I am building a Search function for a shopping cart site, which queries a SQL Server database. When the user enters "Hula Hoops" in the search box, I want results for all records containing both "Hula" and "Hoop", in any order. Furthermore, I need to search multiple columns (i.e. ProductName, Description, ShortName, MaufacturerName, etc.)
All of these product names should be returned, when searching for "Hula hoop":
Hula hoop
Hoop Hula
The Hoopity of xxhula sticks
(Bonus points if these can be ordered by relevance!)
It sounds like you're really looking for full-text search, especially since you want to weight the words.
In order to use LIKE, you'll have to use multiple expressions (one per word, per column), which means dynamic SQL. I don't know which language you're using, so I can't provide an example, but you'll have to produce a statement that's like this:
For "Hula Hoops":
where (ProductName like '%hula%' or ProductName like '%hoops%')
and (Description like '%hula%' or Description like '%hoops%')
and (ShortName like '%hula%' or ShortName like '%hoops%')
etc.
Unfortunately, that's really the only way to do it. Using Full Text Search would allow you to reduce your criteria to one per column, but you'll still have to specify the columns explicitly.
Since you're using SQL Server, I'm going to hazard a guess that this is a C# question. You'd have to do something like this (assuming you're constructing the SqlCommand or DbCommand object yourself; if you're using an ORM, all bets are off and you probably wouldn't be asking this anyway):
SqlCommand command = new SqlCommand();
int paramCount = 0;
string searchTerms = "Hula Hoops";
string commandPrefix = #"select *
from Products";
StringBuilder whereBuilder = new StringBuilder();
foreach(string term in searchTerms.Split(' '))
{
if(whereBuilder.Length == 0)
{
whereBuilder.Append(" where ");
}
else
{
whereBuilder.Append(" and ");
}
paramCount++;
SqlParameter param = new SqlParameter(string.Format("param{0}",paramCount), "%" + term + "%");
command.Parameters.Add(param);
whereBuilder.AppendFormat("(ProductName like #param{0} or Description like #param{0} or ShortName like #param{0})",paramCount);
}
command.CommandText = commandPrefix + whereBuilder.ToString();
SQL Server Full Text Search should help you out. You will basically create indexes on the columns you want to search. in the where clause of your query you will use the CONTAINS operator and pass it your search input.
you can start HERE or HERE to learn more
You might want to check out SOLR too - if you're going to be doing this type of searching. Super cool.
http://lucene.apache.org/solr/
Related
I have two columns in a table first_name and last_name(PostgreSQL).
In front end, I have an input to allow users to search for people. It is an auto-complete field that calls a web service for searching people by first and/or last names.
Currently, I have made a query (using my query builder):
$searches = preg_split('/\s+/', $search);
if (!empty($search)) {
$orX = $query->expr()->orX();
$i = 0;
foreach ($searches as $value) {
$orX->add($query->expr()->eq('c.firstName', ':name'.$i));
$orX->add($query->expr()->eq('c.lastName', ':name'.$i));
$query->setParameter('name'.$i, $value);
$i++;
}
$query->andWhere($orX);
}
But this query is not as precise as it is required, it uses OR for every word so if I am looking for "Rasmus Lerdorf" it also gives me "Rasmus Adams" and "Adel Lerdorf". It works only if I enter a single word ("Rasmus" for example), in this case it gives me all people with "Rasmus" as first_name or last_name.
I read about MATCH AGAINST but I am using PostgreSQL. I also heard about Full text search feature in PostgreSQL as the equivalent of MATCH AGAINST, but I am wondering if implementing a full text search would be an overkill for such an objective (especially that the maximum number of words in both columns wouldn't exceed 4).
I ask you please your advices, your usual help is always appreciated. Thanks
You don't need fulltext search.
