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

# ST_Union

export const InternalLink = ({version, path = "", children, ...props}) => {
  let detectedVersion = version || "stable";
  if (typeof window !== 'undefined' && !version) {
    const match = window.location.pathname.match(/\/docs\/([^/]+)/);
    if (match) {
      detectedVersion = match[1];
    }
  }
  const normalizedPath = path.startsWith("/") ? path.slice(1) : path;
  return <a href={`/docs/${detectedVersion}/${normalizedPath}`} {...props}>
      {children}
    </a>;
};

Given a set of shapes (e.g., from a <InternalLink path="selection-queries">selection query</InternalLink>), `ST_Union` combines that set of shapes into a single shape. The resulting shape can then be passed to functions that operate on a single shape, such as <InternalLink path="st_convexhull">`ST_ConvexHull`</InternalLink>.

`ST_Union` works on the following data types:

* <InternalLink path="architecture/glossary#geometry">`GEOMETRY`</InternalLink>

<Note>
  The non-aggregate version of `ST_Union` is not yet implemented.
</Note>

<Note>
  Unlike `ST_Collect`, which does not change the shapes it operates on and merely gathers them into a collection,
  `ST_Union` modifies the shapes it operates on, merging them together.
</Note>

## Examples

In this example, we will generate a single geometry from many individual points using `ST_Union`.

1. Create a temporary table to hold all the points, which will be in <InternalLink path="architecture/glossary#wkt">Well Known Text (WKT)</InternalLink> format:

   ```sql theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   CREATE TABLE tmp (ID UUID DEFAULT gen_random_uuid(), geom_text STRING);
   ```

