This document discusses querying data sources using IQueryProvider. It shows code for executing a query generically on a source and for creating a query by calling a generic method and passing the source expression and a predicate expression. It also compares different ways to check for string equality in C#, showing that s1 == s2, s1.Equals(s2), String.Equals(s1, s2), and String.Compare(s1, s2) == 0 all perform the same check.

6. IQUERY
PROVIDER

7. source
.Provider
.Execute<int>(
Expression.Call(null,
((MethodInfo) MethodBase
.GetCurrentMethod())
.MakeGenericMethod(
new Type[] {
typeof(TSource) }),
new Expression[] {source.Expression }));

8. Source
.Provider
.CreateQuery<TSource>(
Expression.Call(
null,
((MethodInfo)
MethodBase
.GetCurrentMethod())
.MakeGenericMethod(
new Type[] { typeof(TSource) }),
new Expression[] {
source.Expression,
Expression.Quote(predicate) }));

9. IQUERY
PROVIDER

10. IQUERY
PROVIDER

11. IQUERY
PROVIDER

14. //is it the same thing?
s1 == s2
s1.Equals(s2)
String.Equals(s1, s2)
String.Compare(s1, s2) == 0

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