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Overwrite Current Value

Description

This operation overwrites the value of a key.

It is almost identical to Set Value By Key Name operation, but provides an additional parameter to control the overwrite process more flexibly.

Method

Backendless.Hive(hiveName).MapStore(keyName).setWithOverwrite(key, value, overwrite): Promise<boolean>;

where:

Argument                Description
hiveName Name of a hive where the operation is performed. String value.
keyName Key name identifying a map. String value.
key Name of the key whose value is replaced. String value.
value New value for the key. Can be of any data type.
overwrite When set to true, forces the rename operation and name overwrite. Boolean value.

Return Value

The return value depends on the operation behavior:

When the overwrite parameter is set to true:

Scenario 1: If the specified key is found, the operation overwrites the value and returns false. The false is returned to indicate that the new key-value pair was not created, but only the existing key-value pair was updated.

Scenario 2: If the specified key is not found, then the operation creates a new value pair and returns true.

When the overwrite parameter is set to false:

Scenario 1: If the specified key is found, the operation does not overwrite the value, but only returns false indicating that the value was not overwritten and the new-key value pair was not created.

Scenario 2: If the specified key is not found, then the operation creates a new value pair and returns true.

Example

The example below overwrites the current value of the 'Oranges' key with a new value 1.29. The invocation returns false indicating that this value is updated. As you can see, the overwrite parameter is set to true, hence the operation overwrites the value.

await Backendless.Hive('groceryStore').MapStore('fruits').setWithOverwrite('Oranges', 1.29, true)

where:

Argument                Description
'groceryStore' Name of a hive where the operation is performed.
'fruits' Key name identifying a map.

Codeless Reference

map_api_set_value_with_overwrite

where:

Argument                Description
hive name Name of a hive where the operation is performed.
key name Key name identifying a map.
object key name Key name identifying a key-value pair.
value A value for a key.
overwrite When set to true, forces the rename operation and name overwrite.

The return value depends on the operation behavior:

When the overwrite parameter is set to true:

Scenario 1: If the specified key is found, the operation overwrites the value and returns false. The false is returned to indicate that the new key-value pair was not created, but only the existing key-value pair was updated.

Scenario 2: If the specified key is not found, then the operation creates a new value pair and returns true.

When the overwrite parameter is set to false:

Scenario 1: If the specified key is found, the operation does not overwrite the value, but only returns false indicating that the value was not overwritten and the new-key value pair was not created.

Scenario 2: If the specified key is not found, then the operation creates a new value pair and returns true.

Consider the following Map storage:
map_apI_example_map_store

The example below overwrites the current value of the "Oranges" key with a new value 1.29.

map_example_api_set_value_with_overwrite

The map will look as shown below after the Codeless logic runs:
map_apI_example_map_store_5