Just add the different search terms with AND instead of OR:
$i = 0;
foreach ($searches as $value) {
$orX = $query->expr()->orX();
$orX->add($query->expr()->eq('c.firstName', ':name'.$i));
$orX->add($query->expr()->eq('c.lastName', ':name'.$i));
$query->setParameter('name'.$i, $value);
$i++;
$query->andWhere($orX);
}
I would also suggest using LIKE instead of an equality comparison (add '%' to the start and end of the users search term), and probably also make everything case insensitive by adding $query->expr()->lower() appropriately.
I have Lucene index which has city names.
Consider I want to search for 'New Delhi'. I have string 'New Del' which I want to pass to Lucene searcher and I am expecting output as 'New Delhi'.
If I generate query like Name:New Del* It will give me all cities with 'New and Del'in it.
Is there any way by which I can create Lucene query wildcard query with spaces in it?
I referred and tried few solutions given # http://www.gossamer-threads.com/lists/lucene/java-user/5487
It sounds like you have indexed your city names with analysis. That will tend to make this more difficult. With analysis, "new" and "delhi" are separate terms, and must be treated as such. Searching over multiple terms with wildcards like this tends to be a bit more difficult.
The easiest solution would be to index your city names without tokenization (lowercasing might not be a bad idea though). Then you would be able to search with the query parser simply by escaping the space:
QueryParser parser = new QueryParser("defaultField", analyzer);
Query query = parser.parse("cityname:new\\ del*");
Or you could use a simple WildcardQuery:
Query query = new WildcardQuery(new Term("cityname", "new del*"));
With the field analyzed by standard analyzer:
You will need to rely on SpanQueries, something like this:
SpanQuery queryPart1 = new SpanTermQuery(new Term("cityname", "new"));
SpanQuery queryPart2 = new SpanMultiTermQueryWrapper(new WildcardQuery(new Term("cityname", "del*")));
Query query = new SpanNearQuery(new SpanQuery[] {query1, query2}, 0, true);
Or, you can use the surround query parser (which provides query syntax intended to provide more robust support of span queries), using a query like W(new, del*):
org.apache.lucene.queryparser.surround.parser.QueryParser surroundparser = new org.apache.lucene.queryparser.surround.parser.QueryParser();
SrndQuery srndquery = surroundparser.parse("W(new, del*)");
query = srndquery.makeLuceneQueryField("cityname", new BasicQueryFactory());
As I learnt from the thread mentioned by you (http://www.gossamer-threads.com/lists/lucene/java-user/5487), you can either do an exact match with space or treat either parts w/ wild card.
So something like this should work - [New* Del*]
So I have a database with articles in them and the user should be able to search for a keyword they input and the search should find any articles with that word in it.
So for example if someone were to search for the word Alzheimer's I would want it to return articles with the word spell in any way regardless of the apostrophe so;
Alzheimer's
Alzheimers
results should all be returned. At the minute it is search for the exact way the word is spell and wont bring results back if it has punctuation.
So what I have at the minute for the query is:
private static final String QUERY_FIND_BY_SEARCH_TEXT = "SELECT o FROM EmailArticle o where UPPER(o.headline) LIKE :headline OR UPPER(o.implication) LIKE :implication OR UPPER(o.summary) LIKE :summary";
And the user's input is called 'searchText' which comes from the input box.
public static List<EmailArticle> findAllEmailArticlesByHeadlineOrSummaryOrImplication(String searchText) {
Query query = entityManager().createQuery(QUERY_FIND_BY_SEARCH_TEXT, EmailArticle.class);
String searchTextUpperCase = "%" + searchText.toUpperCase() + "%";
query.setParameter("headline", searchTextUpperCase);
query.setParameter("implication", searchTextUpperCase);
query.setParameter("summary", searchTextUpperCase);
List<EmailArticle> emailArticles = query.getResultList();
return emailArticles;
}
So I would like to bring back all results for alzheimer's regardless of weather their is an apostrophe or not. I think I have given enough information but if you need more just say. Not really sure where to go with it or how to do it, is it possible to just replace/remove all punctuation or just apostrophes from a user search?
