# Spatial Accessors

Components used to obtain properties about a geography data type or a set of geographies.

## ST Geometry Type

**Description**

This component adds a column containing the geography type of the geography in each row of the input table.

**Inputs**

* `Source table [Table]`
* `Geo column [Column]`

**Outputs**

* `Result table [Table]`

**External links**

[BigQuery reference](https://cloud.google.com/bigquery/docs/reference/standard-sql/geography_functions#st_geometrytype)

[PostgreSQL reference](https://postgis.net/docs/ST_GeometryType.html)

## ST NumGeometries

**Description**

This component creates a new table with an additional column with the number of parts in each input geography.

**Inputs**

* `Source table [Table]`
* `Geo column [Column]`

**Outputs**

* `Result table [Table]`

**External links**

[BigQuery reference](https://cloud.google.com/bigquery/docs/reference/standard-sql/geography_functions#st_numgeometries)

[Redshift reference](https://docs.aws.amazon.com/es_es/redshift/latest/dg/ST_NumGeometries-function.html)

[PostgreSQL reference](https://postgis.net/docs/ST_NumGeometries.html)

## ST NumPoints

**Description**

This component creates a new table with an additional column with the number of points in each input geography.

**Inputs**

* `Source table [Table]`
* `Geo column [Column]`

**Outputs**

* `Result table [Table]`

**External links**

[BigQuery reference](https://cloud.google.com/bigquery/docs/reference/standard-sql/geography_functions#st_numpoints)

[Snowflake reference](https://docs.snowflake.com/en/sql-reference/functions/st_npoints)

[Redshift reference](https://docs.aws.amazon.com/redshift/latest/dg/ST_NumPoints-function.html)

[PostgreSQL reference](https://postgis.net/docs/ST_NumPoints.html)

## ST Point N

**Description**

This component adds a new column with the point at the n-th position in the original input geography.

The geography must be of type linestring.

It will set the column value to null if the original geography is not a linestring, if it is empty, or if there is no vertex at the given index.

**Inputs**

* `Source table [Table]`
* `Geo column [Column]`
* `Point index [Number]`

**Outputs**

* `Result table [Table]`

**External links**

[BigQuery reference](https://cloud.google.com/bigquery/docs/reference/standard-sql/geography_functions#st_pointn)

[Snowflake reference](https://docs.snowflake.com/en/sql-reference/functions/st_pointn)

[Redshift reference](https://docs.aws.amazon.com/redshift/latest/dg/ST_PointN-function.html)

[PostgreSQL reference](https://postgis.net/docs/ST_PointN.html)

## ST X / ST Y <a href="#st-x-st-y" id="st-x-st-y"></a>

**Description**

This component creates a new table with additional columns containing X and Y coordinates of the geographies in the input table. This only applies to the case of point geographies.

**Inputs**

* `Source table [Table]`
* `Geo column [Column]`

**Outputs**

* `Result table [Table]`

**External links**

[BigQuery reference](https://cloud.google.com/bigquery/docs/reference/standard-sql/geography_functions#st_x)

[Snowflake reference](https://docs.snowflake.com/en/sql-reference/functions/st_x.html)

[Redshift reference](https://docs.aws.amazon.com/redshift/latest/dg/ST_X-function.html)

[PostgreSQL reference](https://postgis.net/docs/ST_X.html)


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