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

# Spatial Relationships

export const OcientGeo = "OcientGeo™";

{OcientGeo} spatial relationship functions use arguments to test for different types of spatial relationships.

## ST\_CLUSTERDBSCAN

Returns the cluster number for each input geography based on a two-dimensional implementation of the density-based spatial clustering of applications with noise ([DBSCAN](https://en.wikipedia.org/wiki/DBSCAN)) algorithm.

This function is a window function because the resulting value for an individual row depends on other rows and not just itself. No frame specification is allowed.

This function supports sort orders, but it is unnecessary unless deterministic resolution of tie-breaking in cluster determination is required. This tie-breaking happens only in situations where a point on the boundary of a cluster is equally valid for multiple clusters. In these cases, the result depends on the sort order of the data. For this reason, you might want to sort the data to force the deterministic behavior by using an `ORDER BY` in the `OVER` clause.

The function returns NULL for any row not included in a cluster.

**Syntax**

```sql SQL theme={null}
ST_CLUSTERDBSCAN(geo, eps, min_neighbors)
```

| **Argument**    | **Data** **Type**                   | **Description**                                                                                                                                  |
| --------------- | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| `geo`           | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be grouped into a cluster based on the DBSCAN algorithm.                                                                  |
| `eps`           | `DOUBLE`                            | A numeric argument that controls the separation between objects before they are considered a new cluster. <br />The `eps` argument is in meters. |
| `min_neighbors` | `BIGINT`                            | The minimum number of objects within the appropriate distance of each other that need to exist before it is considered a cluster.                |

**Example**

```sql SQL theme={null}
SELECT ST_CLUSTERDBSCAN(ST_POINT(1.5, 1.5), 1.0, 1) OVER();
```

*Output*: `1`

## ST\_CONTAINS

Returns `TRUE` if the first geographic argument, `geo1`, contains the second geographic argument, `geo2`.

`geo1` contains `geo2` only if all of these criteria are met:

* No `POINT` values of `geo2` are located at the exterior of `geo1`.
* At least one `POINT` in the interior of `geo2` lies in the interior of `geo1`.

Geographies do not contain their boundaries, therefore, all `POINT` values in a `LINESTRING` are interior, except for the endpoints, which are regarded as exterior boundaries.

If either `geo1` or `geo2` is NULL, then the function returns NULL.

**Syntax**

```sql SQL theme={null}
SELECT ST_CONTAINS(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                                                                 |
| ------------ | ----------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2`.<br />The `POINT` values in `geo1` are evaluated to determine if they are contained within `geo2`. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`.<br />The `POINT` values in `geo2` are evaluated to determine if they are contained within `geo1`. |

**Example**

```sql SQL theme={null}
SELECT ST_CONTAINS(
    ST_LINEFROMTEXT('LINESTRING(0 0, 1 1, 2 2)'),
    ST_POINT(1, 1));
```

*Output*: `true`

## ST\_CONTAINSPROPERLY

This function is similar to ST\_CONTAINS, but it has stricter criteria.

Returns true if `geo2` lies entirely in the interior of `geo1` and does not intersect or touch the boundary or exterior points.

Returns NULL if either `geo1` or `geo2` is NULL.

**Syntax**

```sql SQL theme={null}
ST_CONTAINSPROPERLY(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                                                                  |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2`. <br />The `POINT` values in `geo1` are evaluated to determine if they are contained within `geo2`. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`. <br />The `POINT` values in `geo2` are evaluated to determine if they are contained within `geo1`. |

**Examples**

In this example, the first geographic object is a `POLYGON` representing a simple square (0 0, 1 0, 1 1, 0 1). The second geographic object is a small `LINESTRING` that spans from the point (0.25 0.25) to the point (0.75 0.75).

Because the line is located entirely within the polygon, never touching its boundaries, the function evaluates to `true`.

```sql SQL theme={null}
SELECT ST_CONTAINSPROPERLY(
        ST_MAKEPOLYGON(
            ST_MAKELINE(
                ARRAY [ST_POINT(0, 0), ST_POINT(1, 0), ST_POINT(1, 1), ST_POINT(0, 1), ST_POINT(0, 0)])),
        ST_MAKELINE(ST_POINT(0.25, 0.25), ST_POINT(0.75, 0.75)));
```

*Output*: `TRUE`

The second geographic object is slightly altered in this example, where the line spans from (0 0) to (1 1). Both of these endpoints touch the boundaries of the polygon, so the function now evaluates to `false`.

```sql SQL theme={null}
SELECT ST_CONTAINSPROPERLY(
        ST_MAKEPOLYGON(
            ST_MAKELINE(
                ARRAY [ST_POINT(0, 0), ST_POINT(1, 0), ST_POINT(1, 1), ST_POINT(0, 1), ST_POINT(0, 0)])),
        ST_MAKELINE(ST_POINT(0, 0), ST_POINT(1, 1)));
```

*Output*: `FALSE`

## ST\_COVERS

Returns `TRUE` if no `POINT` in `geo2` is outside of `geo1`.