In my point of view, you should change your query,
you should add alter your table and add a FULLTEXT index to your columns (headline, implication, summary).
You should also use MATCH-AGAINST rather than using LIKE query and most important, read about SOUNDEX() syntax, very beautiful syntax.
All I can give you is a native query example:
SELECT o.* FROM email_article o WHERE MATCH(o.headline, o.implication, o.summary) AGAINST('your-text') OR SOUNDEX(o.headline) LIKE SOUNDEX('your-text') OR SOUNDEX(o.implication) LIKE SOUNDEX('your-text') OR SOUNDEX(o.summary) LIKE SOUNDEX('your-text') ;
Though it won't give you results like Google search but it works to some extent. Let me know what you think.
I am querying a MS SQL database using Linq and Entity Framework Code First. The requirement is to be able to run a WHERE SomeColumn LIKE '%sometext'clause against the table.
This, on the surface, is a simple requirement that could be accomplished using a simple Linq query like this:
var results = new List<MyTable>();
using(var context = new MyContext())
{
results = context.MyTableQueryable
.Where(x => x.SomeColumn.EndsWith("sometext"))
.ToList();
}
// use results
However, this was not effective in practice. The problem seems to be that the column SomeColumn is not varchar, rather it's a char(31). This means that if a string is saved in the column that is less than 31 characters then there will be spaces added on the end of the string to ensure a length of 31 characters, and that fouls up the .EndsWith() query.
I used SQL Profiler to lookup the exact sql that was generated from the .EndsWith() method. Here is what I found:
--previous query code removed for brevity
WHERE [Extent1].[SomeColumn] LIKE N'%sometext'
So that is interesting. I'm not sure what the N means before '%sometext'. (I'll Google it later.) But I do know that if I take the same query and run it in SSMS without the N like this:
--previous query code removed for brevity
WHERE [Extent1].[SomeColumn] LIKE '%sometext'
Then the query works fine. Is there a way to get Linq and Entity Framework to drop that N from the query?
Please try this...
.Where(x => x.SomeColumn.Trim().EndsWith("sometext"))
Just spoke to my colleague who had a similar issue, see if the following works for you:
[Column(TypeName = "varchar")]
public string SomeColumn
{
get;
set;
}
Apparently setting the type on the column mapping will force the query to recognise it as a VARCHAR, where a string is normally interpreted as an NVARCHAR.
I want to query a table and only need one cell returned. Right now the only way I can think to do it is:
$query = $this->db->query('SELECT id FROM crops WHERE name = "wheat"');
if ($query->num_rows() > 0) {
$row = $query->row();
$crop_id = $row->id;
}
What I want is, since I'm select 'id' anyway, for that to be the result. IE: $query = 'cropId'.
Any ideas? Is this even possible?
Of course it's possible. Just use AND in your query:
$query = $this->db->query('SELECT id FROM crops WHERE name = "wheat" AND id = {$cropId}');
Or you could use the raw power of the provided Active Record class:
$this->db->select('id');
$this->db->from('crops');
$this->db->where('name','wheat');
$this->db->where('id',$cropId);
$query = $this->db->get();
If you just want the cropId from the whole column:
foreach ($query->result()->id as $cropId)
{
echo $cropId;
}
Try this out, I'm not sure if it will work:
$cropId = $query->first_row()->id;
Note that you want to swap your quotes around: use " for your PHP strings, and ' for your SQL strings. First of all, it would not be compatible with PostgreSQL and other database systems that check such things.
Otherwise, as Christopher told you, you can test the crop identifier in your query. Only if you define a string between '...' in PHP, the variables are not going to be replaced in the strings. So he showed the wrong PHP code.
"SELECT ... $somevar ..."
will work better.
Yet, there is a security issue in writing such strings: it is very dangerous because $somevar could represent some additional SQL and completely transform your SELECT in something that you do not even want to think about. Therefore, the Active Record as mentioned by Christopher is a lot safer.