2. Insert the points with the following statement:

   ```sql theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   INSERT INTO tmp (geom_text) VALUES
   ('POINT (-73.962090000000003 40.609226)'),
   ('POINT (-74.007309000000006 40.619892)'),
   ('POINT (-73.949724000000003 41.498103999999998)'),
   ('POINT (-72.390808000000007 40.961891999999999)'),
   ('POINT (-77.937476000000004 43.218451000000002)'),
   ('POINT (-73.842978000000002 40.944997999999998)'),
   ('POINT (-73.928291999999999 40.680906999999998)'),
   ('POINT (-73.914484999999999 40.775554)'),
   ('POINT (-73.993281999999994 40.722833000000001)'),
   ('POINT (-73.900373999999999 41.691662000000001)'),
   ('POINT (-73.787897999999998 42.250467)'),
   ('POINT (-75.062138000000004 42.454003)'),
   ('POINT (-73.992576 40.753692000000001)'),
   ('POINT (-75.647559999999999 44.590586000000002)'),
   ('POINT (-73.698974000000007 40.832500000000003)'),
   ('POINT (-73.957140999999993 40.728864000000002)'),
   ('POINT (-73.954773000000003 40.732667999999997)'),
   ('POINT (-74.024456000000001 41.521116999999997)'),
   ('POINT (-73.785302000000001 43.081800000000001)'),
   ('POINT (-74.860436000000007 43.040708000000002)'),
   ('POINT (-74.001165999999998 40.687367000000002)'),
   ('POINT (-78.809790000000007 42.845362000000002)'),
   ('POINT (-75.061370999999994 41.608192000000003)'),
   ('POINT (-76.499137000000005 42.440623000000002)'),
   ('POINT (-73.379208000000006 43.027712000000001)'),
   ('POINT (-73.684466999999998 41.259498000000001)'),
   ('POINT (-74.003300999999993 40.706865999999998)'),
   ('POINT (-76.384369000000007 43.034204000000003)'),
   ('POINT (-73.983408999999995 40.723255000000002)'),
   ('POINT (-74.670794000000001 42.371471999999997)'),
   ('POINT (-73.963970000000003 40.804766999999998)'),
   ('POINT (-73.989228999999995 40.743865)'),
   ('POINT (-73.487143000000003 42.587166000000003)'),
   ('POINT (-78.608046999999999 42.767758999999998)'),
   ('POINT (-78.824476000000004 42.754263999999999)'),
   ('POINT (-72.185676999999998 40.963121999999998)'),
   ('POINT (-78.639556999999996 43.001435000000001)'),
   ('POINT (-77.428916999999998 43.212463)'),
   ('POINT (-73.964771999999996 40.770071999999999)'),
   ('POINT (-73.937073999999996 40.578499000000001)'),
   ('POINT (-74.076237000000006 40.636749000000002)'),
   ('POINT (-73.923480999999995 41.091296)'),
   ('POINT (-78.00206 42.718395000000001)'),
   ('POINT (-74.992647000000005 43.018610000000002)'),
   ('POINT (-73.991900000000001 40.683962000000001)'),
   ('POINT (-74.119761999999994 42.040447)'),
   ('POINT (-73.955706000000006 40.785203000000003)'),
   ('POINT (-73.698363000000001 42.709778)'),
   ('POINT (-75.296575000000004 43.098322000000003)'),
   ('POINT (-73.804747000000006 42.709560000000003)'),
   ('POINT (-79.326158000000007 42.102457000000001)'),
   ('POINT (-73.938518000000002 40.837735000000002)'),
   ('POINT (-73.976410999999999 40.672561999999999)'),
   ('POINT (-73.978993000000003 40.745123999999997)'),
   ('POINT (-77.587306999999996 43.159300999999999)'),
   ('POINT (-74.001251999999994 40.734977000000001)'),
   ('POINT (-76.206723999999994 43.102012000000002)'),
   ('POINT (-78.876722000000001 42.922820999999999)'),
   ('POINT (-73.495369999999994 44.703318000000003)'),
   ('POINT (-79.052965999999998 43.105055)'),
   ('POINT (-73.551120999999995 41.189729)'),
   ('POINT (-73.760520999999997 40.809649999999998)'),
   ('POINT (-73.952360999999996 42.077744000000003)'),
   ('POINT (-76.511525000000006 43.456606000000001)'),
   ('POINT (-75.036815000000004 42.448793000000002)'),
   ('POINT (-75.544407000000007 42.826815000000003)'),
   ('POINT (-73.686974000000006 40.724902)'),
   ('POINT (-77.582922999999994 43.154963000000002)'),
   ('POINT (-78.836257000000003 42.960456999999998)'),
   ('POINT (-73.919056999999995 41.091124999999998)'),
   ('POINT (-73.998487999999995 40.733795999999998)'),
   ('POINT (-73.939606999999995 40.815913000000002)'),
   ('POINT (-74.058107000000007 41.083153000000003)'),
   ('POINT (-73.991060000000004 40.733919)'),
   ('POINT (-73.967905000000002 40.758032999999998)'),
   ('POINT (-73.875281000000001 41.016382999999998)'),
   ('POINT (-77.134634000000005 42.961303000000001)'),
   ('POINT (-78.885418999999999 42.906629000000002)'),
   ('POINT (-73.553145999999998 40.665826000000003)'),
   ('POINT (-73.834867000000003 42.621578999999997)'),
   ('POINT (-73.982307000000006 40.752575)'),
   ('POINT (-77.816855000000004 42.795613000000003)'),
   ('POINT (-73.962288000000001 40.671320999999999)'),
   ('POINT (-72.354918999999995 41.083874999999999)'),
   ('POINT (-73.965331000000006 40.806128999999999)'),
   ('POINT (-74.080895999999996 41.844256000000001)'),