Returns NULL if either `geo1` or `geo2` is NULL.

**Syntax**

```sql SQL theme={null}
ST_COVERS(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                                                                  |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2`. <br />The `POINT` values in `geo2` are evaluated to determine if they are contained within `geo2`. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`. <br />The `POINT` values in `geo2` are evaluated to determine if they are contained within `geo1`. |

**Example**

```sql SQL theme={null}
SELECT ST_COVERS(
        ST_MAKEPOLYGON(
            ST_MAKELINE(
                ARRAY [ST_POINT(0, 0), ST_POINT(1, 0), ST_POINT(1, 1), ST_POINT(0, 1), ST_POINT(0, 0)])),
        ST_MAKELINE(ST_POINT(0, 0), ST_POINT(1, 1)));
```

*Output*: `TRUE`

## ST\_COVEREDBY

This function operates similarly to ST\_COVERS, except the arguments are interchanged.

Returns `TRUE` if no `POINT` in `geo1` is outside of `geo2`.

Returns NULL if either `geo1` or `geo2` is NULL.

**Syntax**

```sql SQL theme={null}
ST_COVEREDBY(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                                                                  |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2`. <br />The `POINT` values in `geo1` are evaluated to determine if they are contained within `geo2`. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1` <br />The `POINT` values in `geo1` are evaluated to determine if they are contained within `geo2`.  |

**Example**

```sql SQL theme={null}
SELECT ST_COVEREDBY(
    ST_POINT(1,1),
    ST_POLYGON('POLYGON((1 1, 2 1, 2 2, 1 1))'));
```

*Output*: `TRUE`

## ST\_CROSSES

Returns `TRUE` if two geospatial objects meet this criteria:

* The intersection of the geospatial interiors is not empty.
* The intersection is not equal to `geo1` or `geo2`.
* Neither geospatial object is a single `POINT`.

Returns NULL if either argument is NULL.

**Syntax**

```sql SQL theme={null}
ST_CROSSES(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                               |
| ------------ | ----------------------------------- | ----------------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2` to evaluate whether they cross.  |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`  to evaluate whether they cross. |

**Example**

```sql SQL theme={null}
SELECT ST_CROSSES(
    ST_LINESTRING(ST_POINT(0,0), ST_POINT(2,2)),
    ST_LINESTRING(ST_POINT(1,0), ST_POINT(1,5)));
```

*Output*:  `TRUE`

## ST\_DISJOINT

Returns `true` if the specified geographies have no intersection, including boundaries. Both geographic arguments can be different types.

This function is the opposite of the [ST\_INTERSECTS](#st_intersects) function.

**Syntax**

```sql SQL theme={null}
ST_DISJOINT(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                   |
| ------------ | ----------------------------------- | --------------------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2` to evaluate whether they intersect.  |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`  to evaluate whether they intersect. |

Example

```sql SQL theme={null}
SELECT ST_DISJOINT(
    ST_POLYGON(ST_LINESTRING('LINESTRING(2 3, 2 4, 2 4, 2 3)')),
    ST_POLYGON(ST_LINESTRING('LINESTRING(1 2, 1 4, 1 5, 1 2)')));
```

*Output*:  `TRUE`

## ST\_DWITHIN

Returns `TRUE` if the geographies are within a specified distance in meters.

**Syntax**

```sql SQL theme={null}
ST_DWITHIN(geo1, geo2, distance_meters)
```

| **Argument**      | **Data** **Type**                   | **Description**                                                                                                             |
| ----------------- | ----------------------------------- | --------------------------------------------------------------------------------------------------------------------------- |
| `geo1`            | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2` to evaluate whether they are within the specified distance `distance_meters`.  |
| `geo2`            | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`  to evaluate whether they are within the specified distance `distance_meters`. |
| `distance_meters` | `DOUBLE`                            | A numeric value that represents the number of meters to evaluate the distance between `geo1` and `geo2`.                    |

**Example**

```sql SQL theme={null}
SELECT ST_DWITHIN(
    ST_POINT('POINT(1 1)'),
    ST_POINT('POINT(0 0)'),
    100);
```

*Output*: `FALSE`

## ST\_EQUALS

Returns `TRUE` if both geographies are spatially equal.

