Which is the first option in creating subqueries in LINQ?
Which leads to your first option in creating subqueries in LINQ. LINQ doesn’t execute your query until you “realize” it. You can realize a query by calling some method on it (ToList is a good example) or by working with individual objects in the result (by using a foreach loop to process each object in the query’s result).
Can a join be used in a delete query in slick?
A query for deleting must only use a single table – no joins are allowed (Slick does not yet support the USING keyword for deletes). Any projection is ignored (it always deletes full rows). If you need to perform a join, you can filter based on another Query:
Where can I find the methods in slick?
The actual methods can be found in the classes AnyExtensionMethods, ColumnExtensionMethods , NumericColumnExtensionMethods, BooleanColumnExtensionMethods and StringColumnExtensionMethods (cf. ExtensionMethods ).
How to do a subquery in Stack Overflow?
There is a FK relationship between CompanyRolesToUsers and Users, but it’s a many to many relationship and CompanyRolesToUsers is the junction table. We already have most of our site built, and we already have most of the filtering working by building Expressions using a PredicateExtensions class.
A query for deleting must only use a single table – no joins are allowed (Slick does not yet support the USING keyword for deletes). Any projection is ignored (it always deletes full rows). If you need to perform a join, you can filter based on another Query:
When does the subquery execute before the main query?
The subquery (inner query) executes once before the main query (outer query) executes. The main query (outer query) use the subquery result. In this section, you will learn the requirements of using subqueries. We have the following two tables ‘student’ and ‘marks’ with common field ‘StudentID’.
The actual methods can be found in the classes AnyExtensionMethods, ColumnExtensionMethods , NumericColumnExtensionMethods, BooleanColumnExtensionMethods and StringColumnExtensionMethods (cf. ExtensionMethods ).
How to check if an expression is included in a subquery?
Compare an expression to the result of the query. Determine if an expression is included in the results of the query. Check whether the query selects any rows. The subquery (inner query) executes once before the main query (outer query) executes. The main query (outer query) use the subquery result.