CREATE FUNCTION [dbo].[fnSplit] ( @sep CHAR(1), @str VARCHAR(512) )
RETURNS TABLE AS
RETURN (
WITH Pieces(pn, start, stop) AS (
SELECT 1, 1, CHARINDEX(@sep, @str)
UNION ALL
SELECT pn + 1, stop + 1, CHARINDEX(@sep, @str, stop + 1)
FROM Pieces
WHERE stop > 0
)
SELECT
pn AS Id,
SUBSTRING(@str, start, CASE WHEN stop > 0 THEN stop - start ELSE 512 END) AS Data
FROM
Pieces
)
查询
DECLARE @FilterTable TABLE (Data VARCHAR(512))
INSERT INTO @FilterTable (Data)
SELECT DISTINCT S.Data
FROM fnSplit(' ', 'word1 word2 word3') S -- Contains words
SELECT DISTINCT
T.*
FROM
MyTable T
INNER JOIN @FilterTable F1 ON T.Column1 LIKE '%' + F1.Data + '%'
LEFT JOIN @FilterTable F2 ON T.Column1 NOT LIKE '%' + F2.Data + '%'
WHERE
F2.Data IS NULL
606
而不是 SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 word2 word3' ,在这些单词之间添加And,如:
SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 And word2 And word3'
-- table to search in
CREATE TABLE dbo.myTable
(
myTableId int NOT NULL IDENTITY (1, 1),
code varchar(200) NOT NULL,
description varchar(200) NOT NULL -- this column contains the values we are going to search in
) ON [PRIMARY]
GO
-- function to split space separated search string into individual words
CREATE FUNCTION [dbo].[fnSplit] (@StringInput nvarchar(max),
@Delimiter nvarchar(1))
RETURNS @OutputTable TABLE (
id nvarchar(1000)
)
AS
BEGIN
DECLARE @String nvarchar(100);
WHILE LEN(@StringInput) > 0
BEGIN
SET @String = LEFT(@StringInput, ISNULL(NULLIF(CHARINDEX(@Delimiter, @StringInput) - 1, -1),
LEN(@StringInput)));
SET @StringInput = SUBSTRING(@StringInput, ISNULL(NULLIF(CHARINDEX
(
@Delimiter, @StringInput
),
0
), LEN
(
@StringInput)
)
+ 1, LEN(@StringInput));
INSERT INTO @OutputTable (id)
VALUES (@String);
END;
RETURN;
END;
GO
-- this is the search script which can be optionally converted to a stored procedure /function
declare @search varchar(max) = 'infection upper acute genito'; -- enter your search string here
-- the searched string above should give rows containing the following
-- infection in upper side with acute genitointestinal tract
-- acute infection in upper teeth
-- acute genitointestinal pain
if (len(trim(@search)) = 0) -- if search string is empty, just return records ordered alphabetically
begin
select 1 as Priority ,myTableid, code, Description from myTable order by Description
return;
end
declare @splitTable Table(
wordRank int Identity(1,1), -- individual words are assinged priority order (in order of occurence/position)
word varchar(200)
)
declare @nonWordTable Table( -- table to trim out auxiliary verbs, prepositions etc. from the search
id varchar(200)
)
insert into @nonWordTable values
('of'),
('with'),
('at'),
('in'),
('for'),
('on'),
('by'),
('like'),
('up'),
('off'),
('near'),
('is'),
('are'),
(','),
(':'),
(';')
insert into @splitTable
select id from dbo.fnSplit(@search,' '); -- this function gives you a table with rows containing all the space separated words of the search like in this e.g., the output will be -
-- id
-------------
-- infection
-- upper
-- acute
-- genito
delete s from @splitTable s join @nonWordTable n on s.word = n.id; -- trimming out non-words here
declare @countOfSearchStrings int = (select count(word) from @splitTable); -- count of space separated words for search
declare @highestPriority int = POWER(@countOfSearchStrings,3);
with plainMatches as
(
select myTableid, @highestPriority as Priority from myTable where Description like @search -- exact matches have highest priority
union
select myTableid, @highestPriority-1 as Priority from myTable where Description like @search + '%' -- then with something at the end
union
select myTableid, @highestPriority-2 as Priority from myTable where Description like '%' + @search -- then with something at the beginning
union
select myTableid, @highestPriority-3 as Priority from myTable where Description like '%' + @search + '%' -- then if the word falls somewhere in between
),
splitWordMatches as( -- give each searched word a rank based on its position in the searched string
-- and calculate its char index in the field to search
select myTable.myTableid, (@countOfSearchStrings - s.wordRank) as Priority, s.word,
wordIndex = CHARINDEX(s.word, myTable.Description) from myTable join @splitTable s on myTable.Description like '%'+ s.word + '%'
-- and not exists(select myTableid from plainMatches p where p.myTableId = myTable.myTableId) -- need not look into myTables that have already been found in plainmatches as they are highest ranked
-- this one takes a long time though, so commenting it, will have no impact on the result
),
matchingRowsWithAllWords as (
select myTableid, count(myTableid) as myTableCount from splitWordMatches group by(myTableid) having count(myTableid) = @countOfSearchStrings
)
, -- trim off the CTE here if you don't care about the ordering of words to be considered for priority
