# Placeholder: Database Section

**URL:** <https://forum.alumio.com/t/placeholder-database-section/602>\
**Category:** Data Transformers\
**Created:** [May 19, 2023, 5:06pm UTC](https://forum.alumio.com/t/placeholder-database-section/602 "2023-05-19T17:06:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![abubakar](https://forum.alumio.com/letter_avatar_proxy/v4/letter/a/8491ac/32.png) [@abubakar](https://forum.alumio.com/u/abubakar)\
**Post date:** [May 19, 2023, 5:06pm UTC](https://forum.alumio.com/t/placeholder-database-section/602/1 "2023-05-19T17:06:48Z")

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Hello @Gugi , Inquiry about the usage of placeholders in the database data transformer, I’m exploring the database data transformer and would like to understand how placeholders can be used. Could you provide guidance or examples on using placeholders effectively for dynamic value replacement in queries or transformations because i need for a particular logic in my current project. And see in the image below within the **Destination input area** , i want to update the object in the customers(object)

 ![Screenshot 2023-05-19 at 18.04.57](https://alumio-forum.s3.dualstack.eu-central-1.amazonaws.com/uploads/original/1X/28a3da2b0ce9b464897685193d985832efe459b4.png)

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**Author:** ![Gugi](https://forum.alumio.com/user_avatar/forum.alumio.com/gugi/32/236_2.png) [@Gugi](https://forum.alumio.com/u/Gugi)\
**Post date:** [May 23, 2023, 12:43pm UTC](https://forum.alumio.com/t/placeholder-database-section/602/2 "2023-05-23T12:43:45Z")

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Hi @abubakar

The **Source** field should be filled in with the path to the data in the entity that we want to update to the storage. While the **Destination** field should be filled in with the path to the property in the storage entity that needs to be updated. Please see the below example.

For example, we have a storage that contains the below storage entity with the identifier `123`.

```auto
{
  "id": "123"
  "foo": "bar"
}

```

Then, we have the below entity and we want to update the value of the `foo` property in the above storage entity with a value of the `result.123.foo` property of the below entity.

```auto
{
  "identifier": "123",
  "result": {
    "123": {
      "foo": "baz"
    },
    "456": {
      "foo": "bar"
    }
  }

```

We can see that the path to the `foo` property belongs to an object with the key `123`. Let’s say each key of the `result` property represents the storage entity identifier in the storage. In this case, we should set the **Source** field dynamically with the help of the `&{}` placeholder, such as below.

 ![image](https://alumio-forum.s3.dualstack.eu-central-1.amazonaws.com/uploads/original/1X/dfd7e8ec3bece6683c5b19d8ff434557bcc40e12.png)

You can do the same way in the **Destination** field if you want to update a property with a dynamic path inside a storage entity.

I hope our explanation is clear to you. Feel free to let me know if you have any questions.