ODataQuery<T> Class
Builds the OData query options $filter, $expand, $orderby, $skip, $top, $count and $apply for the entity set of T from lambda expressions, with the method names of Entity Framework Core. Every method returns a new query and leaves the one it was called on unchanged. A value a lambda captures is read when the method is called. Pass the query to LoadDataArgs) to get the request URI.
Inheritance
Object
ODataQuery<T>
Namespace: Radzen
Assembly: Radzen.Blazor.dll
Syntax
public class ODataQuery<T>Type Parameters
| Name | Description |
|---|---|
| T | The entity type of the entity set. |
Examples
var query = new ODataQuery<Ticket>()
.Where(ticket => ticket.Status == TicketStatus.Open && ticket.Subject.Contains(search))
.Include(ticket => ticket.Team).ThenInclude(team => team.Schedule)
.OrderByDescending(ticket => ticket.CreatedAt)
.Take(10);
var uri = new Uri(baseUri, "Tickets").GetODataUri(query);Constructors
ODataQuery<T>linkLink to this section
Initializes a new query that has no options.
Declaration
public ODataQuery<T>()Methods
GroupBylinkLink to this section
Groups the entities by keySelector for a Select of the group keys and aggregates, translated to $apply=groupby(...), or to $apply=aggregate(...) when the key is a constant such as 1, which puts every entity in one group. Every Where before it becomes a filter(...) transformation that runs before the grouping.
Declaration
public GroupedODataQuery<T, TKey> GroupBy(Expressions.Expression<Func<T, TKey>> keySelector)Parameters
| Type | Name | Description |
|---|---|---|
| Expressions.Expression<Func<T, TKey>> | keySelector | The key, e.g. license => license.Currency, license => new { license.Currency, license.Country } or license => 1. |
Returns
| Type | Description |
|---|---|
| GroupedODataQuery<T, TKey> | A grouping on which Select sets the result. |
IncludelinkLink to this section
Expands the navigation property that navigation selects, translated to $expand. A path such as ticket => ticket.Team.Schedule expands each level, and a collection can be filtered, ordered and paged with Where, OrderBy, OrderByDescending, ThenBy, ThenByDescending, Skip and Take, e.g. ticket => ticket.Comments.OrderByDescending(comment => comment.CreatedAt).Take(3).
Declaration
public IncludableODataQuery<T, TProperty> Include(Expressions.Expression<Func<T, TProperty>> navigation)Parameters
| Type | Name | Description |
|---|---|---|
| Expressions.Expression<Func<T, TProperty>> | navigation | The navigation property. |
Returns
| Type | Description |
|---|---|
| IncludableODataQuery<T, TProperty> | A new query to which Func{``1,``2}}) adds the next level. |
OrderBylinkLink to this section
Orders the entities by keySelector ascending, translated to $orderby. Replaces any earlier ordering.
Declaration
public OrderedODataQuery<T> OrderBy(Expressions.Expression<Func<T, TKey>> keySelector)Parameters
| Type | Name | Description |
|---|---|---|
| Expressions.Expression<Func<T, TKey>> | keySelector | The key, e.g. ticket => ticket.Team.Name. |
Returns
| Type | Description |
|---|---|
| OrderedODataQuery<T> | A new query to which ThenBy adds the next key. |
OrderByDescendinglinkLink to this section
Orders the entities by keySelector descending, translated to $orderby. Replaces any earlier ordering.
Declaration
public OrderedODataQuery<T> OrderByDescending(Expressions.Expression<Func<T, TKey>> keySelector)Parameters
| Type | Name | Description |
|---|---|---|
| Expressions.Expression<Func<T, TKey>> | keySelector | The key, e.g. ticket => ticket.CreatedAt. |
Returns
| Type | Description |
|---|---|
| OrderedODataQuery<T> | A new query to which ThenBy adds the next key. |
SkiplinkLink to this section
Skips count entities, translated to $skip. Call it once, before Int32).
Declaration
public ODataQuery<T> Skip(int count)Parameters
| Type | Name | Description |
|---|---|---|
| int | count | The number of entities to skip. |
Returns
| Type | Description |
|---|---|
| ODataQuery<T> | A new query with $skip. |
TakelinkLink to this section
Takes at most count entities, translated to $top. Call it once.
Declaration
public ODataQuery<T> Take(int count)Parameters
| Type | Name | Description |
|---|---|---|
| int | count | The number of entities to return. |
Returns
| Type | Description |
|---|---|
| ODataQuery<T> | A new query with $top. |
ToQueryStringlinkLink to this section
Returns the query options with each value escaped once with String), e.g. $filter=Name%20eq%20%27O%27%27Brien%27&$top=10.
Declaration
public string ToQueryString()Returns
| Type | Description |
|---|---|
| string | The query string without the leading question mark, or an empty string when the query has no options. |
ToStringlinkLink to this section
Returns the query options unescaped, e.g. $filter=Name eq 'O''Brien'&$top=10.
Declaration
public override string ToString()Returns
| Type | Description |
|---|---|
| string | The readable query options. |
WherelinkLink to this section
Filters the entities with predicate, translated to $filter. Repeated calls combine with and.
Declaration
public ODataQuery<T> Where(Expressions.Expression<Func<T, bool>> predicate)Parameters
| Type | Name | Description |
|---|---|---|
| Expressions.Expression<Func<T, bool>> | predicate | The condition, e.g. ticket => ticket.Status == TicketStatus.Open. |
Returns
| Type | Description |
|---|---|
| ODataQuery<T> | A new query with the filter added. |
WithCountlinkLink to this section
Requests the total count of the filtered entities, translated to $count=true.
Declaration
public ODataQuery<T> WithCount()Returns
| Type | Description |
|---|---|
| ODataQuery<T> | A new query with $count=true. |