Search Database with Keyword:
Is there a way to query the entire table of SQLite database for matching word. I am trying to place a word in keyword JTextField for it search the entire Job table and to return rows which contain that matching words. Each row representing a unique job.
I presume this below snipped structure would not achieve the result
SELECT * FROM Job WHERE Job MATCH 'Microsoft';
Any quick and simple recommendations?
It appears you can use the syntax you're suggesting as long as it's a full text search table:
http://www.phparch.com/2011/11/full-text-search-with-sqlite/
You should probably read the official SQLite documentation on FTS tables. Note that these are "virtual" tables and as such don't use the database file in the same way - this might not be what you want, but it matches the syntax you're looking for. The SQLite page linked has pretty good descriptions. Note that the FTS module is an optional extra which may not be installed.
You shouldn't need to worry about SQL injection attacks as long as you use placeholders. Look at this SO question, specifically the second answer with the code snippet. Essentially you put a ? in the statement, and then supply the string to substitute as a parameter to the query function. That should do SQL escaping for you.
i don't know sqlite but in mysql we have full text search which is used as
select * from table where match(name) against('value')
just see weather full text search is there or not in sqlite, i found this link verify it
http://www.sqlite.org/fts3.html#section_3
Related
I am using SQLite FTS extension in my iOS application.
It performs well but the problem is that it matches only string prefixes (or starts with keyword search).
i.e.
This works:
SELECT FROM tablename WHERE columnname MATCH 'searchterm*'
but following two don't:
SELECT FROM tablename WHERE columnname MATCH '*searchterm'
SELECT FROM tablename WHERE columnname MATCH '\*searchterm\*'
Is there any workaround for this or any way to use FTS to build a query similar to LIKE '%searchterm%' query.
EDIT:
As pointed out by Retterdesdialogs, storing the entire text in reverse order and running a prefix search on a reverse string is a possible solution for ends with/suffix search problem, which was my original question, but it won't work for 'contains' search. I have updated the question accordingly.
In my iOS and Android applications, I have shied away from FTS search for exactly the reason that it doesn't support substring matches due to lack of suffix queries.
The workarounds seem complicated.
I have resorted to using LIKE queries, which while being less performant than MATCH, served my needs.
The workaround is to store the reverse string in an extra column. See this link (its not exactly the same it should give a idea):
Search Suffix using Full Text Search
To get it to work for contains queries, you need to store all suffixes of the terms you want to be able to search. This has the downside of making the database really large, but that can be avoided by compressing the data.
SQLite FTS contains and suffix matches
What are some examples of efficiently searching through a directory as you're typing a person's name?
Say for example, we have a database with 1 million users. We start typing in the search box: "sea", it will display every user's name on a scroll-able window that has "sea" on it (kind of like searching through a Skype directory). After changing a letter, the window should update immediately. All of this is coming from a SQL database. What are few efficient libraries, algorithms that can do this without much delay?
First consider changing the task from "name contains substring" to "name starts with substring". If this is possible, then add index on your name column in database table and use the query:
select name from table where name like :1 || '%'
Limit the number of returned rows using DBMS-specific syntax, for example, for Oracle add
and rownum < 20
This query should return your rows pretty fast.
If you really need "contains substring", then decide whether you want the search to be handled by database or by an external text indexing solution.
For database-contained solution you'll have to use a different approach depending on DBMS. Every one of these solutions requires configuration steps not described here.
For Oracle you can use Oracle Text, see
http://www.oracle.com/technetwork/documentation/index-098492.html
The query will look like
select name from table where contains(name, :1) > 0
For Postgres you can use Full Text Search.
You can also use a solution that is not dependent on the database, for example, see Apache Solr:
http://lucene.apache.org/solr/
for example
SELECT name
FROM Table
WHERE name LIKE '%sea%'
I doing a java project. In this, I have a database table named posts. In this post table there are two fields, they are user and msg.
if msg column contains It is a earthquake data. I need a sql query to extract only the word earthquake from the column. Can I do this ? Help me with Your codes friends......
select * from posts where msg like '%earthquake%'. Note that this query is case sensitive, and hella inefficient. (And also won't play nice with indexes).
Oracle DB has a handy text indexing feature for exactly this kind of problem: http://docs.oracle.com/cd/B28359_01/text.111/b28303/query.htm
It's surprisingly tricky because as soon as you want to look at "words", you're into the realm of language processing rather than simple regexes.
select * from posts where lower(msg) like '%earthquake%'.
This query is not case sensitive. This is more efficient.
Hello World, Here is the situation,
Basically instead of generating values from a table like like so
34.324, 09/13/2011, thankyou,
I would like to generate the type of that specific value
e.g
VarChar2, Date, varchar2(char 30)
Just to add another layer of difficulty a Java application pulls data from the multiple Oracle database tables using HQL. Thus I would need an equivalent HQL statement to the SQL statement (if it exists)..
I understand the DESC keyword lists the column data types for an entire table however as mentioned above I require specificity.
In Summary
I would like to reverse engineer this application to generate a report of the data_types of the data instead of the actual data itself. I could easily just manually walk through the code however they are over 200 entries and this will be a real pain.
Any help is truly appreciated. If this question is unclear please let me know and I will provide more details and examples.
I am working with the Lucene and Derby databases. Lucene contains the text index, and Derby has information regarding additional user data. For example, each document has a tag. For this purpose the Derby database has two tables
TAGS:
ID
Name
LUCENETAGS:
ID
LUCENEID (docID in Lucene, not a field)
TAGID
I want a user to be able to search something like:
very interesting text AND tag:fun
Changing the structure in a way that tag is a Lucene field is not an option.
Thank you!
I believe you'll have to simply perform your text search in Lucene, and then filter your results based on the result of a query into a Derby.
If few documents will match a particular tag, you could also query the database for the IDs to be queried, and rewrite the query like:
(very interesting text) AND id:(1 2 3 etc.)
Probably not feasible, but in the case that tags are pretty sparse, it might be worth considering.
I do wonder, though, why a field can't be added to the index, duplicating the stored value in the Derby Database. In any implementation you choose to get what you want from your stated structure, you will see much poorer performance, and more complexity for you to deal with, than if the data were available in the index as well.