remove (Function)

Function returns the updated map after removing the element with the specified key.

Syntax

<OBJECT> map:remove(<OBJECT> map, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key)

Query Parameters

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map that needs to be updated.		OBJECT	No	Yes
key	The key of the element that needs to removed.		OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes

Example 1

map:remove(stockDetails, 1234)

The map:remove(stockDetails, 1234) function operates on the stockDetails map, targeting the key 1234. If the key 1234 exists in the stockDetails map, it removes the corresponding key-value pair. The updated stockDetails map, now without the key 1234, is returned.

Example 2

CREATE STREAM StockInput (symbol string, price float, volume int, stockDetails object);
CREATE SINK STREAM UpdatedStockDetails (stockDetails object);

@info(name = 'RemoveStock')
INSERT INTO UpdatedStockDetails
SELECT map:remove(stockDetails, symbol) AS stockDetails
FROM StockInput;

In this stream worker example, two streams are created: StockInput and UpdatedStockDetails. The StockInput stream serves as the input, comprising of stock details such as symbol, price, volume, and the stockDetails map.

The RemoveStock query processes events from the StockInput stream, invoking the map:remove(stockDetails, symbol) function. This function attempts to locate the stock symbol within the stockDetails map. If the symbol is present, the corresponding key-value pair is removed.

The outcome is an updated stockDetails map, which no longer includes the stock details corresponding to the symbol from the StockInput stream event. This updated map is then inserted into the UpdatedStockDetails stream.

Through this mechanism, stockDetails in the UpdatedStockDetails stream evolves by removing specific stock details from StockInput, maintaining a dynamic map based on the incoming stream events.