**Syntax**

```sql SQL theme={null}
ST_EQUALS(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                   |
| ------------ | ----------------------------------- | --------------------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2` to evaluate whether they are equal.  |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`  to evaluate whether they are equal. |

Example

```sql SQL theme={null}
SELECT ST_EQUALS(
    ST_POLYGON(ST_LINESTRING('LINESTRING(10 10, 0 0, 0 0, 10 10)')),
    ST_POLYGON(ST_LINESTRING('LINESTRING(10 10, 0 0, 0 0, 10 10)')));
```

*Output*:  `True`

## ST\_INTERSECTS

Returns `TRUE` if the specified geographies intersect, including boundaries.

This function is the opposite of the [ST\_DISJOINT](#st_disjoint) function.

**Syntax**

```sql SQL theme={null}
ST_INTERSECTS(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                   |
| ------------ | ----------------------------------- | --------------------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2` to evaluate whether they intersect.  |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`  to evaluate whether they intersect. |

**Example**

```sql SQL theme={null}
SELECT ST_INTERSECTS(
    ST_POLYGON(ST_LINESTRING('LINESTRING(2 3, 2 4, 2 4, 2 3)')),
    ST_POLYGON(ST_LINESTRING('LINESTRING(1 2, 1 4, 1 5, 1 2)')));
```

*Output*:  `FALSE`

## ST\_ISCCW

Alias for [ST\_ISPOLYGONCCW](#st_ispolygonccw).

## ST\_ISCLOSED

Returns `TRUE` if an input `LINESTRING` has starting and ending points that are equal.

If you specify a `POLYGON` or `POINT` value, the function returns `true` if the specified geography is not empty.

**Syntax**

```sql SQL theme={null}
ST_ISCLOSED(line)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                                                                                                                                                                        |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `line`       | `POINT`, `LINESTRING`, or `POLYGON` | If you specify a `LINESTRING` object, the function evaluates it to determine whether its starting and ending points are equal. <br />If you specify a `POLYGON` or `POINT` value, the function returns `true` if the specified geography is not empty. |

**Example**

```sql SQL theme={null}
SELECT ST_ISCLOSED(
    ST_LINESTRING('LINESTRING(1 2, 1 3, 1 2)'));
```

*Output*:  `TRUE`

## ST\_ISPOLYGONCW

Alias for `BOOLNOT(ST_ISCCW(poly))`.

Returns `TRUE` if an input `POLYGON` has an exterior that is clockwise.

If the `POLYGON` argument is empty, this function returns `TRUE`. If the argument is NULL, this function returns NULL.

**Syntax**

```sql SQL theme={null}
ST_ISPOLYGONCW(poly)
```

| **Argument** | **Data** **Type** | **Description**                                                                                      |
| ------------ | ----------------- | ---------------------------------------------------------------------------------------------------- |
| `poly`       | `POLYGON`         | A `POLYGON` object to evaluate to determine whether its point values align in a clockwise direction. |

**Example**

```sql SQL theme={null}
SELECT ST_ISPOLYGONCW(
    ST_POLYGON('POLYGON((0 0,1 0,1 1,0 1,0 0))'));
```

*Output*:  `FALSE`

## ST\_ISPOLYGONCCW

Alias for ST\_ISCCW.

Returns `TRUE` if an input `POLYGON` has an exterior that is counter-clockwise.

If the `POLYGON` argument is empty, this function returns `TRUE`. If the argument is NULL, this function returns NULL.

**Syntax**

```sql SQL theme={null}
ST_ISPOLYGONCCW(poly)
```

| **Argument** | **Data** **Type** | **Description**                                                                                              |
| ------------ | ----------------- | ------------------------------------------------------------------------------------------------------------ |
| `poly`       | `POLYGON`         | A `POLYGON` object to evaluate to determine whether its point values align in a counter-clockwise direction. |

**Example**