wordIndexRatings as( -- reverse the char indexes retrived above so that words occuring earlier have higher weightage
-- and then normalize them to sequential values
select s.myTableid, Priority, word, ROW_NUMBER() over (partition by s.myTableid order by wordindex desc) as comparativeWordIndex
from splitWordMatches s join matchingRowsWithAllWords m on s.myTableId = m.myTableId
)
,
wordIndexSequenceRatings as ( -- need to do this to ensure that if the same set of words from search string is found in two rows,
-- their sequence in the field value is taken into account for higher priority
select w.myTableid, w.word, (w.Priority + w.comparativeWordIndex + coalesce(sequncedPriority ,0)) as Priority
from wordIndexRatings w left join
(
select w1.myTableid, w1.priority, w1.word, w1.comparativeWordIndex, count(w1.myTableid) as sequncedPriority
from wordIndexRatings w1 join wordIndexRatings w2 on w1.myTableId = w2.myTableId and w1.Priority > w2.Priority and w1.comparativeWordIndex>w2.comparativeWordIndex
group by w1.myTableid, w1.priority,w1.word, w1.comparativeWordIndex
)
sequencedPriority on w.myTableId = sequencedPriority.myTableId and w.Priority = sequencedPriority.Priority
),
prioritizedSplitWordMatches as ( -- this calculates the cumulative priority for a field value
select w1.myTableId, sum(w1.Priority) as OverallPriority from wordIndexSequenceRatings w1 join wordIndexSequenceRatings w2 on w1.myTableId = w2.myTableId
where w1.word <> w2.word group by w1.myTableid
),
completeSet as (
select myTableid, priority from plainMatches -- get plain matches which should be highest ranked
union
select myTableid, OverallPriority as priority from prioritizedSplitWordMatches -- get ranked split word matches (which are ordered based on word rank in search string and sequence)
),
maximizedCompleteSet as( -- set the priority of a field value = maximum priority for that field value
select myTableid, max(priority) as Priority from completeSet group by myTableId
)
select priority, myTable.myTableid , code, Description from maximizedCompleteSet m join myTable on m.myTableId = myTable.myTableId
order by Priority desc, Description -- order by priority desc to get highest rated items on top
--offset 0 rows fetch next 50 rows only -- optional paging
16
为什么不用“in”代替呢?
Select *
from table
where columnname in (word1, word2, word3)
0
DECLARE @SearchStr nvarchar(100)
SET @SearchStr = ' '
CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630))
SET NOCOUNT ON
DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')
WHILE @TableName IS NOT NULL
BEGIN
SET @ColumnName = ''
SET @TableName =
(
SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE'
AND QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
AND OBJECTPROPERTY(
OBJECT_ID(
QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
), 'IsMSShipped'
) = 0
)
WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)
BEGIN
SET @ColumnName =
(
SELECT MIN(QUOTENAME(COLUMN_NAME))
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = PARSENAME(@TableName, 2)
AND TABLE_NAME = PARSENAME(@TableName, 1)
AND DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal')
AND QUOTENAME(COLUMN_NAME) > @ColumnName
)
IF @ColumnName IS NOT NULL
BEGIN
INSERT INTO #Results
EXEC
(
'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT(' + @ColumnName + ', 3630) FROM ' + @TableName + ' (NOLOCK) ' +
' WHERE ' + @ColumnName + ' LIKE ' + @SearchStr2
)
END
END
END
SELECT ColumnName, ColumnValue FROM #Results
DROP TABLE #Results
-1
select * from table where name regexp '^word[1-3]$'
要么
select * from table where name in ('word1','word2','word3')
15 回答
这将显示
column1
的部分值包含word
的所有记录 .尝试在MS SQL Server中的全文索引中使用“tesarus搜索” . 如果您有数百万条记录,这比在搜索中使用“%”要好得多 . tesarus的内存消耗量比其他内存少 . 尝试搜索这个功能:)
最好的方法是在表中的列上创建全文索引,并使用contains而不是LIKE
相当慢,但工作方法包括 any 的单词:
如果您需要 all 个词,请使用:
如果你想要更快的东西,你需要查看全文搜索,这对每种数据库类型都是非常具体的 .
请注意,如果使用
LIKE
来确定字符串是否是另一个字符串的子字符串,则必须转义搜索字符串中的模式匹配字符 .如果您的SQL方言支持
CHARINDEX
,则使用它会更容易:此外,请记住,这和接受的答案中的方法仅涵盖子字符串匹配而不是字匹配 . 因此,例如,字符串
'word1word2word3'
仍然匹配 .功能
查询
而不是
SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 word2 word3'
,在这些单词之间添加And,如:有关详细信息,请参见此处https://msdn.microsoft.com/en-us/library/ms187787.aspx
UPDATE
要选择短语,请使用双引号,如:
p.s. 在使用contains关键字之前,您必须先在表上启用全文搜索 . 有关详细信息,请参阅此处https://docs.microsoft.com/en-us/sql/relational-databases/search/get-started-with-full-text-search
根据编辑问题将
OR
更改为AND
.如果您使用的是 Oracle Database ,则可以使用contains查询来实现此目的 . 包含查询比查询更快 .
如果你需要所有的话
如果你需要任何一个词
包含列上 CONTEXT 类型的需要索引 .
如果你只是想找到一个匹配 .
SQL Server:
要获得完全匹配 . 示例
(';a;ab;ac;',';b;')
将无法匹配 .实现问题中提到的内容的最简单方法之一是使用带有NEAR或'~'的CONTAINS . 例如,以下查询将为我们提供具体包含word1,word2和word3的所有列 .
另外,CONTAINSTABLE基于“word1”,“word2”和“word3”的接近度返回每个文档的等级 . 例如,如果文档包含句子“word1是word2和word3”,则其排名会很高,因为这些术语比其他文档更接近彼此 .
我想补充的另一件事是我们也可以使用proximity_term来查找列在列短语内的特定距离内的列 .
理想情况下,如果使用sql server全文搜索,这应该完成 . 但是,如果由于某种原因无法在数据库上运行,那么这是一个性能密集型解决方案: -
为什么不用“in”代替呢?
要么