Question

美好的一天，

我为此工作了一个小时，我想在特定列中提取特定单词

这是我的SQL查询

 DECLARE @string_of_text NVARCHAR(MAX)='This is sample text that will retrieve all text with CVE-2014-1775, CVE-2014-1779, CVE-2014-1799, CVE-2014-1803, and CVE-2014-2757.' 

    DECLARE @get_str NVARCHAR(MAX)=''
    DECLARE @flag INT=1
    DECLARE @move INT=1 
       WHILE  PATINDEX('%CVE-%', SUBSTRING(@string_of_text 
             ,@move,LEN(@string_of_text )))>0
 BEGIN

  SET @str=SUBSTRING(@string_of_text ,@move,LEN(@string_of_text ))
  SET @flag= PATINDEX('%CVE-%', @string_of_text )
  SET @get_str = @get_str +','+SUBSTRING(@string_of_text , @flag,13)
  SET @move=@flag+13
  END
  SELECT STUFF(@get_str ,1,1,'') 'CVE LIST'

样本结果

CVE列表 CVE-2014-1775，CVE-2014-1779，CVE-2014-1799，CVE-2014-1803，CVE-2014-2757

Answer 1

该要求有点含糊，但是，如果您尝试将字符串中存在的一个或多个单词提取到结果集中，则可以使用NGrams8K。请注意以下示例：

DECLARE 
  @string VARCHAR(8000) = 'This dog barked at that dog then there were two barking dogs', 
  @searchText VARCHAR(8000) = 'dog';

SELECT ng.position, ng.token
FROM dbo.ngrams8k(@string, LEN(@searchText)) ng
WHERE ng.token = @searchText;

返回：

position     token
------------ --------
6            dog
25           dog
57           dog

要对表使用此逻辑，可以执行以下操作：

DECLARE @table TABLE (someId INT IDENTITY, someText VARCHAR(8000));
INSERT @table (someText)
VALUES ('this fish, that fish...'), ('more text containing the word "fish"'),('nothing');

DECLARE @searchText VARCHAR(8000) = 'Fish';

SELECT t.someId, t.someText, ng.position, ng.token
FROM @table t
CROSS APPLY dbo.ngrams8k(t.someText, LEN(@searchText)) ng
WHERE ng.token = @searchText;

返回：

someId   someText                               position  token
-------- -------------------------------------- --------- ---------
1        this fish, that fish...                6         fish
1        this fish, that fish...                17        fish
2        more text containing the word "fish"   32        fish

提取列中的特定单词

1 个答案: