# system.kanoa.inventory.updateInventoryTransactionField(inventoryTransactionId, field, value, userId)

Updates a single named field on an existing inventory transaction to the given value. 
Unlike `addInventoryTransaction`, this function does **not** recompute or adjust the inventory balance � 
it is intended for correcting metadata (cost, references, notes) on a transaction after the fact, not for changing quantity or type. 
Use `addInventoryTransaction` for any change that should affect the inventory balance.

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### Parameters
**inventoryTransactionId** `Integer`: Id of inventory transaction to update<br />
**field** `String`: Valid options are `unitCost`, `assetId`, `supplierId`, `costCenterId`, `referenceType`, `referenceNumber`, `notes`<br />
**value:** `Object`: Value to update to<br />
**userId** `Integer`:Id of the user executing the function<br />

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### Returns
**# of records modified** `Integer`<br />
**message** `String` None if success<br />

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### Example
```python
inventoryTransactionId = 5821
field = 'unitCost'
value = 4.50
userId = system.kanoa.security.getIDPUserId({'userName': 'SYSTEM'})

recordsModified, message = system.kanoa.inventory.updateInventoryTransactionField(inventoryTransactionId, field, value, userId)
print recordsModified, message
```