DatabaseQueryFilter

Description

The DatabaseQueryFilter object represents a query filter used in DatabaseQuery objects. Each filter consists of a set of DatabaseQueryWhere objects which are combined using logical OR. This means that one of the defined WHERE conditions have to match to make the whole filter match for a particular row.

› Inherits:: Object

Overview

Properties

Methods

Signals

Properties

where

This property holds one or multiple DatabaseQueryWhere instances or references to them used to create an SQL query for this filter.

› Type:: List<DatabaseQueryWhere>
› Signal:: whereChanged()
› Attributes:: Readonly

Signals

whereDataChanged(SignedInteger index)

This signal is emitted whenever the List.dataChanged() signal is emitted, i.e. the item at index in the where list itself emitted the dataChanged() signal.

Example

import InCore.Foundation 2.5
import InCore.Database 2.5

Application {

    LocalDatabase {
        id: exampleDatabase

        DatabaseTable {
            id: exampleTable

            DateTime { id: date }
            Measurement { id: temperature1 }
            Measurement { id: temperature2 }

            queries: [
                DatabaseQuery {
                    id: exampleQuery
                    DatabaseQueryFilter {
                        DatabaseQueryWhere { key: temperature1; operation: DatabaseQueryWhere.GreaterThan; value: 20 }
                        DatabaseQueryWhere { key: temperature2; operation: DatabaseQueryWhere.LessThan; value: 30 }
                    }

                    onResultsChanged: console.log(toJson(results))
                }
            ]
        }
    }

    Timer {
        onTriggered: {
            temperature1.data = 25 - Math.random() * 20
            temperature2.data = 25 + Math.random() * 20
            exampleTable.submit()
            exampleQuery.execute()
        }
    }

    onCompleted: exampleTable.drop()
}