> ## Documentation Index
> Fetch the complete documentation index at: https://docs.activeviam.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Incremental Refresh

Incremental refresh is called through the Application API.
It is important to note that all table names and field names are those from the DirectQuery local schema.

```java theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
final TableUpdateDetail tableUpdateDetail =
    TableUpdateDetail.create(
        "SALES",
        ChangeType.ADD_ROWS,
        ConditionFactory.equal("DATE", LocalDate.of(2022, 4, 16)));
app.refresh(ChangeDescription.create(List.of(tableUpdateDetail)));
```

Here some change examples with their change description.

## Multi table add rows

In this case, we have added some new sales for the seller google.\
We have also added a new product.
`sales` has a many-to-one relationship with `product`.

**Table `sales` changes**

| date           | product | seller     | quantity |
| -------------- | ------- | ---------- | -------- |
| 2024-01-01     | P1      | microsoft  | 20       |
| 2024-01-01     | P2      | amazon     | 30       |
| 2024-01-01     | P2      | amazon     | 20       |
| **2024-01-01** | **P1**  | **google** | **20**   |
| **2024-01-01** | **P2**  | **google** | **30**   |
| **2024-01-01** | **P3**  | **google** | **20**   |

**Table `products` changes**

| date           | product | quantity |
| -------------- | ------- | -------- |
| 2024-01-01     | P1      | 10       |
| 2024-01-01     | P2      | 20       |
| **2024-01-01** | **P3**  | **30.0** |

**Change description**

| Table Update Detail | sales                   | products               |
| ------------------- | ----------------------- | ---------------------- |
| Change type         | ADD\_ROWS               | ADD\_ROWS              |
| Change Scope        | sales.seller = 'google' | product.product = 'P3' |

```java theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
final List<TableUpdateDetail> updateDetails =
    List.of(
        TableUpdateDetail.create(
            "SALES", ChangeType.ADD_ROWS, ConditionFactory.equal("SELLER", "google")),
        TableUpdateDetail.create(
            "PRODUCTS", ChangeType.ADD_ROWS, ConditionFactory.equal("PRODUCT", "P3")));
app.refresh(ChangeDescription.create(updateDetails));
```

## Multi table add rows using an unknown condition

In this case, we have added new rows in sales table.\
All these new sales has a new seller which has been added in users table.
`sales` has a many-to-one relationship with `users`.

**Table `sales` changes**

| date           | product | seller      | quantity |
| -------------- | ------- | ----------- | -------- |
| 2024-01-01     | P1      | microsoft   | 20       |
| 2024-01-01     | P2      | amazon      | 30       |
| 2024-01-01     | P2      | amazon      | 20       |
| **2024-01-02** | **P1**  | **google**  | **20**   |
| **2024-01-02** | **P2**  | **alibaba** | **30**   |
| **2024-01-02** | **P3**  | **ibm**     | **20**   |

**Table `users` changes**

| id          | warehouse |
| ----------- | --------- |
| microsoft   | nyo-1     |
| amazon      | chi-1     |
| **google**  | **tor-1** |
| **alibaba** | **bei-1** |
| **ibm**     | **par-1** |

This change can be expressed with this description which could be cumbersome to build because of the `IN` condition.

**Change description**

| Table Update Detail | sales                     | users                                   |
| ------------------- | ------------------------- | --------------------------------------- |
| Change type         | ADD\_ROWS                 | ADD\_ROWS                               |
| Change Scope        | sales.date = '2024-01-02' | users.id in ('google', 'alibaba','ibm') |

Here we managed to resolve a cumbersome condition looking at the data, but sometimes it is not possible to come up with a convenient condition.\
In this case you can use the unknown condition.

**Change description with an unknown condition**

| Table Update Detail | sales                     | users             |
| ------------------- | ------------------------- | ----------------- |
| Change type         | ADD\_ROWS                 | ADD\_ROWS         |
| Change Scope        | sales.date = '2024-01-02' | Unknown condition |

This solution could have adverse consequences.\
If you have defined a factless hierarchy on user table, the missing link with the fact table forbid us to use the sales
table scope.\
Connector will full refresh on this hierarchy stream.

```java theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
final List<TableUpdateDetail> updateDetails =
    List.of(
        TableUpdateDetail.create(
            "SALES",
            ChangeType.ADD_ROWS,
            ConditionFactory.equal("DATE", LocalDate.of(2024, 1, 2))),
        TableUpdateDetail.create("PRODUCTS", ChangeType.ADD_ROWS, ConditionFactory.unknown()));
app.refresh(ChangeDescription.create(updateDetails));
```