note

VeloxDB is still in beta and APIs are subject to change. We are in the process of completing the documentation, so some sections may be incomplete or empty at this time.

Class DatabaseArray<T>

Represents a strongly typed array of simple types.

Inheritance

System.Object

DatabaseArray

DatabaseArray<T>

Implements

System.Collections.Generic.IList<T>

System.Collections.Generic.ICollection<T>

System.Collections.Generic.IEnumerable<T>

System.Collections.IEnumerable

Namespace: VeloxDB.ObjectInterface

Assembly: vlxdb.dll

Syntax

public abstract class DatabaseArray<T> : DatabaseArray

Type Parameters

Name	Description
T	The type of elements in the array.

Remarks

VeloxDB allows you to specify an array like collection. DatabaseArray<T> can only hold simple types, if you need an array of references to other DatabaseObjects, use ReferenceArray<T>.

DatabaseArray<T> is backed by an array. Array's size is initially set to capacity. As long as the capacity is larger than the length of the array Add is constant time operation (O(1)). When there is no more space in the backing array new array is allocated. The new array is twice the size of the previous one. Contents of the old array are copied to the new array. This gives DatabaseArray<T> amortized constant time adds, constant time direct access and linear remove.

Examples

The following example demonstrates how to declare a DatabaseArray<T> property.

[DatabaseClass]
public abstract class WeatherStation : DatabaseObject
{
    [DatabaseProperty]
    public abstract double Lat { get; set; }

    [DatabaseProperty]
    public abstract double Long { get; set; }

    [DatabaseProperty]
    public abstract DatabaseArray<double> Temperature { get; set; }

    [DatabaseProperty]
    public abstract DatabaseArray<DateTime> Dates { get; set; }
}

The following example demonstrates how to use a DatabaseArray<T>.

[DbAPIOperation]
public void CreateTestStation(ObjectModel om)
{
    WeatherStation ws = om.CreateObject<WeatherStation>();

    // Create an empty array
    ws.Dates = DatabaseArray<DateTime>.Create(4);

    // Add new dates to the end
    ws.Dates.Add(new DateTime(2022, 7, 1));
    ws.Dates.Add(new DateTime(2022, 7, 2));
    ws.Dates.Add(new DateTime(2022, 7, 3));
    ws.Dates.Add(new DateTime(2022, 7, 4));

    // Create an array from an existing collection
    ws.Temperature = DatabaseArray<double>.Create(new double[] { 33, 39, 41, 34 });

    // Remove by value
    ws.Temperature.Remove(41);

    // Remove using index
    ws.Temperature.RemoveAt(2);

    // Clear
    ws.Temperature.Clear();
    ws.Dates.Clear();
}

Properties

Count

Gets the number of items contained in the DatabaseArray<T>.

Declaration

public int Count { get; }

Property Value

Type	Description
System.Int32

IsReadOnly

Gets if the DatabaseArray<T> is Readonly. Always returns false.

Declaration

public bool IsReadOnly { get; }

Property Value

Type	Description
System.Boolean

Item[Int32]

Index accessor.

Declaration

public abstract T this[int index] { get; set; }

Parameters

Type	Name	Description
System.Int32	index	Index of the item to get.

Property Value

Type	Description
T	Requested item.

Exceptions

Type	Condition
System.IndexOutOfRangeException	If index is less than 0 or greater than Count
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Methods

Add(T)

Add an item to the end of the DatabaseArray<T>.

Declaration

public void Add(T item)

Parameters

Type	Name	Description
T	item	The item to be added to the end of the DatabaseArray<T>.

Exceptions

Type	Condition
System.InvalidOperationException	If the added item would cause Count to exceed int.MaxValue or If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

AddRange(IEnumerable<T>)

Adds the elements of the specified collection to the end of the DatabaseArray<T>.

Declaration

public void AddRange(IEnumerable<T> collection)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<T>	collection	Collection whose elements will be added.

Exceptions

Type	Condition
System.ArgumentNullException	collection is null.
System.InvalidOperationException	If the adding collection items would cause Count to exceed int.MaxValue or If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Clear()

Clears the DatabaseArray<T>.

