Question

我在包含电子邮件地址的表格中有一个自由格式的文本字段。问题是该字段中有很多其他信息，在电子邮件地址之前和之后。编辑：以下是该字段可能的示例：

Address: 123 Anystreet. Customer requires xyz. Email: person@example.com Other random info...

我认为尝试仅提取电子邮件地址的最佳方法是对@字符进行SQL搜索，并检索所有周围文本，直到找到空格。这可能吗？或者有更好的方法吗？

Answer 1

这是一种方法

SELECT Email = Reverse(Substring(Reverse(string), revpos+1, Charindex(' ', Reverse(string), revpos)-revpos))
               + Substring(string, pos, Charindex(' ', string, pos)-pos)
FROM   yourtable
       CROSS apply(VALUES (Charindex('@', string)))tc(pos)
       CROSS apply(VALUES (Charindex('@', Reverse(string))))tc1(revpos)

注意：

这假设有两件事

始终只有一个@出现
Email总是被空格包围

Rextester Demo

Answer 2

基于答案at former question（2015年4月13日2:44由Stephan撰写）请参阅此SQL Fiddle

CREATE TABLE Table1
    ([BigString] varchar(100))
;

INSERT INTO Table1
    ([BigString])
VALUES
    ('Address: 123 Anystreet. Customer requires xyz. Email: person@example.com Other random info...'),
    ('blah MyEmailAddress@domain.org'),
    ('blah MyEmailAddress@domain.org blah blah'),
    ('MyEmailAddress@domain.org blah'),
    ('no email')
;

查询1 ：

select BigString, c3.email
from (
    select BigString
    from Table1
    where CHARINDEX('@',BigString) > 0
    ) t
cross apply (select charindex('@',BigString)) c1 (atpos)
cross apply (select charindex(' ',BigString + ' ',c1.atpos), reverse(substring(BigString,1,c1.atpos))
            ) c2 (endOfEmail,RevString)  
cross apply (select RTRIM(Reverse(left(RevString,charindex(' ',RevString+' ')-1))
                  + substring(BigString,c1.atpos+1,endOfEmail-c1.atpos))
            ) c3 (email)

<强> Results ：

|                                                                                     BigString |                     email |
|-----------------------------------------------------------------------------------------------|---------------------------|
| Address: 123 Anystreet. Customer requires xyz. Email: person@example.com Other random info... |        person@example.com |
|                                                                blah MyEmailAddress@domain.org | MyEmailAddress@domain.org |
|                                                      blah MyEmailAddress@domain.org blah blah | MyEmailAddress@domain.org |
|                                                                MyEmailAddress@domain.org blah | MyEmailAddress@domain.org |

返回特定字符周围的文字

2 个答案:

Rextester Demo