LINQ: Split Where OR conditions
.net, linq, multiple-conditions, sql, where-clause
Solution
There are a few ways to go about this:
Apply the "where" to the original query each time, and then `Union()` the resulting queries.
var queries = new List<IQueryable<Session>>();
if (!String.IsNullOrEmpty(Division)) {
queries.Add(sessions.Where(y => y.session.SESSION_DIVISION.Any(x => x.DIVISION.ToUpper().Contains(SearchContent))));
}
if (!String.IsNullOrEmpty(Room)) {
// this shoudl be OR
queries.Add(sessions.Where(y => y.session.ROOM.ToUpper().Contains(SearchContent)));
}
if (!String.IsNullOrEmpty(course)) {
// this shoudl be OR
queries.Add(sessions.Where(y => y.session.COURSE.ToUpper().Contains(SearchContent)));
}
sessions = queries.Aggregate(sessions.Where(y => false), (q1, q2) => q1.Union(q2));
Do Expression manipulation to merge the bodies of your lambda expressions together, joined by `OrElse` expressions. (Complicated unless you've already got libraries to help you: after joining the bodies, you also have to traverse the expression tree to replace the parameter expressions. It can get sticky. See this post for details.
- Use a tool like PredicateBuilder to do #2 for you.
Problem
So I have the following where conditions ``` sessions = sessions.Where(y => y.session.SESSION_DIVISION.Any(x => x.DIVISION.ToUpper().Contains(SearchContent)) || y.session.ROOM.ToUpper().Contains(SearchContent) || y.session.COURSE.ToUpper().Contains(SearchContent)); ``` I want to split this into multiple lines based on whether a string is empty for example: ``` if (!String.IsNullOrEmpty(Division)) { sessions = sessions.Where(y => y.session.SESSION_DIVISION.Any(x => x.DIVISION.ToUpper().Contains(SearchContent))); } if (!String.IsNullOrEmpty(Room)) { // this shoudl be OR sessions = sessions.Where(y => y.session.ROOM.ToUpper().Contains(SearchContent)); } if (!String.IsNullOrEmpty(course)) { // this shoudl be OR sessions = sessions.Where(y => y.session.COURSE.ToUpper().Contains(SearchContent)); } ``` If you notice I want to add multiple OR conditions split based on whether the Room, course, and Division strings are empty or not.