Declaration

public void Clear()

Exceptions

Type	Condition
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Contains(T)

Determines if an item is in the DatabaseArray<T>.

Declaration

public bool Contains(T item)

Parameters

Type	Name	Description
T	item	The item to locate in the DatabaseArray<T>.

Returns

Type	Description
System.Boolean	true if item is present in the DatabaseArray<T>, false if not.

Exceptions

Type	Condition
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

CopyTo(T[], Int32)

Copies all items from the DatabaseArray<T> to the given array, starting at the specified index of the target array.

Declaration

public void CopyTo(T[] array, int arrayIndex)

Parameters

Type	Name	Description
T[]	array	Destination array.
System.Int32	arrayIndex	Zero based index in array at which copying begins.

Exceptions

Type	Condition
System.ArgumentNullException	array is null.
System.ArgumentException	There is not enough space in array to accommodate all the items.
System.ArgumentOutOfRangeException	arrayIndex is less than 0.
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Create()

Creates a new empty instance of the DatabaseArray<T>.

Declaration

public static DatabaseArray<T> Create()

Returns

Type	Description
DatabaseArray<T>	Created DatabaseArray<T>

Create(IEnumerable<T>)

Creates a new instance of the DatabaseArray<T> that contains elements copied from the supplied collection.

Declaration

public static DatabaseArray<T> Create(IEnumerable<T> collection)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<T>	collection	The collection whose elements are to be copied.

Returns

Type	Description
DatabaseArray<T>	Created DatabaseArray<T>

Exceptions

Type	Condition
System.ArgumentNullException	collection is null.

Create(Int32)

Creates a new empty instance of the DatabaseArray<T>. With specified capacity.

Declaration

public static DatabaseArray<T> Create(int capacity)

Parameters

Type	Name	Description
System.Int32	capacity	Initial capacity. The initial size of the backing array.

Returns

Type	Description
DatabaseArray<T>	Created DatabaseArray<T>

GetEnumerator()

Returns an enumerator that iterates through DatabaseArray<T>.

Declaration

public IEnumerator<T> GetEnumerator()

Returns

Type	Description
System.Collections.Generic.IEnumerator<T>	An enumerator.

Remarks

If DatabaseArray<T> changes, enumerator is invalidated. Any attempts to use it after that will throw an System.InvalidOperationException.

Exceptions

Type	Condition
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

IndexOf(T)

Finds an item in the DatabaseArray<T> and returns its position.

Declaration

public int IndexOf(T item)

Parameters

Type	Name	Description
T	item	Item to find in DatabaseArray<T>.

Returns

Type	Description
System.Int32	If the element is found, it return the zero based index in DatabaseArray<T>, otherwise it returns -1.

Exceptions

Type	Condition
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Insert(Int32, T)

Inserts an item into DatabaseArray<T> at the specified position.

Declaration

public void Insert(int index, T item)

Parameters

Type	Name	Description
System.Int32	index	Zero based position at which to insert item.
T	item	The item to insert.

Exceptions

Type	Condition
System.ArgumentOutOfRangeException	If index is less than 0 or greater than Count
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Remove(T)

Remove the first occurrence of the item from the DatabaseArray<T>.

Declaration

public bool Remove(T item)

Parameters

Type	Name	Description
T	item	Item to be removed.

Returns

Type	Description
System.Boolean	true if item was removed, otherwise false.

Exceptions

Type	Condition
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

RemoveAt(Int32)

Remove an item at the given position.

Declaration

public void RemoveAt(int index)

Parameters

Type	Name	Description
System.Int32	index	Zero based index of an item to remove.

Exceptions

Type	Condition
System.ArgumentOutOfRangeException	If index is less than 0 or greater than Count
System.InvalidOperationException	If the parent object of the DatabaseArray<T> has been deleted or abandoned.
System.ObjectDisposedException	If the parent object of the DatabaseArray<T> has been disposed.

Implements

System.Collections.Generic.IList<>

System.Collections.Generic.ICollection<>

System.Collections.Generic.IEnumerable<>

System.Collections.IEnumerable

See Also

ReferenceArray<T>