Best way of constructing dynamic sql queries in C#/.NET3.5? -

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a project i'm working on @ moment involves refactoring c# com object serves database access layer sql 2005 databases.

the author of existent code has built sql queries manually using string , many if-statements construct complex sql statement (~10 joins, >10 sub selects, ~15-25 conditions , groupby's). base table same one, structure of joins, conditions , groupings depend on set of parameters passed class/method.

constructing sql query work isn't elegant solution (and rather hard read/understand , maintain well)... write simple "querybuilder" myself pretty sure not first 1 kind of problem, hence questions:

  • how you construct database queries?
  • does c# offer easy way dynamically build queries?

i used c# , linq similar log entries filtered on user input (see conditional linq queries):

iqueryable<log> matches = m_locator.logs;  // users filter if (usersfilter)     matches = matches.where(l => l.username == comboboxusers.text);   // severity filter  if (severityfilter)      matches = matches.where(l => l.severity == comboboxseverity.text);   logs = (from log in matches          orderby log.eventtime descending          select log).tolist();

edit: query isn't performed until .tolist() in last statement.


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