```sql SQL theme={null}
SELECT ST_ISPOLYGONCCW(
    ST_POLYGON('POLYGON((0 0,1 0,1 1,0 1,0 0))'));
```

*Output*: `TRUE`

## ST\_ISRING

Returns `TRUE` if the specified `LINESTRING` is closed and does not intersect itself. This function is equivalent to evaluating both [ST\_ISCLOSED](#st_isclosed) and [ST\_ISSIMPLE](#st_issimple).

If you specify a value other than `LINESTRING`, the function throws an error.

**Syntax**

```sql SQL theme={null}
ST_ISRING(geo)
```

| **Argument** | **Data** **Type** | **Description**                                                                                                                      |
| ------------ | ----------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| `line`       | `LINESTRING`      | A `LINESTRING` object to evaluate to determine whether its starting and ending points are equal and whether it has no intersections. |

**Example**

```sql SQL theme={null}
SELECT ST_ISRING(
    ST_LINESTRING('LINESTRING(1 2, 2 4, 1 3, 1 2)'));
```

*Output*:  `TRUE`

## ST\_ISSIMPLE

For `LINESTRING` values, this function returns `FALSE` if any line segments intersect anywhere besides the endpoints.

For `POLYGON` values, the function returns `FALSE` if either the exterior ring or any interior hole is not simple.

For `POINT` values, the function always returns `TRUE`.

**Syntax**

```sql SQL theme={null}
ST_ISSIMPLE(geo)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                                                                                                                                                                                                                                                                                                          |
| ------------ | ----------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `geo`        | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to evaluate to determine if any points intersect. <br />For `LINESTRING` values, this function returns `FALSE` if any line segments intersect anywhere besides the endpoints. <br />For `POLYGON` values, the function returns `FALSE` if either the exterior ring or any interior hole is not simple. <br />For `POINT` values, the function always returns `TRUE`. |

**Example**

```sql SQL theme={null}
SELECT ST_ISSIMPLE(
    ST_POLYGON('POLYGON((1 2, 3 4, 3 5, 1 2))'));
```

*Output*: `TRUE`

## ST\_ISVALID

Returns `TRUE` if the specified geospatial value is a well-formed and valid geography according to the [OGC standards](https://www.ogc.org/standard/sfa/).

`LINESTRING` values are not valid if they are composed of more than one `POINT` with the same coordinates.

`POLYGON` values are valid if they are composed of one external ring (shell) and zero or more internal rings. A ring is a `LINESTRING` where only the first and last `POINT` intersect each other. All internal rings need to be contained inside the shell, and none of the rings should intersect with each other in more than one `POINT`.

**Syntax**

```sql SQL theme={null}
ST_ISVALID(geo1)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------ |
| `geo`        | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to evaluate to determine if it is a well-formed geography. |

**Example**

```sql SQL theme={null}
SELECT ST_ISVALID(
    ST_LINESTRING('LINESTRING(1 2, 2 4)'));
```

*Output*: `TRUE`

## ST\_OVERLAPS

Returns `TRUE` if both geographic arguments are of the same dimension and intersect, but neither contains the other. Returns NULL if either `geo1` or `geo2` is NULL.

**Syntax**

```sql SQL theme={null}
ST_OVERLAPS(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                  |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------ |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object for evaluation to determine if it is shaped similarly and intersects `geo2`. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object for evaluation to determine if it is shaped similarly and intersects `geo1`. |

**Example**

```sql SQL theme={null}
SELECT ST_OVERLAPS(
    ST_LINESTRING(ST_POINT(0,0), ST_POINT(2,2)),
    ST_LINESTRING(ST_POINT(1,1), ST_POINT(3,3)));
```

*Output*:  `TRUE`

## ST\_POINTINSIDECIRCLE

Returns `TRUE` if the geographic object is inside a circle centered at the specified point coordinates and with the specified radius.

**Syntax**

```sql SQL theme={null}
ST_POINTINSIDECIRCLE(geo, center_x, center_y, circle_radius)
```

| **Argument**    | **Data** **Type**                   | **Description**                                                                                                 |
| --------------- | ----------------------------------- | --------------------------------------------------------------------------------------------------------------- |
| `geo`           | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object for evaluation to determine if it is contained within a circle of the specified dimensions. |
| `center_x`      | `DOUBLE`                            | The x coordinate of the center of the circle to evaluate.                                                       |
| `center_y`      | `DOUBLE`                            | The y coordinate of the center of the circle to evaluate.                                                       |
| `circle_radius` | `DOUBLE`                            | The radius in meters of the circle to evaluate.                                                                 |

**Example**

```sql SQL theme={null}
SELECT ST_POINTINSIDECIRCLE(
    ST_POINT(1, 3), 1, 2, 3000000);
```

*Output*: `TRUE`

## ST\_RELATE

Returns the [DE-9IM](https://postgis.net/workshops/postgis-intro/de9im.html) intersection string that represents the nature of the intersection with the specified geographies. If you specify an intersection pattern as the third argument, this function returns `TRUE` if the intersection of the geographies satisfies the pattern and `FALSE` otherwise.

