Interface IQuery

An interface representing a runnable query over a data source

Inherited Members

System.IDisposable.Dispose()

Namespace: Couchbase.Lite.Query

Assembly: Couchbase.Lite.dll

Syntax

public interface IQuery : IDisposable

Properties

Parameters

Gets or sets the parameter collection for this query so that parameters may be added for substitution into the query API (via Parameter(String))

Declaration

Parameters Parameters { get; set; }

Property Value

Type	Description
Parameters

Remarks

The returned collection is a copy, and must be reset onto the query instance. Doing so will trigger a re-run and update any listeners.

Methods

AddChangeListener(EventHandler<QueryChangedEventArgs>)

Adds a change listener to track when this query instance has a change in its results. Adding the first change listener will begin the live semantics.

Declaration

ListenerToken AddChangeListener(EventHandler<QueryChangedEventArgs> handler)

Parameters

Type	Name	Description
System.EventHandler<QueryChangedEventArgs>	handler	The handler to call when the query result set changes

Returns

Type	Description
ListenerToken	A token that can be used to remove the listener later

AddChangeListener(TaskScheduler, EventHandler<QueryChangedEventArgs>)

Adds a change listener to track when this query instance has a change in its results. Adding the first change listener will begin the live semantics.

Declaration

ListenerToken AddChangeListener(TaskScheduler scheduler, EventHandler<QueryChangedEventArgs> handler)

Parameters

Type	Name	Description
System.Threading.Tasks.TaskScheduler	scheduler	The scheduler to use when firing events
System.EventHandler<QueryChangedEventArgs>	handler	The handler to call when the query result set changes

Returns

Type	Description
ListenerToken	A token that can be used to remove the listener later

Execute()

Runs the query

Declaration

IResultSet Execute()

Returns

Type	Description
IResultSet	The results of running the query

Exceptions

Type	Condition
System.InvalidOperationException	Thrown if this query has no database to operate on, or if it is missing SELECT or FROM statements (unusual)

Explain()

Gets an explanation of what the query will do

Declaration

string Explain()

Returns

Type	Description
System.String	The explanation of the query

Exceptions

Type	Condition
System.ObjectDisposedException	Thrown if this method is called after disposal

RemoveChangeListener(ListenerToken)

Removes a changes listener based on the token that was received from AddChangeListener(TaskScheduler, EventHandler<QueryChangedEventArgs>)

Declaration

void RemoveChangeListener(ListenerToken token)

Parameters

Type	Name	Description
ListenerToken	token	The received token from adding the change listener