Sql server function for displaying word frequency in a column

Question

I have a table that lists a freet text input from a survey where enterents were allowed to enter their responses (regarding colours they would like to have in their wedding)

Answer 1

Okay this works a treat. Firstly a function to separate the values...

Alter Function dbo.SeparateValues    

(    
 @data VARCHAR(MAX),    
 @delimiter VARCHAR(10)     
)     
RETURNS     
@tbldata TABLE(col VARCHAR(MAX))    
As    
--Declare @data VARCHAR(MAX) ,@delimiter VARCHAR(10)     
--Declare @tbldata TABLE(col VARCHAR(10))    
--Set @data = 'hello,how,are,you?,234234'    
--Set @delimiter = ','    
--DECLARE @tbl TABLE(col VARCHAR(10))    
Begin    
DECLARE @pos INT    
DECLARE @prevpos INT    
SET @pos = 1     
SET @prevpos = 0    

WHILE @pos > 0     
BEGIN    
SET @pos = CHARINDEX(@delimiter, @data, @prevpos+1)    
if @pos > 0     
INSERT INTO @tbldata(col) VALUES(LTRIM(RTRIM(SUBSTRING(@data, @prevpos+1, @pos-@prevpos-1))))    
else    
INSERT INTO @tbldata(col) VALUES(LTRIM(RTRIM(SUBSTRING(@data, @prevpos+1, len(@data)-@prevpos))))    
SET @prevpos = @pos     
End    

RETURN       
END    

then I just apply it to my table...

Select Count(*), sep.Col FROM (
        Select * FROM (
            Select value = Upper(RTrim(LTrim(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(Replace(response, ',', ' '), '.', ' '), '!', ' '), '+', ' '), ':', ' '), '-', ' '), ';', ' '), '(', ' '), ')', ' '), '/', ' '), '&', ''), '?', ' '), '  ', ' '), '  ', ' ')))) FROM Responses
        ) easyValues
        Where value <> '' 
    ) actualValues 
    Cross Apply dbo.SeparateValues(value, ' ') sep
    Group By sep.Col
    Order By Count(*) Desc

Okay, so I went OTT with my nested tables, but I've stripped out all the crap characters, separated the values and kept a running total of the most frequently used words.

Answer 2

DECLARE @phrases TABLE (id int, phrase varchar(max))
INSERT @phrases values
(1,'Red and White'  ),
(2,'green'          ),
(3,'White and blue' ),
(4,'Blue'           ),
(5,'Dark blue'      );

SELECT word, COUNT(*) c
FROM @phrases
CROSS APPLY (SELECT CAST('<a>'+REPLACE(phrase,' ','</a><a>')+'</a>' AS xml) xml1 ) t1
CROSS APPLY (SELECT n.value('.','varchar(max)') AS word FROM xml1.nodes('a') x(n) ) t2
GROUP BY word

word         freq
----------- -----------
and         2
blue        3
Dark        1
green       1
Red         1
White       2

Answer 3

You're main problem is that you're missing a split function in SQL Server.

Theres a sample one here that looks pretty good..

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=50648

Using that, you write a stored proc along the lines of...

CREATE TABLE #Temp (Response nvarchar(50), Frequency int) 

DECLARE @response nvarchar(100)
DECLARE db_cursor CURSOR FOR 
SELECT response FROM YourTable

OPEN db_cursor  
FETCH NEXT FROM db_cursor INTO @response 

WHILE @@FETCH_STATUS = 0  
BEGIN  
       /* Pseudo Code */ 
       --Split @Response 
       --Iterate through each word in returned list
       --IF(EXISTS in #TEMP)
       --    UPDATE THAT ROW & INCREMENT THE FREQUENCY
       --ELSE
       --    NEW WORD, INSERT TO #Temp WITH A FREQUENCY OF 1

       FETCH NEXT FROM db_cursor INTO @response 
END   

SELECT * FROM #Temp

Theres probably a less fugly way to do this without cursors, but if it's just something you need to run once, and you're table or Responses isn't phenomenally large, then this should work