var,0))-(charindex('@',@var)+1)) as DomainName
,
substring(@var,charindex('.',@var,charindex('@',@var))+1,len(@var)) as Ext

Answer 4

我看到 OP 将请求标记为 sql-server。我发现这个在找mysql，去图。所以这是一个mysql答案。

SUBSTRING_INDEX('john.doe@simon.says.com', '@', 1) AS Name,
SUBSTRING_INDEX(SUBSTRING_INDEX('john.doe@simon.says.com', '@', -1), '.', ROUND((LENGTH(SUBSTRING_INDEX('john.doe@simon.says.com', '@', -1)) - LENGTH(REPLACE(SUBSTRING_INDEX('john.doe@simon.says.com', '@', -1), '.', ''))) / LENGTH('.'))) AS DomainName,
SUBSTRING_INDEX('john.doe@simon.says.com', '.', -1) AS Extension,

最终结果将返回：

姓名：john.doe
域名：simon.says
扩展名：com

如何将电子邮件地址拆分为其部分

4 个答案: