I'm doing some basic statistical calculations on the results of a survey. A survey consists of several sections and each section has some questions in it. The answers to each question in each section are stored.
ResultsTable table has
Result column which contains computed result for the entire survey as well as overall results for each section, separated by double pipe. For example,
Above, Moderate is overall survey result, Low is result for section 1, High is for section 2 and so on.
(Then I would be computing some statistics, such as % of people who have High as their result for a specific section. Or, of those who have High for a specific section the % who answered Yes or No to a specific question in that section, etc.)
The problem I'm facing is that I need to split string, which I think could cause performance problems. What I have right now is as follows.
SELECT COUNT(*) [Personal_Health_High_Risk] FROM ( SELECT rt.* FROM ResultsTable rt WHERE rt.CampaignID IN (SELECT Value FROM ufn_ParseDelimitedString(@campaignIDs, ',')) AND rt.SectionID = @sectionID ) sq WHERE -- where 3rd section result is High (SELECT Value FROM ufn_ParseDelimitedString(sq.Result, '||') WHERE RowNumber = 4 ) LIKE '%High%'
ufn_ParseDelimitedString function splits a string using given delimiter and returns resulting tokens in a table. For example,
-- ufn_ParseDelimitedString output: -- [RowNumber] [Value] -- 1 Moderate -- 2 Low -- 3 High -- ...
So, is it better to continue with what I'm doing - basically split the string on each select? OR I was thinking taking that inner
SELECT in code above and saving output into temporary table and actually expanding the concatenated result string into separate columns. This way I could reuse temporary table for various other calculations. What are your thoughts on this?