如何从 SQL Server 列中的 html 获取数据

Question

我在 SQL Server 列中有一些 html 内容，我想从 html 中读取内容。

例如：

<ektdesignns_choices ektdesignns_nodetype="element" title="How many gigs do you play each month?" ektdesignns_caption="How many gigs do you play each month?" name="ektpoll1303074024421" ektdesignns_name="ektpoll1303074024421" id="ektpoll1303074024421">
  <ol contenteditable="false" onkeypress="design_validate_choice(1, -1, this, 'Options are required.')" onclick="design_validate_choice(1, -1, this, 'Options are required.')" onblur="design_validate_choice(1, -1, this, 'Options are required.')" ektdesignns_validation="choice-req" ektdesignns_maxoccurs="1" ektdesignns_minoccurs="1" unselectable="on" title="How many gigs do you play each month?" class="design_list_vertical">
    <li>
      <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="1 or fewer_1" title="1 or fewer" id="ID2504263" />
      <label contenteditable="true" unselectable="off" for="ID2504263">1 or fewer</label>
    </li>
    <li>
       <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="2-4_2" title="2-4" id="ID5115606" />
       <label contenteditable="true" unselectable="off" for="ID5115606">2-4</label>
    </li>
    <li>
        <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="5-7_3" title="5-7" id="ID477116" />
        <label contenteditable="true" unselectable="off" for="ID477116">5-7</label>
    </li>
    <li>
        <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="8 or more_4" title="8 or more" id="ID5515606" />
        <label contenteditable="true" unselectable="off" for="ID5515606">8 or more</label>
    </li>
  </ol>
</ektdesignns_choices><input type="submit" value="Vote" />

我想阅读这个 html 中的所有标签。有人有什么想法，我该怎么做？

Answer 1

如果您的 HTML 确实符合 XHTML，并且您的 HTML 存储在 SQL Server 表的 XML 列中，那么您可以使用 XQuery 在 T-SQL 中检索标签：

DECLARE @HtmlTbl TABLE (ID INT IDENTITY, Html XML)

INSERT INTO @HtmlTbl(Html) VALUES('<ektdesignns_choices ektdesignns_nodetype="element" title="How many gigs do you play each month?" ektdesignns_caption="How many gigs do you play each month?" name="ektpoll1303074024421" ektdesignns_name="ektpoll1303074024421" id="ektpoll1303074024421">
  <ol contenteditable="false" onkeypress="design_validate_choice(1, -1, this, ''Options are required.'')" onclick="design_validate_choice(1, -1, this, ''Options are required.'')" onblur="design_validate_choice(1, -1, this, ''Options are required.'')" ektdesignns_validation="choice-req" ektdesignns_maxoccurs="1" ektdesignns_minoccurs="1" unselectable="on" title="How many gigs do you play each month?" class="design_list_vertical">
    <li>
      <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="1 or fewer_1" title="1 or fewer" id="ID2504263" />
      <label contenteditable="true" unselectable="off" for="ID2504263">1 or fewer</label>
    </li>
    <li>
       <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="2-4_2" title="2-4" id="ID5115606" />
       <label contenteditable="true" unselectable="off" for="ID5115606">2-4</label>
    </li>
    <li>
        <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="5-7_3" title="5-7" id="ID477116" />
        <label contenteditable="true" unselectable="off" for="ID477116">5-7</label>
    </li>
    <li>
        <input type="radio" ektdesignns_nodetype="item" name="ektpoll1303074024421" value="8 or more_4" title="8 or more" id="ID5515606" />
        <label contenteditable="true" unselectable="off" for="ID5515606">8 or more</label>
    </li>
  </ol></ektdesignns_choices><input type="submit" value="Vote" />')

这将从您的 (X)Html 中检索所有 <label> 元素作为单个 XML 字符串：

SELECT
    Html.query('//label')
FROM @HtmlTbl 
WHERE ID = 1

输出：

<label contenteditable="true" unselectable="off" for="ID2504263">1 or fewer</label>
<label contenteditable="true" unselectable="off" for="ID5115606">2-4</label>
<label contenteditable="true" unselectable="off" for="ID477116">5-7</label>
<label contenteditable="true" unselectable="off" for="ID5515606">8 or more</label>

或者这将选择<label>标签的所有内容，每行一个：

SELECT
    C.value('(.)[1]', 'varchar(1000)')
FROM @HtmlTbl 
CROSS APPLY Html.nodes('//label') AS T(C)
WHERE ID = 1

输出：

1 or fewer
2-4
5-7
8 or more

Answer 2

从数据库中提取数据，然后使用 HTML 解析器提取您想要的信息。它会让你的生活更加更轻松。

无论您做什么，请不要尝试使用正则表达式，除非您只是在寻找与正则表达式匹配的数据。 （由于 HTML 不是一门常规语言，它带来的问题往往多于解决的问题）

Answer 3

如果你拥有的所有 HTML 都和这个一样，你可以将它转换为 XML 并使用一些 XQuery 来查找标签节点，

select T.N.value('.', 'nvarchar(100)')
from Table
    cross apply XMLCol.nodes('//label') as T(N)

Answer 4

如果要从定义明确的标签中提取值，可以使用 PATINDEX 和 SUBSTRING

 /*
    <HTML><head><meta name='viewport' content='width=device-width, initial-scale=1.0'>
    </head>
    <BODY onload='document.frmLaunch.submit();'> Redirecting... 
    <FORM name='frmLaunch' method='POST' action='https://acsabsatest.bankserv.co.za/mdpayacs/pareq'>
    <input type=hidden name='PaReq' value='eJxVUctuwjAQ/JWID8jaJjy1tRRKJXKg4iWQuLnOtkSUJDgJ0H597ZCU9pSZ2ex4dxY3B0M0XZOuDEmcU1GoD/KS+KmzWC1HnHWDHu9IXIQrOku8kCmSLJXcZ75AaKntM/qg0lKi0udJ9Co55wgNxhOZaCq56CLcIabqRHKi0mNB5hK+m0Qrr/VAqKuosyotzZcccIbQEqzMpzyUZV6MAa7Xq//WmPg6878VgqsjPOZZVA4V1u+WxHK3iWfrlzlf87lYH6NgyfP9bhvddtvwCcH9gbEqSQrGRywQgceGYz4aswCh1lGd3CByH6484TM7WCNg7t4J70S4wl8BbbqGUt0u0zKkW56l5FoQfjHGVGi7RPN5bPA8c/nq0iY47AeDXn9Qh1wLziqxAQnOerWXIwiuBZrjQXNdi/5d/Qf60asq'>
    <input type=hidden name='TermUrl' value='http://TermUrl'>
    <input type=hidden name='MD' value='469695'></FORM></BODY></HTML>
    */
--Find the start of the tag
    SELECT PATINDEX('%<input type=hidden name=''PaReq'' value=%', @webViewData); 
--(Answer is 246)
-->Find the end of the tag
    SELECT PATINDEX('%''>%', substring(@webViewData,PATINDEX('%<input type=hidden name=''PaReq'' value=%', @webViewData),len(@webViewData))); 
--(Answer is 468)
--Get the value content of the tag
    select substring(@webViewData,246+39,468-40)
--Everything combined:
    select substring(@webViewData,PATINDEX('%<input type=hidden name=''PaReq'' value=%', @webViewData)+39,PATINDEX('%''>%', substring(@webViewData,PATINDEX('%<input type=hidden name=''PaReq'' value=%', @webViewData),len(@webViewData)))-40)