SQL WHILE loop inside WHERE clause - sql-server

Question

Can I put a WHILE loop inside WHERE clause? I have a stored procedure where I'm trying to put in text searching capability. I have it working for an exact match like this:
AND (#exactString = ''
OR (CHARINDEX(#exactString, [Short Description]) > 0
OR CHARINDEX(#exactString, [Description]) > 0
OR CHARINDEX(#exactString, [Manufacturer]) > 0))
Next I'm trying to do a "any word" match and an "all words" match. I can get the search string I want to search for with the following WHILE loop:
DECLARE #searchString varchar(max)
DECLARE #endIndex int
SET #allString = LTRIM(RTRIM(#allString))
WHILE LEN(#allString) > 0
BEGIN
SET #endIndex = CHARINDEX(' ', #allString) > 0
IF #endIndex > 0
BEGIN
SET #searchString = LEFT(#allString, #endIndex)
SET #allString = LTRIM(RTRIM(RIGHT(#allString, #endIndex)))
END
ELSE
BEGIN
SET #searchString = #allString
SET #allString = ''
END
END
Now I want to use the #searchString variable like I used #exactString above. Is there a way to do this inside my loop or is there some other technique I'm missing that would work here?
Thanks for your help,
Dan

Answer 1

I have used a table value function to perform this task using a query such as the following:
SELECT I.*
FROM #info AS I
INNER JOIN dbo.funcSplitToTable( ' ', #allString ) AS S
ON I.[Manufacturer] LIKE '%' + S.result + '%'
OR I.[Description] LIKE '%' + S.result + '%'
OR I.[Short Description] LIKE '%' + S.result + '%'
This table value function is defined as follows:
CREATE FUNCTION dbo.funcSplitToTable
/*
Split a string into parts base on a separation character to produce
a table that has one column containing the results of the split.
EXAMPLE:
SELECT * FROM dbo.funcSplitToTable( '~', 'MAINT~12221~10001~10/25/2004~CANCELLED~1' )
SELECT * FROM dbo.funcSplitToTable( '~', '' )
SELECT * FROM dbo.funcSplitToTable( '~', NULL )
SELECT * FROM dbo.funcSplitToTable( NULL, 'MAINT~12221~10001~10/25/2004~CANCELLED~1' )
SELECT * FROM dbo.funcSplitToTable( '', 'MAINT~12221~10001~10/25/2004~CANCELLED~1' )
RETURN:
Table with one column containing resulting strings.
*/
(
#strSearch AS varchar(255) -- String to search for.
,#strText AS varchar(MAX ) -- Text to search for string.
)
RETURNS #tblResult TABLE (
result varchar(MAX) NOT NULL
)
WITH SCHEMABINDING
AS
BEGIN
DECLARE #iLastPos int
DECLARE #iPos int
DECLARE #strResult varchar(MAX)
IF #strText IS NULL RETURN ;
IF #strSearch IS NULL SET #strSearch = '' ;
SET #strResult = NULL ;
SET #iLastPos = 1 ;
SET #iPos = CHARINDEX( #strSearch, #strText ) ;
WHILE #iPos > 0
BEGIN
IF (#iPos - #iLastPos) > 0
INSERT INTO #tblResult
SELECT SUBSTRING( #strText, #iLastPos, (#iPos - #iLastPos) ) AS result
;
SET #iLastPos = #iPos + 1 ;
SET #iPos = CHARINDEX( #strSearch, #strText, #iLastPos ) ;
END
IF (1 + LEN(#strText) - #iLastPos) > 0
INSERT INTO #tblResult
SELECT SUBSTRING( #strText, #iLastPos, (1 + LEN(#strText) - #iLastPos) ) AS result
;
RETURN ;
END

Answer 2

I got a great answer from Michael Erickson that totally works for the "any" search. For the "all" search. I built up an sql string with the entire query. The "all" search section is here:
IF LEN(#allString) > 0
BEGIN
DECLARE #searchString varchar(max)
DECLARE #endIndex int
DECLARE #isFirstString bit
SET #isFirstString = 0
SET #allString = LTRIM(RTRIM(#allString))
WHILE LEN(#allString) > 0
BEGIN
SET #endIndex = CHARINDEX(' ', #allString)
IF #endIndex > 0
BEGIN
SET #searchString = LTRIM(RTRIM(LEFT(#allString, #endIndex)))
SET #allString = LTRIM(RTRIM(RIGHT(#allString, LEN(#allString) - #endIndex)))
END
ELSE
BEGIN
SET #searchString = #allString
SET #allString = ''
END
SET #sql = #sql + ' AND ((CHARINDEX(''' + cast(#searchString as varchar(max)) + ''', [Short Description]) > 0
OR CHARINDEX(''' + cast(#searchString as varchar(max)) + ''', [Description]) > 0
OR CHARINDEX(''' + cast(#searchString as varchar(max)) + ''', [Manufacturer]) > 0))'
END
END
EXEC (#sql)
Thanks again,
Dan