CODEWITHSUNDEEP
sqlsql-server
nam vo
nam vo

Reputation: 3437

Sql Select similar text

I have a table Team

Id  Name ...
1    Chelsea
2    Arsenal
3    Liverpool

Now I need to search if my team table has a name like "Chelsea FC". How could I make a select query in this case when search string may have extra words ?

I could try Lucene.net but it's kind of overkill just for a small usage and it would take time to learn it.

Upvotes: 10

Views: 10575

Answers (3)

Phil Walton
Phil Walton

Reputation: 963

You would need to split the string up and search by each word in the string. SQL Server doesn't have a native function to do that, but there are various examples on the web.

This function will take a string and a delimiter, and it will split the string by the delimiter and return a table of the resulting values.

CREATE FUNCTION dbo.SplitVarchar (@stringToSplit varchar(4000), @delimiter CHAR(1))
RETURNS  @Result TABLE(Value VARCHAR(50))AS
BEGIN
    --This CTE will return a table of (INT, INT) that signify the startIndex and stopIndex
    --of each string between delimiters.
    WITH SplitCTE(startIndex, stopIndex) AS
    (
      SELECT 1, CHARINDEX(@delimiter, @stringToSplit)   --The bounds of the first word
      UNION ALL
      SELECT stopIndex + 1, CHARINDEX(@delimiter, @stringToSplit, stopIndex+1)
      FROM SplitCTE             --Recursively call SplitCTE, getting each successive value
      WHERE stopIndex > 0
    )

    INSERT INTO @Result
    SELECT
        SUBSTRING(@stringToSplit,   --String with the delimited data
            startIndex,             --startIndex of a particular word in the string
            CASE WHEN stopIndex > 0 THEN stopIndex-startIndex   --Length of the word
            ELSE 4000 END   --Just in case the delimiter was missing from the string
            ) AS stringValue
    FROM SplitCTE

    RETURN
END;

Once you turn your delimited string into a table, you can JOIN it with the table you wish to search and compare values that way.

DECLARE @TeamName VARCHAR(50)= 'Chelsea FC'

SELECT DISTINCT Name
FROM Team
INNER JOIN (SELECT Value FROM dbo.SplitVarchar(@TeamName, ' ')) t
  ON CHARINDEX(t.Value, Name) > 0

Results:

|    Name |
|---------|
| Chelsea |

SQL Fiddle example

I based my design on Amit Jethva's Convert Comma Separated String to Table : 4 different approaches

Upvotes: 12

Giorgi Nakeuri
Giorgi Nakeuri

Reputation: 35780

You can use like this way:

declare @s varchar(20) = 'Chelsey FC'

select * from Team
where name like '%' + @s + '%' or
        @s like '%' + name + '%'

This will filter rows if @s contains Name or Name contains @s.

Upvotes: 3

ThePravinDeshmukh
ThePravinDeshmukh

Reputation: 1913

Use Full Text Search

To know more about Full Text Search

http://www.developer.com/db/article.php/3446891/Understanding-SQL-Server-Full-Text-Indexing.htm

For implementing it

https://msdn.microsoft.com/en-IN/library/ms142571.aspx

Upvotes: 0

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