我需要一个选择,它将返回如下结果:
SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 word2 word3'
我需要所有的结果,即这包括字符串'word2 word3 word1'或'word1 word3 word2'或任何其他组合的三个。
结果中必须包含所有的单词。
我需要一个选择,它将返回如下结果:
SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 word2 word3'
我需要所有的结果,即这包括字符串'word2 word3 word1'或'word1 word3 word2'或任何其他组合的三个。
结果中必须包含所有的单词。
相当缓慢,但工作方法包括任何单词:
SELECT * FROM mytable
WHERE column1 LIKE '%word1%'
OR column1 LIKE '%word2%'
OR column1 LIKE '%word3%'
如果你需要所有的单词都出现,使用这个:
SELECT * FROM mytable
WHERE column1 LIKE '%word1%'
AND column1 LIKE '%word2%'
AND column1 LIKE '%word3%'
如果您想要更快,您需要研究全文搜索,这对于每种数据库类型都是非常特定的。
SELECT * FROM MyTable WHERE
Column1 LIKE '%word1%'
AND Column1 LIKE '%word2%'
AND Column1 LIKE '%word3%'
根据编辑问题将OR更改为AND。
select * from table where name regexp '^word[1-3]$'
or
select * from table where name in ('word1','word2','word3')
注意,如果使用LIKE来确定一个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匹配字符的模式。
如果你的SQL方言支持CHARINDEX,那么使用它会更容易:
SELECT * FROM MyTable
WHERE CHARINDEX('word1', Column1) > 0
AND CHARINDEX('word2', Column1) > 0
AND CHARINDEX('word3', Column1) > 0
另外,请记住,这和接受的答案中的方法只涵盖子字符串匹配,而不是单词匹配。因此,例如,字符串'word1word2word3'仍然会匹配。
MySQL:
配套功能
-- Split @str by @sep
-- Returns all parts
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
)
查询示例
在MyTable中搜索单词word1, word2, word3。Column1:
-- Create a temporal table (the Data size depends on the length of the word)
DECLARE @FilterTable TABLE (Data VARCHAR(512))
-- Get different and unique words for the search
INSERT INTO @FilterTable (Data)
SELECT DISTINCT S.Data
FROM fnSplit(' ', 'word1 word2 word3') S -- Contains words
-- Search into "MyTable" by "Column1"
SELECT DISTINCT
T.*
FROM
MyTable T
-- Matching records
INNER JOIN @FilterTable F1 ON T.Column1 LIKE '%' + F1.Data + '%'
-- Is some word not present?
LEFT JOIN @FilterTable F2 ON T.Column1 NOT LIKE '%' + F2.Data + '%'
WHERE
-- Is some word not present?
F2.Data IS NULL;
如果你正在使用Oracle数据库,那么你可以使用包含查询来实现这一点。包含查询比同类查询快。
如果你需要所有的单词
SELECT * FROM MyTable WHERE CONTAINS(Column1,'word1 and word2 and word3', 1) > 0
如果你需要什么词的话
SELECT * FROM MyTable WHERE CONTAINS(Column1,'word1 or word2 or word3', 1) > 0
包含列上CONTEXT类型的需要索引。
CREATE INDEX SEARCH_IDX ON MyTable(Column) INDEXTYPE IS CTXSYS.CONTEXT
如果你只是想找到匹配。
SELECT * FROM MyTable WHERE INSTR('word1 word2 word3', Column1)<>0
SQL服务器:
CHARINDEX(Column1, 'word1 word2 word3', 1)<>0
得到精确匹配。例子:(ab;;;交流;,;b)将不会匹配。
SELECT * FROM MyTable WHERE INSTR(';word1;word2;word3;', ';'||Column1||';')<>0
将SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 word2 word3'替换为在这些单词之间添加And:
SELECT * FROM MyTable WHERE Column1 CONTAINS 'word1 And word2 And word3'
详细信息请参见CONTAINS (Transact-SQL)。
在选择短语时,使用双引号:
SELECT * FROM MyTable WHERE Column1 CONTAINS '"Phrase one" And word2 And "Phrase Two"'
附注:在使用contains关键字之前,您必须首先在表上启用全文检索。有关更多详细信息,请参见全文搜索入门。
Use:
SELECT * FROM MyTable WHERE Column1 Like "*word*"
这将显示column1的部分值包含word的所有记录。
尝试在SQL Server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的内存消耗比其他的小。
尝试搜索这个函数:)
最好的方法是在表中的列上创建全文索引 用contains代替LIKE
SELECT * FROM MyTable WHERE
contains(Column1, N'word1')
AND contains(Column1, N'word2')
AND contains(Column1, N'word3')
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
实现问题中提到的最简单的方法之一是使用CONTAINS和NEAR或'~'。例如,下面的查询将为我们提供具体包括word1、word2和word3的所有列。
SELECT * FROM MyTable WHERE CONTAINS(Column1, 'word1 NEAR word2 NEAR word3')
SELECT * FROM MyTable WHERE CONTAINS(Column1, 'word1 ~ word2 ~ word3')
此外,CONTAINSTABLE根据“word1”、“word2”和“word3”的接近度为每个文档返回一个排名。例如,如果一个文档包含这样一句话,“word1是word2和word3”,那么它的排名就会很高,因为这些术语比其他文档中更接近彼此。
我们还可以使用proximity_term来查找单词位于列短语内它们之间的特定距离内的列。
如果使用SQL Server全文搜索,这应该在SQL Server全文搜索的帮助下理想地完成。
然而,如果你因为某些原因不能在你的DB上工作,这里有一个性能密集型的解决方案:
-- 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