Cláusula Let (Visual Basic)
Computes a value and assigns it to a new variable within the query.
Let variable = expression [, ...]
Parts
Term |
Definition |
variable |
Required. An alias that can be used to reference the results of the supplied expression. |
expression |
Required. An expression that will be evaluated and assigned to the specified variable. |
Comentários
The Let clause enables you to compute values for each query result and reference them by using an alias. The alias can be used in other clauses, such as the Where clause. The Let clause enables you to create a query statement that is easier to read because you can specify an alias for an expression clause included in the query and substitute the alias each time the expression clause is used.
You can include any number of variable and expression assignments in the Let clause. Separate each assignment with a comma (,).
Exemplo
The following code example uses the Let clause to compute a 10 percent discount on products.
Dim discountedProducts = From prod In products
Let Discount = prod.UnitPrice * 0.1
Where Discount >= 50
Select prod.ProductName, prod.UnitPrice, Discount
For Each prod In discountedProducts
Console.WriteLine("Product: {0}, Price: {1}, Discounted Price: {2}",
prod.ProductName, prod.UnitPrice.ToString("$#.00"),
(prod.UnitPrice - prod.Discount).ToString("$#.00"))
Next
Consulte também
Referência
Cláusula Select (Visual Basic)
A partir da cláusula (Visual Basic)
Conceitos
Introdução ao LINQ no Visual Basic