如何比较两个用逗号分隔的列值? [英] How to compare two column values which are comma separated values?

问题描述

我有一个带有特定列的表，其中有一列包含逗号分隔的值，例如 test，exam，result，other .

I have one table with specific columns, in that there is a column which contains comma separated values like test,exam,result,other.

我将诸如 result，sample，unknown，extras 之类的字符串作为参数传递给存储过程.然后我想通过检查此字符串中的每个短语来获取相关记录.

I will pass a string like result,sample,unknown,extras as a parameter to the stored procedure. and then I want to get the related records by checking each and every phrase in this string.

例如:

表A

ID        Name                Words
1         samson              test,exam,result,other
2         john                sample,no query
3         smith               tester,SE

现在我要搜索结果，样品，未知，其他

那么结果应该是

ID        Name                Words
1         samson              test,exam,result,other
2         john                sample,no query

因为第一条记录结果匹配，第二条记录 sample 匹配.

because in the first record result matched and in the second record sample matched.

推荐答案

这不是一个很好的设计.最好将Word拆分成一个单独的表(id，word).

That's not a great design, you know. Better to split Words off into a separate table (id, word).

也就是说，这应该可以解决问题:

That said, this should do the trick:

set nocount on
declare @words varchar(max) = 'result,sample,unknown,extras'

declare @split table (word varchar(64))
declare @word varchar(64), @start int, @end int, @stop int

-- string split in 8 lines
select @words += ',', @start = 1, @stop = len(@words)+1
while @start < @stop begin
  select
    @end   = charindex(',',@words,@start)
  , @word  = rtrim(ltrim(substring(@words,@start,@end-@start)))
  , @start = @end+1
  insert @split values (@word)
end

select * from TableA a
where exists (
  select * from @split w
  where charindex(','+w.word+',',','+a.words+',') > 0
  )

我可以为您提供这个功能而在DBA地狱中燃烧吗！

May I burn in DBA hell for providing you this!

替换了带有SUBSTRING切片的STUFF，在长列表上快了一个数量级.

replaced STUFF w/ SUBSTRING slicing, an order of magnitude faster on long lists.

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