replaceAll (Function)
Function returns the updated map after replacing all the key-value pairs from another map, if keys are present.
Syntax
<OBJECT> map:replaceAll(<OBJECT> to.map, <OBJECT> from.map)
Query Parameters
| Name | Description | Default Value | Possible Data Types | Optional | Dynamic |
|---|---|---|---|---|---|
| to.map | The map into which the key-values need to copied. | OBJECT | No | Yes | |
| from.map | The map from which the key-values are copied. | OBJECT | No | Yes |
Example 1
map:replaceAll(toMap, fromMap)
The map:replaceAll(toMap, fromMap) function operates on two input maps: toMap and fromMap. In the given example, toMap initially holds the key-value pairs (symbol: gdn), (volume: 100). Meanwhile, fromMap carries the pairs (symbol: IBM), (price : 12). This function performs an operation that replaces all the values in toMap with the corresponding values from fromMap when the keys match in both maps. The outcome of this example would be an updated toMap that holds the pairs (symbol: IBM), (volume: 100).
Example 2
CREATE STREAM StockInput (symbol string, price float, volume int, stockDetails object, newDetails object);
CREATE SINK STREAM UpdatedStockDetails (stockDetails object);
@info(name = 'ReplaceStockDetails')
INSERT INTO UpdatedStockDetails
SELECT map:replaceAll(stockDetails, newDetails) AS stockDetails
FROM StockInput;
In this stream worker example, the StockInput stream carries symbol, price, volume, along with two maps - stockDetails and newDetails. The stockDetails map represents the current state of various stock symbols and their associated details, while the newDetails map holds the new details that should replace the existing ones in stockDetails.
The ReplaceStockDetails query operates on events from the StockInput stream. It uses the map:replaceAll(stockDetails, newDetails) function to replace all the existing key-value pairs in the stockDetails map with the key-value pairs from the newDetails map.
The resultant stockDetails map, which reflects the updated stock details, is then inserted into the UpdatedStockDetails stream. This ensures that the stockDetails map is continually refreshed with the latest stock details from the StockInput stream.