Is there a way to perform a FULLTEXT search which returns literals found within words?
I have been using MATCH(col) AGAINST('+literal*' IN BOOLEAN MODE) but it fails if the text is like:
blah,blah,literal,blah
blahliteralblah
blah,blah,literal
Please Note that there is no space after commas.
I want all three cases above to be returned.
I think that should be better fetching the array of entries and then perform a text manipulation over the fetched data (in this case a search)!
Because any text manipulation or complex query take more resources and if your database contains a lot of data, the query become too slow! Moreover, if you are running your
query on a shared server, that increases the performance issues!
You can easily accomplish what you are trying to do with regex, once you have fetched the data from the database!
UPDATE: My suggestion is the same even if you are running your script on a dedicated server! However, if you want to perform a full-text search of the word "literal" in BOOLEAN MODE like you have described, you can remove the + operator (because you are searching only one word) and construct the query as follow:
SELECT listOfColumsNames WHERE
MATCH (colName)
AGAINST ('literal*' IN BOOLEAN MODE);
However, even if you add the AND operator, your query works fine: tested on Apache Server with MySQL 5.1!
I suggest you to read the documentation about the full-text search in boolean mode.
The only one problem of this query is that doesn't matches the word "literal" if it is a sub-string inside an other word, for example: "textliteraltext".
As you noticed, you can't use the * operator at the beginning of the word!
So, to accomplish what you are trying to do, the fastest and easiest way is to follow the suggestion of Paul, using the % placeholder:
SELECT listOfColumsNames
WHERE colName LIKE '%literal%';
Related
I'm trying to create the fastest way to search millions (80+ mio) of records in a PostgreSQL (version 9.4), over multiple columns.
I would like to try and use standard PostgreSQL, and not Solr etc.
I'm currently testing Full Text Search followed https://blog.lateral.io/2015/05/full-text-search-in-milliseconds-with-postgresql/.
It works, but I would like some more flexible way to search.
Currently, if I have a column containing ex. "Volvo" and one containing "Blue" I am able to find the record with the search string "volvo blue", but I would like to also find the record using "volvo blu" as if I used LIKE and "%blu%'.
Is that possible with full text search?
The only option to something like this is by using the pg_trgm contrib module.
This enables you to create a GIN or GiST index that indexes all sequences of three characters, which can be used for a search with the similarity operator %.
Two notes:
Using the % operator may return “false positive” results, so be sure to add a second condition (e.g. with LIKE) that eliminates those.
A trigram search works well with longer search strings, but performs badly with short search strings because of the many false positive results.
If that is not good enough for your purposes, you'll have to resort to an third-party solution.
I have to write a select statement following the following pattern:
[A-Z][0-9][0-9][0-9][0-9][A-Z][0-9][0-9][0-9][0-9][0-9]
The only thing I'm sure of is that the first A-Z WILL be there. All the rest is optional and the optional part is the problem. I don't really know how I could do that.
Some example data:
B/0765/E 3
B/0765/E3
B/0764/A /02
B/0749/K
B/0768/
B/0784//02
B/0807/
My guess is that I best remove al the white spaces and the / in the data and then execute the select statement. But I'm having some problems writing the like pattern actually.. Anyone that could help me out?
The underlying reason for this is that I'm migrating a database. In the old database the values are just in 1 field but in the new one they are splitted into several fields but I first have to write a "control script" to know what records in the old database are not correct.
Even the following isn't working:
where someColumn LIKE '[a-zA-Z]%';
You can use Regular Expression via xQuery to define this pattern. There are many question in StackOverFlow that talk about patterns in DB2, and they have been solved with Regular Expressions.
DB2: find field value where first character is a lower case letter
Emulate REGEXP like behaviour in SQL
I'm using Examine in Umbraco to query Lucene index of content nodes. I have a field "completeNodeText" that is the concatenation of all the node properties (to keep things simple and not search across multiple fields).
I'm accepting user-submitted search terms. When the search term is multiple words (ie, "firstterm secondterm"), I want the resulting query to be an OR query: Bring me back results where fullNodeText is firstterm OR secondterm.