**Syntax**

```sql SQL theme={null}
ST_RELATE(geo1, geo2, [, intersectionPattern])
```

| **Parameter**         | **Data Type**                       | **Description**                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| --------------------- | ----------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `geo1`                | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to relate with `geo2`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| `geo2`                | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to relate with `geo1`.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| `intersectionPattern` | `STRING`                            | Optional.<br />Intersection pattern to query the nature of the intersection of `geo1` and `geo2`.<br />Must contain exactly 9 characters, corresponding to the component (interior, boundary, or exterior) intersections considered by DE-9IM. Supported characters are:<br />\* `T` —  Components intersect.<br />\* `F` —  Components do not intersect.<br />\* `0` — Component intersection is zero-dimensional.<br />\* `1` — Component intersection is 1-dimensional.<br />\* `2` — Component intersection is 2-dimensional.<br />\* `*` — Specify no restriction on the component intersection. |

**Examples**

Determine the nature of the intersection between the point `(0.0, 0.0)` and the line from `-1 0` to `1 0`. This function returns the DE-9IM string `0FFFFF102`, which means that the boundaries do not intersect at all, but there is evidence of an intersection at the zero, one, and two-dimensional spaces.

```sql SQL theme={null}
SELECT ST_RELATE(ST_POINT(0.0, 0.0),
    ST_LINESTRING('LINESTRING(-1 0, 1 0)'));
```

\*Output: \*`0FFFFF102`

Determine whether the intersection between the point `(0.0, 0.0)` and the line from `-1 0` to `1 0` follows the DE-9IM pattern string `TF*FFF102`. This function returns `TRUE`, which means the nature of the intersection between these two geographies conforms to this pattern.

```sql SQL theme={null}
SELECT ST_RELATE(ST_POINT(0.0, 0.0),
    ST_LINESTRING('LINESTRING(-1 0, 1 0)'), 'TF*FFF102');
```

\*Output: \*`TRUE`

## ST\_TOUCHES

Returns `TRUE` if the only `POINT` values in common between the two geographic arguments lie in the union of their boundaries.

**Syntax**

```sql SQL theme={null}
ST_TOUCHES(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                       |
| ------------ | ----------------------------------- | --------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object for evaluation to determine if it touches `geo2`. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object for evaluation to determine if it touches `geo1`. |

**Example**

```sql SQL theme={null}
SELECT ST_TOUCHES(
    ST_LINESTRING('LINESTRING(1.0 3.0, 0.0 3.0)'),
    ST_LINESTRING('LINESTRING(1.0 3.0, 2.0 3.0)'));
```

*Output*: `TRUE`

## ST\_WITHIN

Returns `TRUE` if the geography specified by the first argument is fully inside the geography specified by the second argument.

`ST_WITHIN(geo1, geo2)` is equivalent to `ST_CONTAINS(geo2, geo1)`. For details, see [ST\_CONTAINS](#st_contains).

**Syntax**

```sql SQL theme={null}
ST_WITHIN(geo1, geo2)
```

| **Argument** | **Data** **Type**                   | **Description**                                                                                            |
| ------------ | ----------------------------------- | ---------------------------------------------------------------------------------------------------------- |
| `geo1`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo2` to evaluate whether it is fully inside this second geography. |
| `geo2`       | `POINT`, `LINESTRING`, or `POLYGON` | A geospatial object to be compared to `geo1`  to evaluate whether it contains the first geography.         |

**Example**

```sql SQL theme={null}
SELECT ST_WITHIN(
    ST_POINT(1, 1),
    ST_LINEFROMTEXT('LINESTRING(0 0, 1 1, 2 2)')
);
```

*Output*: `true`

## Related Links

[Geospatial Data Types](/data-types#geospatial-data-types)

[Spatial Measurement](/spatial-measurement)

[Spatial Operators](/spatial-operators)