It uses the same standard
query operators and query patterns because of its tight integration with LINQ. There are subtle
differences between some of the query items. For example, items such as filtering and grouping are
the same, but the variable of the return type for LINQ to SQL must be of IQueryable(of T) instead
of the IEnumerable that a standard LINQ query uses.
Part III: LINQ to SQL
The following table lists the similarities and differences between a standard LINQ query and a LINQ to
SQL query. Notice that most of the query items are identical, meaning that they follow the same syntax.
The only differences are the way joins are handled and the query variable return type.
Query Item LINQ LINQ to SQL
Query variable return type IEnumerable IQueryable
Data source specification From/from equivalent
Filtering Where/where equivalent
Grouping Goupby equivalent
Selecting Select/select equivalent
Joins join Association attribute
In LINQ to SQL joins, the recommended technique is to use the Association attribute, but as you saw in
Chapter 3, it is possible to use the join clause.
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