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    <p>To avoid making N queries to the database, something that could be very expensive in terms of processing, network and so worth, I suggest you to Join only once using a trick I learned. First you need a function in your database that splits a string into a table.</p> <pre><code>CREATE FUNCTION [DelimitedSplit8K] --===== Define I/O parameters (@pString VARCHAR(8000), @pDelimiter CHAR(1)) RETURNS TABLE WITH SCHEMABINDING AS RETURN --===== "Inline" CTE Driven "Tally Table" produces values from 0 up to 10,000... -- enough to cover VARCHAR(8000) WITH E1(N) AS ( SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 ), --10E+1 or 10 rows E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max cteTally(N) AS (--==== This provides the "zero base" and limits the number of rows right up front -- for both a performance gain and prevention of accidental "overruns" SELECT 0 UNION ALL SELECT TOP (DATALENGTH(ISNULL(@pString,1))) ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4 ), cteStart(N1) AS (--==== This returns N+1 (starting position of each "element" just once for each delimiter) SELECT t.N+1 FROM cteTally t WHERE (SUBSTRING(@pString,t.N,1) = @pDelimiter OR t.N = 0) ) --===== Do the actual split. The ISNULL/NULLIF combo handles the length for the final element when no delimiter is found. SELECT ItemNumber = ROW_NUMBER() OVER(ORDER BY s.N1), Item = SUBSTRING(@pString,s.N1,ISNULL(NULLIF(CHARINDEX(@pDelimiter,@pString,s.N1),0)-s.N1,8000)) FROM cteStart s GO </code></pre> <p>Second, concatenate your 100 variables into 1 string:</p> <p>"Value1", "Value 2", "Value 3"....</p> <p>In Sql Server you can just join the values with your table</p> <pre><code>SELECT somecolumn FROM sometable t INNER JOIN [DelimitedSplit8K](@DelimitedString, ',') v ON v.Item = t.somecolumn </code></pre> <p>So you find 100 strings at a time with only 1 query. </p>
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