   ('POINT (-73.942249000000004 40.812187000000002)'),
   ('POINT (-73.974255999999997 40.783757999999999)'),
   ('POINT (-73.990206999999998 40.754969000000003)'),
   ('POINT (-73.601747000000003 41.562685000000002)'),
   ('POINT (-74.117880999999997 42.040733000000003)'),
   ('POINT (-73.979851999999994 40.664327999999998)'),
   ('POINT (-73.960042999999999 40.657589000000002)'),
   ('POINT (-74.009314000000003 40.715324000000003)'),
   ('POINT (-73.903509 40.703226000000001)'),
   ('POINT (-74.030330000000006 40.624713999999997)'),
   ('POINT (-73.909406000000004 40.814979000000001)'),
   ('POINT (-73.903160999999997 40.744929999999997)'),
   ('POINT (-73.504622999999995 41.952860000000001)'),
   ('POINT (-73.865554000000003 42.219304000000001)'),
   ('POINT (-73.981960000000001 40.766441)'),
   ('POINT (-73.913732999999993 40.698230000000002)'),
   ('POINT (-73.596703000000005 40.874966000000001)'),
   ('POINT (-73.974082999999993 40.686098000000001)'),
   ('POINT (-73.996341999999999 40.725087000000002)'),
   ('POINT (-73.595579999999998 42.363210000000002)'),
   ('POINT (-73.952259999999995 40.674118999999997)'),
   ('POINT (-73.993341000000001 40.730010999999998)'),
   ('POINT (-73.989086999999998 40.721902)'),
   ('POINT (-73.955855999999997 40.655028000000001)'),
   ('POINT (-74.002930000000006 40.731848999999997)'),
   ('POINT (-76.086753000000002 44.242874)'),
   ('POINT (-73.839067 42.681877999999998)'),
   ('POINT (-74.020105000000001 41.935105)'),
   ('POINT (-73.980250999999996 44.279376999999997)'),
   ('POINT (-74.085936000000004 41.747742000000002)'),
   ('POINT (-77.227361999999999 43.063468)'),
   ('POINT (-74.093547000000001 40.924697999999999)'),
   ('POINT (-74.986999999999995 44.669899999999998)'),
   ('POINT (-73.793597000000005 41.135866)'),
   ('POINT (-78.889482000000001 42.924545000000002)'),
   ('POINT (-73.914946 41.936036999999999)'),
   ('POINT (-73.9071 41.721612999999998)'),
   ('POINT (-73.993579999999994 40.736569000000003)'),
   ('POINT (-73.900388000000007 41.691189000000001)'),
   ('POINT (-73.989261999999997 40.663339000000001)'),
   ('POINT (-73.918380999999997 41.090746000000003)'),
   ('POINT (-73.862252999999995 40.839613)'),
   ('POINT (-73.806933000000001 40.989787999999997)'),
   ('POINT (-73.635006000000004 40.744909)'),
   ('POINT (-73.794276999999994 41.008797000000001)'),
   ('POINT (-73.759060000000005 41.022123000000001)'),
   ('POINT (-73.711965000000006 40.968676000000002)'),
   ('POINT (-74.668248000000006 42.372920000000001)'),
   ('POINT (-73.992476999999994 40.739109999999997)'),
   ('POINT (-74.131673000000006 44.326892000000001)'),
   ('POINT (-73.974738000000002 40.732664)'),
   ('POINT (-73.812349999999995 40.798867000000001)'),
   ('POINT (-78.641949999999994 42.991985)'),
   ('POINT (-73.962226999999999 40.778944000000003)'),
   ('POINT (-74.374174999999994 43.006495000000001)'),
   ('POINT (-77.095714000000001 43.041158000000003)'),
   ('POINT (-73.425764000000001 40.871898000000002)'),
   ('POINT (-73.466729000000001 44.708036)'),
   ('POINT (-73.978020999999998 40.686546999999997)'),
   ('POINT (-73.974082999999993 40.686098000000001)'),
   ('POINT (-73.971849000000006 40.602485000000001)'),
   ('POINT (-73.983153999999999 40.690553000000001)'),
   ('POINT (-77.052417000000005 42.143089000000003)'),
   ('POINT (-73.776431000000002 40.934483)'),
   ('POINT (-74.002019000000004 40.730927999999999)'),
   ('POINT (-73.772469999999998 42.264814000000001)'),
   ('POINT (-73.772876999999994 41.158641000000003)'),
   ('POINT (-72.296062000000006 41.002409)'),
   ('POINT (-74.021124999999998 41.933720000000001)'),
   ('POINT (-74.058107000000007 41.083153000000003)'),
   ('POINT (-73.967922999999999 40.801301000000002)'),
   ('POINT (-72.294278000000006 41.000610999999999)'),
   ('POINT (-76.499340000000004 42.438741999999998)'),
   ('POINT (-73.976597999999996 40.786610000000003)'),
   ('POINT (-73.988552999999996 40.703600000000002)'),
   ('POINT (-74.004855000000006 40.741959000000001)'),
   ('POINT (-73.844444999999993 40.925654999999999)'),
   ('POINT (-74.005101999999994 40.746654999999997)'),
   ('POINT (-73.937281999999996 42.819218999999997)'),
   ('POINT (-74.001677000000001 40.736243000000002)'),
   ('POINT (-73.684112999999996 40.981757000000002)'),
   ('POINT (-73.919064000000006 40.832836999999998)'),
   ('POINT (-78.885268999999994 42.944516)'),
   ('POINT (-72.299519000000004 40.994070999999998)'),
   ('POINT (-73.833477999999999 40.940247999999997)'),
   ('POINT (-73.695717000000002 41.783996999999999)'),
   ('POINT (-73.926891999999995 40.807422000000003)'),
   ('POINT (-74.085899999999995 41.747892999999998)'),
   ('POINT (-73.957583 41.417974999999998)');
   ```

