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).set(objKey, value, overwrite);
where:
| Argument | Description |
|---|---|
hiveName |
Name of a hive where the operation is performed. String value. |
keyName |
Key name identifying a map. String value. |
objKey |
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.
Backendless.Hive("groceryStore").MapStore("fruits").set("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¶
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:
The example below overwrites the current value of the "Oranges" key with a new value 1.29.
The map will look as shown below after the Codeless logic runs: