Daily DAX : Day 275 REMOVEFILTERS

 The **REMOVEFILTERS** function in Power BI DAX (Data Analysis Expressions) is used to remove filters from a specified table or column(s) in a calculation, allowing you to perform calculations on unfiltered data while retaining the context of other filters in the query. It is particularly useful in scenarios where you want to ignore specific filters applied by slicers, visuals, or other parts of the report to compute a value based on the entire dataset or a subset of it.

### Syntax

```dax

REMOVEFILTERS([<table> | <column>[, <column>[, ...]]])

```

- **table**: The name of the table from which filters should be removed.

- **column**: One or more columns from which filters should be removed. If no arguments are provided, it removes all filters from the current context.

### How It Works

- **REMOVEFILTERS** clears filters on the specified table or columns in the filter context of a DAX calculation.

- It is typically used within a **CALCULATE** or **CALCULATETABLE** function to modify the filter context for a specific measure or expression.

- It does not affect filters applied outside the specified table/columns, preserving other aspects of the filter context.

### Use Cases

1. **Calculating Totals Without Filters**:

   - When a report applies filters (e.g., via slicers or visuals), you may want to calculate a total or aggregate value for the entire dataset, ignoring those filters. For example, calculating the percentage of sales for a specific category relative to total sales across all categories.

   

2. **Comparing Filtered vs. Unfiltered Data**:

   - Useful for creating measures that compare filtered data (e.g., sales for a selected region) against unfiltered data (e.g., total sales across all regions).

3. **Ignoring Specific Filters**:

   - When you want to remove filters on specific columns (e.g., a date filter) but retain other filters (e.g., a product category filter).

4. **Dynamic Calculations**:

   - Helps create dynamic measures that adjust calculations based on the removal of specific filters, such as year-over-year comparisons ignoring certain slicer selections.

### Example

Suppose you have a table `Sales` with columns `Region`, `Product`, `SalesAmount`, and a slicer in your report filtering for `Region = "North"`. You want to calculate the percentage of sales for the selected region compared to total sales across all regions.

#### DAX Measure

```dax

Sales Percentage =

DIVIDE(

    SUM(Sales[SalesAmount]),

    CALCULATE(

        SUM(Sales[SalesAmount]),

        REMOVEFILTERS(Sales[Region])

    )

)

```

- **Explanation**:

  - The numerator (`SUM(Sales[SalesAmount])`) calculates the sales for the filtered region (e.g., "North").

  - The denominator uses `CALCULATE` with `REMOVEFILTERS(Sales[Region])` to remove the filter on the `Region` column, calculating the total sales across all regions.

  - The result is the percentage of the selected region's sales relative to total sales.

#### Output

If total sales are $100,000 and sales for "North" are $25,000, the measure returns `25,000 / 100,000 = 25%`.

### Key Points

- **REMOVEFILTERS** is a shorthand for `ALL` in many cases, but it is more explicit and easier to read when you want to remove filters from specific tables or columns.

- It only affects the filter context within the `CALCULATE` or `CALCULATETABLE` function it is used in.

- If no arguments are provided (e.g., `REMOVEFILTERS()`), it removes all filters from the current context, equivalent to `ALLSELECTED()` in some scenarios.

- Use with caution, as removing filters can lead to unexpected results if not aligned with the report's intended logic.

### Practical Example in a Report

Imagine a Power BI report with a slicer for `Year` and `Product`. You want a measure that calculates total sales ignoring the `Year` filter but respecting the `Product` filter:

```dax

Total Sales Ignoring Year =

CALCULATE(

    SUM(Sales[SalesAmount]),

    REMOVEFILTERS(Sales[Year])

)

```

This measure will sum `SalesAmount` for the selected product(s) across all years, even if a specific year is selected in the slicer.

### When to Use REMOVEFILTERS vs. ALL

- Use **REMOVEFILTERS** when you want to explicitly remove filters from specific tables/columns within a `CALCULATE` expression.

- Use **ALL** when you need to remove filters and return a table (e.g., for use in iterators like `SUMX` or `FILTER`).

- **REMOVEFILTERS** is generally preferred in modern DAX for clarity within `CALCULATE`.

### Limitations

- **REMOVEFILTERS** only works within `CALCULATE` or `CALCULATETABLE`. It cannot be used standalone.

- It does not remove row-level security (RLS) filters or other security-related constraints.

- It only affects the filter context, not the row context.

By using **REMOVEFILTERS**, you can create flexible and dynamic measures that adapt to user interactions in Power BI reports, making it a powerful tool for advanced calculations.