if you want to query the productname, you should add a new property inside the tbl_order named productname and since this property is just used for this model, you could add the Notmapped attribute for it to tel
Combine multiple tables with JOINs in T-SQL Documentation Use LINQ to construct a query (Microsoft Dataverse) - Power Apps Describes how to use the .NET Language-Integrated Query (LINQ) query provider to construct a Microsoft Dataverse query. Cross-Table Queries (LINQ to DataSet) - ADO....
Filter multiple tables You can create complex .NET Language Integrated Query(LINQ) queries in Dataverse. You use multiple Join clauses with filter clauses to create a result that is filtered on columns from several tables. The following sample shows how to create a LINQ query that w...
To see another approach to querying data stored in Excel tables, check out Eric White'sUsing LINQ to Query Excel Tablesblog post. It provides sample code that includes a set of extension methods and classes that allow queries to be performed against Excel tables using LINQ in a manner that ...
DataSet ds = new DataSet(); ds.Locale = CultureInfo.InvariantCulture; FillDataSet(ds); DataTable products = ds.Tables["Product"]; IEnumerable<DataRow> productList = products.AsEnumerable().ToList(); IEnumerable<DataRow> query = from product in productList orderby product.Fiel...
This deferred evaluation allows queries to be kept as IEnumerable<T>-based values that can be evaluated multiple times, each time yielding potentially different results. For many applications, this is exactly the behavior that is desired. For applications that want to cache the results of query ...
You need to execute the same parameterized query multiple times with different parameter values, but you want to avoid the overhead of parsing the query expression tree to build the parameterized SQL each time the query executes. Solution Use the CompiledQuery.Compile method to build an expression...
Similarly, we can break an update query into multiple pieces if needed:using LinqToDB; using var db = new DbNorthwind(); var statement = db.Product .Where(p => p.ProductID == product.ProductID) .Set(p => p.Name, product.Name); if (updatePrice) statement = statement.Set(p => p...
To avoid executing multiple times convert the results into any number of standard collection classes. It is easy to convert the results into a list or array using the standard query operatorsToList() orToArray().C# var q = from c in db.Customers where c.City == "London" select c;//...
Of course, application writers often need to be very explicit about where and when a query is executed. It would be unexpected if an application were to execute a query multiple times simply because it needed to examine the results more than once. For example, you may want to bind the res...