Add filter data descriptions, Fluent interface and LINQ

source/includes/api-details/cpp/crud/read-filter-or-query-objects-description.rst

@@ -0,0 +1,11 @@
+To filter data, call the ``.where()`` function on a collection with a valid
+query. Currently, C++ supports only a subset of RQL operators.
+
+Supported Query Operators
+`````````````````````````
+
+C++ supports the following query operators:
+
+- Equality (``==``, ``!=``)
+- Greater than/less than (``>``, ``>=``, ``<``, ``<=``)
+- Compound queries (``||``, ``&&``)

source/includes/api-details/csharp/crud/read-filter-or-query-objects-description.rst

@@ -0,0 +1,38 @@
+To query, filter, and sort data in the database, use the SDK query engine. 
+There are two ways to use the query engine with C#:
+
+- :ref:`LINQ Syntax <sdks-dotnet-linq>`
+- :ref:`Realm Query Language (RQL) <realm-query-language>`
+
+Use LINQ syntax for querying when possible, as it provides compile-time checks
+for queries and aligns with .NET conventions.
+
+Filter Data with LINQ
+`````````````````````
+
+To filter data with LINQ syntax, call the :dotnet-sdk:`Where()
+<linqsupport.html#restriction-operators>` operator with a
+:dotnet-sdk:`Predicate <linqsupport.html#predicate-operations>` that describes
+the subset of data you want to access.
+
+.. literalinclude:: /examples/generated/dotnet/QueryEngineExamples.snippet.logical.cs
+   :language: csharp
+
+Filter Data with RQL
+````````````````````
+
+You can also use the :ref:`Realm Query Language <realm-query-language>` (RQL) 
+to query realms. RQL is a string-based query language used to access the query 
+engine. When using RQL, you use the 
+:dotnet-sdk:`Filter() <reference/Realms.CollectionExtensions.html?q=Filter>`
+method: 
+
+.. literalinclude:: /examples/generated/dotnet/QueryEngineExamples.snippet.rql.cs
+    :language: csharp
+
+.. important::
+
+   Because :ref:`LINQ <sdks-dotnet-linq>` provides compile-time error checking 
+   of queries, you should use it instead of RQL in most cases. If you require 
+   features beyond LINQ's current capabilities, such as using 
+   :ref:`aggregation <rql-aggregate-operators>`, use RQL.

source/includes/api-details/dart/crud/read-filter-or-query-objects-description.rst

@@ -0,0 +1,8 @@
+Filter a collection to retrieve a specific segment of objects with the
+:flutter-sdk:`Realm.query() <realm/Realm/query.html>` method. In the
+``query()`` method's argument, use RQL to perform filtering.
+
+.. literalinclude:: /examples/generated/flutter/read_write_data_test.snippet.filter.dart
+   :language: dart
+
+You can use iterable arguments in your filter.

source/includes/api-details/java/crud/read-filter-or-query-objects-java-description.rst

@@ -0,0 +1,32 @@
+In Java, you can filter objects with either the Fluent interface or RQL.
+
+Filter Data with Fluent Interface
+`````````````````````````````````
+
+To filter data with the Fluent interface, filter data with a
+:java-sdk:`RealmQuery <io/realm/RealmQuery.html>`. For more details, refer
+to :ref:`Fluent interface <sdks-java-filter-data>`.
+
+In the following example, we use the Fluent interface comparison operators to:
+
+- Find high priority tasks by comparing the value of the ``priority`` property value with a threshold number, above which priority can be considered high.
+- Find just-started or short-running tasks by seeing if the ``progressMinutes`` property falls within a certain range.
+- Find unassigned tasks by finding tasks where the ``assignee`` property is equal to null.
+- Find tasks assigned to specific teammates Ali or Jamie by seeing if the ``assignee`` property is in a list of names.
+
+.. literalinclude:: /examples/generated/java/sync/ReadsTest.snippet.filter-results.java
+   :language: java
+   :copyable: false
+
+Filter Data with RQL
+````````````````````
+
+To filter data with RQL, use :java-sdk:`RealmQuery.rawPredicate()
+<io/realm/RealmQuery.html#rawPredicate-java.lang.String->`.
+For more information about syntax, usage and limitations,
+refer to the :ref:`Realm Query Language reference <realm-query-language>`.
+
+RQL can use either the class and property names defined in your SDK model
+classes or the internal names defined with ``@RealmField``. You can combine
+raw predicates with other raw predicates or type-safe predicates created with
+``RealmQuery``.

source/includes/api-details/java/crud/read-filter-or-query-objects-kotlin-description.rst

@@ -0,0 +1,33 @@
+In Java or Kotlin (Java SDK), you can filter objects with either the
+Fluent interface or RQL.
+
+Filter Data with Fluent Interface
+`````````````````````````````````
+
+To filter data with the Fluent interface, filter data with a
+:java-sdk:`RealmQuery <io/realm/RealmQuery.html>`. For more details, refer
+to :ref:`Fluent interface <sdks-java-filter-data>`.
+
+In the following example, we use the Fluent interface comparison operators to:
+
+- Find high priority tasks by comparing the value of the ``priority`` property value with a threshold number, above which priority can be considered high.
+- Find just-started or short-running tasks by seeing if the ``progressMinutes`` property falls within a certain range.
+- Find unassigned tasks by finding tasks where the ``assignee`` property is equal to null.
+- Find tasks assigned to specific teammates Ali or Jamie by seeing if the ``assignee`` property is in a list of names.
+
+.. literalinclude:: /examples/generated/java/sync/ReadsTest.snippet.filter-results.kt
+   :language: kotlin
+   :copyable: false
+
+Filter Data with RQL
+````````````````````
+
+To filter data with RQL, use :java-sdk:`RealmQuery.rawPredicate()
+<io/realm/RealmQuery.html#rawPredicate-java.lang.String->`.
+For more information about syntax, usage and limitations,
+refer to the :ref:`Realm Query Language reference <realm-query-language>`.
+
+RQL can use either the class and property names defined in your SDK model
+classes or the internal names defined with ``@RealmField``. You can combine
+raw predicates with other raw predicates or type-safe predicates created with
+``RealmQuery``.

