Class QueryMethods

Provides methods that get translated into native Realm queries when using LINQ.

Inheritance

object

QueryMethods

Namespace: Realms

Assembly: Realm.dll

Syntax

public static class QueryMethods

Remarks

These methods don't have implementation and are only usable in a LINQ query performed on a Realm query result - e.g. the IQueryable returned by All<T>().

Methods

Contains(string?, string, StringComparison)

Returns a value indicating whether a specified substring occurs within this string.

Declaration

public static bool Contains(string? str, string value, StringComparison comparisonType)

Parameters

Type	Name	Description
string	str	The original string.
string	value	The string to seek.
StringComparison	comparisonType	One of the enumeration values that determines how this string and value are compared.

Returns

Type	Description
bool	true if the value parameter occurs within this string, or if value is the empty string (""); otherwise, false.

Exceptions

Type	Condition
ArgumentNullException	Thrown when str or value is null.
ArgumentException	Thrown when comparisonType is not a valid StringComparison value.

FullTextSearch(string?, string)

Performs a 'simple term' Full-Text search on a string property.

Declaration

public static bool FullTextSearch(string? str, string terms)

Parameters

Type	Name	Description
string	str	The string to compare against the terms.
string	terms	The terms to look for in str.

Returns

Type	Description
bool	true if the string matches the terms; false otherwise.

Remarks

When this method is used outside of a Realm query, a NotSupportedException will be thrown.

Examples

var matches = realm.All<Book>().Where(b => b.Summary.FullTextSearch("fantasy novel"));

GeoWithin(IEmbeddedObject?, GeoShapeBase)

Checks whether geoShape contains the point represented by an embedded object.

Declaration

public static bool GeoWithin(IEmbeddedObject? point, GeoShapeBase geoShape)

Parameters

Type	Name	Description
IEmbeddedObject	point	An embedded object that has the shape of a GeoJson point. It must have at least two fields - IList<double> coordinates and string type. The shape of the object will be verified at runtime.
GeoShapeBase	geoShape	One of GeoBox, GeoCircle, or GeoPolygon representing the shape that point will be checked against.

Returns

Type	Description
bool	true if point is contained in geoShape; false otherwise.

Examples

An example embedded object that can be used in geospatial queries is:

public partial class MyGeoPoint : IEmbeddedObject
{
    [MapTo("coordinates")]
    private IList<double> Coordinates { get; } = null!;

    [MapTo("type")]
    private string Type { get; set; } = "Point";

    public double Latitude => Coordinates.Count > 1 ? Coordinates[1] : throw new Exception($"Invalid coordinate array. Expected at least 2 elements, but got: {Coordinates.Count}");

    public double Longitude => Coordinates.Count > 1 ? Coordinates[0] : throw new Exception($"Invalid coordinate array. Expected at least 2 elements, but got: {Coordinates.Count}");

    public MyGeoPoint(double latitude, double longitude)
    {
        Coordinates.Add(longitude);
        Coordinates.Add(latitude);
    }
}

Note that if you're using Sync, the name of the embedded object type must match exactly the title of the embedded object defined in the GeoJson Schema on the server.

Like(string?, string, bool)

Performs a 'like' comparison between the specified string and pattern.

Declaration

public static bool Like(string? str, string pattern, bool caseSensitive = true)

Parameters

Type	Name	Description
string	str	The string to compare against the pattern.
string	pattern	The pattern to compare against.
bool	caseSensitive	If set to true performs a case sensitive comparison.

Returns

Type	Description
bool	true if the string matches the pattern, false otherwise.

Remarks

? and are allowed where ? matches a single character and matches zero or more characters, such that ?bc* matches abcde and bbc, but does not match bcd.

This extension method can be used in LINQ queries against the IQueryable returned from All<T>(). If used outside of a query context, it will use a Regex to perform the comparison using the same rules.