I want:
{+completeNodeText:"firstterm ? secondterm"}
but instead, I'm getting:
{+completeNodeText:"firstterm secondterm"}
If I search for "firstterm OR secondterm" instead of "firstterm secondterm", then the generated query is correctly: {+completeNodeText:"firstterm ? secondterm"}
I'm using the following API calls:
var searcher = ExamineManager.Instance.SearchProviderCollection["ExternalSearcher"];
var searchCriteria = searcher.CreateSearchCriteria();
var query = searchCriteria.Field("completeNodeText", term).Compile();
Is there an easy way to force Examine to generate this "OR" query? Or do I have to manually construct the raw query by calling the StandardAnalyzer to tokenize the user input and concatenating together a query by iterating through the tokens? And bypassing the entire Examine fluent query API?
I don't think that question mark means what you think it means.
It looks like you are generating a PhraseQuery, but you want two disjoint TermQueries. In Lucene query syntax, a phrase query is enclosed in quotes.
"firstterm secondterm"
A phrase query is looking for precisely that phrase, with the two terms appearing consecutively, and in order. Placing an OR within a phrase query does not perform any sort of boolean logic, but rather treats it as the word "OR". The question mark is a placeholder using in PhraseQuery.toString() to represent a removed stop word (See #Lucene-1396). You are still performing a phrasequery, but now it is expecting a three word phrase firstterm, followed by a removed stop word, followed by secondterm
To simply search for two separate terms, get rid of the quotes.
firstterm secondterm
Will search for any document with either of those terms (with higher score given to documents with both).
For some reason I cannot find the answer on Google! But with the SQL contains function how can I tell it to start at the beginning of a string, I.e I am looking for the full-text equivalent to
LIKE 'some_term%'.
I know I can use like, but since I already have the full-text index set up, AND the table is expected to have thousands of rows, I would prefer to use Contains.
Thanks!
You want something like this:
Rather than specify multiple terms, you can use a 'prefix term' if the
terms begin with the same characters. To use a prefix term, specify
the beginning characters, then add an asterisk (*) wildcard to the end
of the term. Enclose the prefix term in double quotes. The following
statement returns the same results as the previous one.
-- Search for all terms that begin with 'storm'
SELECT StormID, StormHead, StormBody FROM StormyWeather
WHERE CONTAINS(StormHead, '"storm*"')
http://www.simple-talk.com/sql/learn-sql-server/full-text-indexing-workbench/
You can use CONTAINS with a LIKE subquery for matching only a start:
SELECT *
FROM (
SELECT *
FROM myTable WHERE CONTAINS('"Alice in wonderland"')
) AS S1
WHERE S1.edition LIKE 'Alice in wonderland%'
This way, the slow LIKE query will be run against a smaller set
The only solution I can think of it to actually prepend a unique word to the beginning of every field in the table.
e.g. Update every row so that 'xfirstword ' appears at the start of the text (e.g. Field1). Then you can search for CONTAINS(Field1, 'NEAR ((xfirstword, "TERM*"),0)')
Pretty crappy solution, especially as we know that the full text index stores the actual position of each word in the text (see this link for details: http://msdn.microsoft.com/en-us/library/ms142551.aspx)
I am facing the similar issue. This is what I have implemented as a work around.
I have made another table and pulled only the rows like 'some_term%'.
Now, on this new table I have implemented the FullText search.
Please do inform me if you tried some other better approach
I would like to run a search with MSSQL Full text engine where given the following user input:
"Hollywood square"
I want the results to have both Hollywood and square[s] in them.
I can create a method on the web server (C#, ASP.NET) to dynamically produce a sql statement like this:
SELECT TITLE
FROM MOVIES
WHERE CONTAINS(TITLE,'"hollywood*"')
AND CONTAINS(TITLE, '"square*"')
Easy enough. HOWEVER, I would like this in a stored procedure for added speed benefit and security for adding parameters.
Can I have my cake and eat it too?
I agreed with above, look into AND clauses
SELECT TITLE
FROM MOVIES
WHERE CONTAINS(TITLE,'"hollywood*" AND "square*"')
However you shouldn't have to split the input sentences, you can use variable
SELECT TITLE
FROM MOVIES
WHERE CONTAINS(TITLE,#parameter)
by the way
search for the exact term (contains)
search for any term in the phrase (freetext)
The last time I had to do this (with MSSQL Server 2005) I ended up moving the whole search functionality over to Lucene (the Java version, though Lucene.Net now exists I believe). I had high hopes of the full text search but this specific problem annoyed me so much I gave up.
Have you tried using the AND logical operator in your string? I pass in a raw string to my sproc and stuff 'AND' between the words.
http://msdn.microsoft.com/en-us/library/ms187787.aspx