source/includes/api-details/javascript/crud/read-filter-or-query-objects-js-ts-description.rst

@@ -0,0 +1,10 @@
+To filter a query, call :js-sdk:`filtered()
+<classes/Results.html#filtered>` on the query results collection.
+Pass a Realm Query Language query as argument to ``filtered()``.
+
+In the following example, we use RQL comparison operators to:
+
+- Find high priority tasks by comparing the value of the ``priority`` property
+  value with a threshold number, above which priority can be considered high.
+- Find just-started or short-running tasks by seeing if the ``progressMinutes``
+  property falls within a certain range.

source/includes/api-details/kotlin/crud/read-filter-or-query-objects-description.rst

@@ -0,0 +1,6 @@
+To filter by property, you can pass Realm Query Language (RQL) filters and 
+operators, use Kotlin's built-in extension methods or the SDK's convenience 
+methods, or use a combination.
+
+In the following example, we query a ``Frog`` object type and filter by the 
+``name`` property.

source/includes/api-details/objectivec/crud/read-filter-or-query-objects-description.rst

@@ -0,0 +1,6 @@
+To filter results in Objective-C, call :objc-sdk:`-[RLMResults objectsWhere:]
+<Classes/RLMResults.html#/c:objc(cs)RLMResults(im)objectsWhere:>`
+with a query predicate.
+
+For more details about the supported operators available for Objective-C
+queries, refer to :ref:`sdks-nspredicate-query`.

source/includes/api-details/swift/crud/read-filter-or-query-objects-description.rst

@@ -0,0 +1,29 @@
+Swift has its own query APIs that use either the type-safe ``where`` syntax,
+or a string ``NSPredicate`` query. For more details about the supported
+operators available for Swift queries, refer to :ref:`sdks-filter-data-swift`.
+
+Type-Safe Queries
+`````````````````
+
+To use the :ref:`Realm Swift Query API <ios-realm-swift-query-api>`, call
+:swift-sdk:`.where <Structs/Query.html>` with a closure that contains a query
+expression as an argument.
+
+This query API provides compile-time type-safe query checking. Prefer using
+this API over the older string-based ``NSPredicate`` API.
+
+.. literalinclude:: /examples/generated/code/start/ReadRealmObjects.snippet.where.swift
+   :language: swift
+
+NSPredicate Queries
+```````````````````
+
+To filter with the older string-based ``NSPredicate`` API, call
+:swift-sdk:`Results.filter(_:)
+<Structs/Results.html#/s:10RealmSwift7ResultsV6filteryACyxGSo11NSPredicateCF>`
+with a query predicate.
+
+Prefer using the type-safe query API unless you are using an SDK version
+older than 10.19.0. The string-based ``NSPredicate`` query API does not provide
+compile-time checking for valid query syntax, and may crash at runtime with
+an invalid ``NSPredicate``.

source/includes/sdk-examples/crud/read-filter-or-query-objects.rst

@@ -0,0 +1,63 @@
+.. tabs-drivers::
+
+   tabs:
+     - id: cpp-sdk
+       content: |
+
+         .. literalinclude:: /examples/generated/cpp/crud.snippet.filter-using-type-safe-query.cpp
+            :language: cpp
+
+     - id: csharp
+       content: |
+
+         .. literalinclude:: /examples/generated/dotnet/QueryEngineExamples.snippet.rql.cs
+            :language: csharp
+
+     - id: dart
+       content: |
+
+         .. literalinclude:: /examples/generated/flutter/read_write_data_test.snippet.filter-iterable.dart
+            :language: dart
+
+     - id: java
+       content: |
+
+         .. literalinclude:: /examples/generated/java/local/FilterDataTest.snippet.realm-query-language.java
+            :language: java
+
+     - id: java-kotlin
+       content: |
+
+         .. literalinclude:: /examples/generated/java/local/FilterDataTest.snippet.realm-query-language.kt
+            :language: kotlin
+
+     - id: javascript
+       content: |
+
+         .. literalinclude:: /examples/generated/node/read-and-write-data.snippet.read-and-write-filter-queries.js
+            :language: javascript
+
+     - id: kotlin
+       content: |
+
+         .. literalinclude:: /examples/generated/kotlin/ReadTest.snippet.query-by-property.kt
+            :language: kotlin
+
+     - id: objectivec
+       content: |
+
+         .. literalinclude:: /examples/generated/code/start/ReadWriteData.snippet.filter.m
+            :language: objectivec
+
+     - id: swift
+       content: |
+
+         .. literalinclude:: /examples/generated/code/start/ReadRealmObjects.snippet.filter.swift
+            :language: swift
+
+     - id: typescript
+       content: |
+
+         .. literalinclude::  /examples/MissingPlaceholders/example.ts
+            :language: typescript
+            :copyable: false

source/sdk/crud/query-engines.txt

@@ -15,5 +15,5 @@ query engines:
 
 - :ref:`realm-query-language`
 - :ref:`java-filter-data`
-- :ref:`dotnet-linq`
+- :ref:`sdks-dotnet-linq`
 - :ref:`sdks-filter-data-swift`