DATASET

The DATASET object is implemented as a key-value store that is a simple NoSQL in memory database. The data is stored in memory as a linked list of data items where each item requires a unique 'key'. The 'value' data for each item can be plain text, JSON, XML, binary data, HTML, etc... The DATASET object has properties and methods that allow a PL/B program to maintain and manage program data items as needed for the application. The declaration syntax of a DATASET is as follows:

(1)	[label]	DATASET	[%\|^][(arraysize)]
(2)	[label]	DATASET	^,{target}
(3)	[label]	DATASET	^(arraysize),({target}),...,({target})

Where:

label

Optional. A Data Label.

Optional. Denotes the item as being GLOBAL.

arraysize

Required. An integer decimal constant, CONST variable, or EQUATEd value indicating the number of array items.

Optional. Denotes the item as being a POINTER.

target

Required. The name of a previously defined data item of the same type.

Flags Affected: NONE

Properties:

Properties are attributes of an object that define the object's characteristics or its behavior.

COUNT	Get the current number of data items.
DATAFILTER	Filter string.
DATATYPE	A type assigned to the items.
MAXITEMS	The maximum item count for the number of active items that can be added.
NULLSIZE	The text size to be used when an item is added with NULL input.
OBJECTID	The identification number associated with an object.
RUNNAME	The run-time name of the object.
USERDATA	Application specific data.

Methods:

Methods are encapsulated routines that act upon an object.

AddItem	Adds a data item.
DeleteAllItems	Deletes and frees memory for all data items.
DeleteItem	Finds and deletes a data item.
FindItem	Finds a data item using a key or index
GetItem	Finds a data item using a key or index and retrieves the associated data string.
Pop	Retrieves data items from a stack.
Push	Places data items onto a stack.
UpdateItem	Finds a data item using a key or index and updates the data for the data item.

Note the following:

The DATASET is supported in CREATE, GETPROP, and SETPROP instructions.
If the DATASET object is not created when a method is executed, it is implicitly created by the method. When the DATASET object is implicitly created, all of the properties for the object are set to their default states.