# Navigation

### First value

Returns the value of a variable for the first row in a given analytic window. –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#first_value)

```sql
FIRST_VALUE(@variable[ @ignore_null NULLS])
```

#### Return type

dynamic (input-dependent)

#### Parameters

| Name           | Type                                                                                                                       | Allowed values                                                                           | Required | Placeholder (in UI)        |
| -------------- | -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | -------- | -------------------------- |
| `@variable`    | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | true     | -                          |
| `@ignore_null` | [enum](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#enum)         | any of: `IGNORE`, `RESPECT`                                                              | false    | *(Ignore nulls (default))* |

### Lag

Returns the value of a variable on a preceding row within the analytic window –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#lag)

```sql
LAG(@variable, @literal[, @default_value])
```

#### Return type

dynamic (input-dependent)

#### Parameters

| Name             | Type                                                                                                                       | Allowed values                                                                           | Required | Placeholder (in UI) |
| ---------------- | -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | -------- | ------------------- |
| `@variable`      | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | true     | -                   |
| `@literal`       | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [integer](https://docs.redivis.com/reference/datasets/variables#integer)             | false    | *(1)*               |
| `@default_value` | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | false    | *(NULL)*            |

### Last value

Returns the value of a variable for the last row in a given analytic window. –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#last_value)

```sql
LAST_VALUE(@variable[ @ignore_null NULLS])
```

#### Return type

dynamic (input-dependent)

#### Parameters

| Name           | Type                                                                                                                       | Allowed values                                                                           | Required | Placeholder (in UI)        |
| -------------- | -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | -------- | -------------------------- |
| `@variable`    | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | true     | -                          |
| `@ignore_null` | [enum](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#enum)         | any of: `IGNORE`, `RESPECT`                                                              | false    | *(Ignore nulls (default))* |

### Lead

Returns the value of a variable on a subsequent row within the analytic window –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#lead)

```sql
LEAD(@variable, @literal[, @default_value])
```

#### Return type

dynamic (input-dependent)

#### Parameters

| Name             | Type                                                                                                                       | Allowed values                                                                           | Required | Placeholder (in UI) |
| ---------------- | -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | -------- | ------------------- |
| `@variable`      | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | true     | -                   |
| `@literal`       | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [integer](https://docs.redivis.com/reference/datasets/variables#integer)             | false    | *(1)*               |
| `@default_value` | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | false    | *(NULL)*            |

### Nth value

Returns the value at the Nth row of a given window frame. –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#nth_value)

```sql
NTH_VALUE(@variable, @literal[ @ignore_null NULLS])
```

#### Return type

dynamic (input-dependent)

#### Parameters

| Name           | Type                                                                                                                       | Allowed values                                                                           | Required | Placeholder (in UI)        |
| -------------- | -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | -------- | -------------------------- |
| `@variable`    | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [Redivis type](https://docs.redivis.com/reference/datasets/variables#variable-types) | true     | -                          |
| `@literal`     | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [integer](https://docs.redivis.com/reference/datasets/variables#integer)             | true     | -                          |
| `@ignore_null` | [enum](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#enum)         | any of: `IGNORE`, `RESPECT`                                                              | false    | *(Ignore nulls (default))* |

### Percentile (continuous)

Computes the specified percentile value for a variable within an ordered partition, with linear interpolation. –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#percentile_cont)

```sql
PERCENTILE_CONT(@variable, @literal[ @ignore_null NULLS])
```

#### Return type

float

#### Parameters

| Name           | Type                                                                                                                       | Allowed values                                                                                                                                     | Required | Placeholder (in UI)        |
| -------------- | -------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | -------- | -------------------------- |
| `@variable`    | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [integer](https://docs.redivis.com/reference/datasets/variables#integer), [float](https://docs.redivis.com/reference/datasets/variables#float) | true     | *(variable)*               |
| `@literal`     | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [float](https://docs.redivis.com/reference/datasets/variables#float)                                                                           | true     | *(Value between \[0, 1])*  |
| `@ignore_null` | [enum](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#enum)         | any of: `IGNORE`, `RESPECT`                                                                                                                        | false    | *(Ignore nulls (default))* |

### Percentile (discrete)

Computes the specified percentile value for a variable within an ordered partition. Returns the first sorted value with cumulative distribution greater than or equal to the percentile. –> [learn more](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#percentile_disc)

```sql
PERCENTILE_DISC(@variable, @literal[ @ignore_null NULLS])
```

#### Return type

float

#### Parameters

| Name           | Type                                                                                                                       | Allowed values                                                                                                                                     | Required | Placeholder (in UI)        |
| -------------- | -------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | -------- | -------------------------- |
| `@variable`    | [variable](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#variable) | any [integer](https://docs.redivis.com/reference/datasets/variables#integer), [float](https://docs.redivis.com/reference/datasets/variables#float) | true     | *(variable)*               |
| `@literal`     | [literal](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#literal)   | any [float](https://docs.redivis.com/reference/datasets/variables#float)                                                                           | true     | *(Value between \[0, 1])*  |
| `@ignore_null` | [enum](https://docs.redivis.com/reference/projects/transform-nodes/variable-creation-methods/common-elements#enum)         | any of: `IGNORE`, `RESPECT`                                                                                                                        | false    | *(Ignore nulls (default))* |