How to make a sql search query more powerful?

Question

I wrote this sql query to search in a table:

SELECT * FROM TableName WHERE Name LIKE '%spa%'

The table contain these row for example:

1. Space Company.
2. Spa resort.
3. Spa hotel.
4. Spare Parts.
5. WithoutTheKeyword.

I want to know how to edit this query so it return the results sorted like this:

2 Spa resort

3 Spa hotel

1 Space Company

4 Spare Parts

Means the items which contain the exact word first then the like ones.

Solution 1

something like

Select * from TableName where Name Like 'Spa%'
ORDER BY case when soundex(name) = soundex('Spa') then '1' else soundex(name) end

should work ok.

actually this will work better

Select * from TableName where Name Like 'Spa%'
ORDER BY DIFFERENCE(name, 'Spa') desc;

FWIW I did some quick tests and if 'Name' is in a NONCLUSTERED INDEX SQL will use the index and doesn't do a table scan. Also, LIKE seems to use less resources than charindex (which returns less desirable results). Tested on sql 2000.

Solution 2

You realize, I presume, that your schema just about eliminates any usefulness of indexes for these kinds of queries?

A big problem is your "LIKE '%spa%'". Any "LIKE" key starting with a wildcard is an automatic table scan.

---

Solution 3

The following should do the necessary, but it's inefficient, doing two full table selects and it also relies on your exact match being delimited by spaces. I think FullText indexing would help, but that has overheads of its own.

select distinct * from
(
Select * from TableName 
   where CHARINDEX('spa ', Name) > 0
   or CHARINDEX(' spa', Name) > 0
Union
Select * from TableName 
  where Name Like '%spa%'
)

Solution 4

You basically need to define (precisely) what your ranking function really is. What if you have a row that is "The Spa." or "spa.com"? Once you have that defined, you need to put that logic into your ORDER BY clause. For example:

SELECT
    name
FROM
    Some_Table
WHERE
    name LIKE '%spa%'
ORDER BY
    CASE
        WHEN name LIKE '% ' + @search_word + ' %' THEN 1   -- Notice the spaces
        ELSE 2
    END,
    name

Alternatively, you could write a ranking function and use that:

SELECT
    name
FROM
    Some_Table
WHERE
    name LIKE '%' + @search_word + '%'
ORDER BY
    dbo.GetNameMatchRank(name, @search_word)

Performance on very large result sets may not be too great, so this approach depends on your expected search result sizes.

Solution 5

Going off the top example, at least in MSSQL2005 changing the CLUSTERED to NONCLUSTERED will make it do a table scan. CLUSTERED gives you an index seek. Looks like it matches the conditions of the question.

CREATE TABLE tblTest(ID INT, colname VARCHAR(20) )
CREATE CLUSTERED INDEX tstidx1_tblTest ON tblTest(colname);
INSERT tblTest SELECT 1,'Space Company'
INSERT tblTest SELECT 2,'Spa Resort'
INSERT tblTest SELECT 3,'Spa Hotel'
INSERT tblTest SELECT 4,'Spare Parts'
INSERT tblTest SELECT 5,'WithoutTheKeyword'

SELECT * FROM tblTest WHERE colname LIKE 'Spa%'
ORDER BY DIFFERENCE(colname,'Spa') DESC;

DROP TABLE tblTest

View more solutions

Comments

[Amr Elgarhy]

you write "soundex(name) = soundex('Spa')", in soundex(name) whats the name equal or should i wrote i like this?

[Amr Elgarhy]

for the first script you wrote, it always give me this error:"Conversion failed when converting the varchar value 'L000' to data type int."

[dkretz]

One field value for "1 Space Company"? Why aren't these two fields - "1" and "Space Company"? It's impossible to create an index on just the name part, and it's apparently really two different data elements, or you wouldn't be asking about sorting on a partial field.

[dkretz]

A big problem is your "LIKE '%spa%'". Any "LIKE" key starting with a wildcard is an automatic table scan.

[Booji Boy]

I'm not sure CHARINDEX('spa ', Name) > 0 would be better. Just because it's a table scan doens't mean it's wrong. I figured this was a search type query anyways and 'Spa' would really be a @FindMe parameter. How about trying to be helpful instead of smarmy?

[Booji Boy]

I disagree. A scan type query is ok sometimes as long it has a narrow focus and isn't the primary means of searching. Oh ya, plus - he's wrong.

[dkretz]

But you fundamentally changed the question by removing the leading wildcard.

[Booji Boy]

Perhaps, I thought is was superfluous. amrelgarhy? I will see if that makes a diff when I get a chance. But still, your answer while perhaps not incorrect could have been phrased in a less condescending tone or even more helpful. I's just trying to defend the new guy.

[dkretz]

You're inferring something I didn't intend to imply. I was trying to give the benefit of the doubt rather than "it's obvious you don't even realize ..." Other responses seem to say that at least a few others read it that way. Although it's always a good reminder to try harder.

[Booji Boy]

ok, my bad then. sorry. I thought the numbers were just a list, not parts of the data to better denote the change in order. All the drama seems a little silly now ;D. It is an interesting problem.

[RichieHH]

Bit late but this is nonsense. If the need is to find something inside a field it's unavoidable