First, I have a variable like below:
List<string> values;
Now I need build query condition like below:
Expression<Func<docinstance, bool>> filter = d=>d.values.any(o=>o.value==values[0]||o.value==value[1]||.....)
Because I don't know how many items in variable values, so how can I build the query condition
You can use Any again inside
d => d.values.Any(o => values.Any(x => x == o.value))
2(n-1) UNIONs of single row tables. Contains is much better (1 IN clause).
Contains has scalability problems, but Any is not scalable at all. When values has relatively many elements (~50) the query will throw an exception "nested too deeply".The DbContext class of EF has a method Set<TEntity>() which return type is DbSet<TEntity> which implements Queryable interface which has all the query methods as extension methods.
At the end your query expression in translated into SQL and then executed. Which gives you the desired capability so that you can combine query methods and construct dynamic expressions.
