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Question

我有一张表格如下：

TABLE1

No  Description
1   Hello Hai Hello
2   Good Bad Good
3   Hello Good Hai
4   Hai Hello Bad
5   Hello Hello Hello

现在，如果我运行以下查询：

Select * 
from TABLE1 
where Description like '%Hai%' 
   OR  Description like '%Hello%' 
   OR Description like '%Good%'

我希望结果如下（通过添加一个额外的列“FIRST MATCHED WORD”）：

No  Description     First Matched Word
1   Hello Hai Hello     Hai
2   Good Bad Good       Good
3   Hello Good Hai      Hai
4   Hai Hello Bad       Hai
5   Hello Hello Hello   Hello

听到我的意图是找出第一个匹配的单词取决于我们的查询。请帮助我。

Answer 1

您可以通过以下方式在CASE statement查询中使用SELECT：

Select No,Description, 
  CASE 
      WHEN Description like '%Hai%' THEN 'Hai' 
      WHEN Description like '%Hello%' THEN 'Hello'
      WHEN Description like '%Good%' THEN 'Good'
   END 
from TABLE1 
where Description like '%Hai%' 
   OR  Description like '%Hello%' 
   OR Description like '%Good%'

请参阅SQLFIDDLE

Case Statement返回计算结果为TRUE的第一个布尔表达式的结果。

Answer 2

试试这个：

如果要添加更多匹配的单词，只需将该单词添加到具有排名的优先级表中即可。如果要匹配大量单词，可以将优先级表作为永久表

with precedence as(
select 1 rnk, 'Hai' as word union all
select 2 rnk, 'Hello' union all
select 3 rnk, 'Good' ),
cte as 
    (select * 
     from Table1
     join precedence
     on  [Description] like '%'+word+'%' ),
cte1 as(select [No],[Description],word,
               ROW_NUMBER() over (partition by [No] order by rnk) as row_num 
        from cte)
select [No],[Description],word from cte1 where row_num=1

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Answer 3

试试这个：

select *,'Hai' as 'First Matched Word' from Table1 where [Description] like '%Hai%'
union
select *,'Hello' as 'First Matched Word' from Table1 where [Description] like '%hello%' 
and [No] not in(select [No] from Table1 where [Description] like '%Hai%')
union
select *,'Good' as 'First Matched Word' from Table1 where [Description] like '%Good%' 
and [No] not in(select [No] from Table1 where [Description] like '%hello%' 
or [Description] like '%Hai%'
);

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Answer 4

试试这个：

;WITH CTE AS
(
    SELECT
      t1.No,
      t1.Description, 
      t2.Description AS matched,
      ROW_NUMBER() OVER(PARTITION BY t1.DESCRIPTION 
                            ORDER BY t1.DESCRIPTION) row_num
    FROM @TABLE1 t1
    INNER JOIN
    (
        SELECT Description = 'Hai'
        UNION ALL 
        SELECT 'Hello'
        UNION ALL
        SELECT 'Good'
    ) t2 ON t1.Description LIKE '%' + t2.Description + '%'
)
SELECT 
  No,
  Description,
  matched AS 'first matched word'
FROM CTE
WHERE row_num = 1
ORDER BY no;

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Answer 5

如果是这种情况，你可以选择if else语句，如下所示

if exists(select * from Table1 where description like '%Hai%')
begin
     update table1 set FirstMatchedWord = 'Hai' where No = @No
end
else
begin
     if exists(select * from Table1 where description like '%Hello%')
     begin
         update table1 set FirstMatchedWord = 'Hello' where No = @No
     end
     else
     begin
         if exists(select * from Table1 where description like '%Good%')
         begin
             update table1 set FirstMatchedWord = 'Good' where No = @No
         end
     end
end

希望这会有所帮助：D

在SQL Server的列中查找第一个匹配的字符串

5 个答案:

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