replace (Function)

Function returns the updated map after replacing the given key-value pair only if key is present.

Syntax

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

Query Parameters

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map to which the key-value should be replaced.		OBJECT	No	Yes
key	The key to be replaced.		INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes
value	The value to be replaced.		INT LONG FLOAT DOUBLE BOOL STRING	No	Yes

Example 1

map:replace(stockDetails , 1234 , 'IBM')

The map:replace(stockDetails, 1234, 'IBM') function is designed to operate on the stockDetails map, targeting the key 1234. If this key is present within the map, the function will replace the corresponding value with 'IBM'. The resultant updated stockDetails map is then returned.

Example 2

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

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

In this stream worker example, the StockInput stream carries symbol, price, volume, and a stockDetails map. This map represents the current state of various stock symbols and their associated prices.

The UpdateStockDetails query takes events from the StockInput stream and applies the map:replace(stockDetails, symbol, price) function on each event to update the stockDetails map. If the symbol from the current event exists as a key in the stockDetails map, then its associated value (i.e., price) gets replaced with the price from the current event.

The resulting stockDetails map, reflecting the replaced price for the symbol in question, is sent to the UpdatedStockDetails stream. This ensures that the stockDetails map is consistently updated with the latest stock prices from the StockInput stream.