# Distinct count

> Supported in: Batch, Faster, Streaming

Calculate distinct number of values in column.

**Expression categories:** Aggregate

## Declared arguments

* **Expression:** The column of on which distinct count is computed.<br>*Expression\<ComparableType>*

**Output type:** *Long*

## Examples

### Example 1: Base case

**Argument values:**

* **Expression:** `values`

**Given input table:**

| values |
| ----- |
| 2 |
| 4 |
| 3 |

**Outputs:** 3

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### Example 2: Null case

**Argument values:**

* **Expression:** `values`

**Given input table:**

| values |
| ----- |
| 2 |
| 2 |
| *null* |

**Outputs:** 1

***