3. Run the query below, which gathers the points into a single geometry using `ST_Union`, and converts the geometry to <InternalLink path="architecture/glossary#geojson">GeoJSON</InternalLink> so that we can view it with [geojson.io](http://geojson.io/):

   ```sql theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   WITH
       the_geoms_table
           AS (
               SELECT
                   st_union(st_geomfromtext(geom_text)) AS the_union
               FROM
                   tmp
           )
   SELECT
       st_asgeojson(the_union)
   FROM
       the_geoms_table;
   ```

   ```json theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   {
     "type": "MultiPoint",
     "coordinates": [
       [-79.326158, 42.102457],
       [-79.052966, 43.105055],
       [-78.889482, 42.924545],
       [-78.885419, 42.906629],
       [-78.885269, 42.944516],
       [-78.876722, 42.922821],
       [-78.836257, 42.960457],
       [-78.824476, 42.754264],
       [-78.80979, 42.845362],
       [-78.64195, 42.991985],
       [-78.639557, 43.001435],
       [-78.608047, 42.767759],
       [-78.00206, 42.718395],
       [-77.937476, 43.218451],
       [-77.816855, 42.795613],
       [-77.587307, 43.159301],
       [-77.582923, 43.154963],
       [-77.428917, 43.212463],
       [-77.227362, 43.063468],
       [-77.134634, 42.961303],
       [-77.095714, 43.041158],
       [-77.052417, 42.143089],
       [-76.511525, 43.456606],
       [-76.49934, 42.438742],
       [-76.499137, 42.440623],
       [-76.384369, 43.034204],
       [-76.206724, 43.102012],
       [-76.086753, 44.242874],
       [-75.64756, 44.590586],
       [-75.544407, 42.826815],
       [-75.296575, 43.098322],
       [-75.062138, 42.454003],
       [-75.061371, 41.608192],
       [-75.036815, 42.448793],
       [-74.992647, 43.01861],
       [-74.987, 44.6699],
       [-74.860436, 43.040708],
       [-74.670794, 42.371472],
       [-74.668248, 42.37292],
       [-74.374175, 43.006495],
       [-74.131673, 44.326892],
       [-74.119762, 42.040447],
       [-74.117881, 42.040733],
       [-74.093547, 40.924698],
       [-74.085936, 41.747742],
       [-74.0859, 41.747893],
       [-74.080896, 41.844256],
       [-74.076237, 40.636749],
       [-74.058107, 41.083153],
       [-74.03033, 40.624714],
       [-74.024456, 41.521117],
       [-74.021125, 41.93372],
       [-74.020105, 41.935105],
       [-74.009314, 40.715324],
       [-74.007309, 40.619892],
       [-74.005102, 40.746655],
       [-74.004855, 40.741959],
       [-74.003301, 40.706866],
       [-74.00293, 40.731849],
       [-74.002019, 40.730928],
       [-74.001677, 40.736243],
       [-74.001252, 40.734977],
       [-74.001166, 40.687367],
       [-73.998488, 40.733796],
       [-73.996342, 40.725087],
       [-73.99358, 40.736569],
       [-73.993341, 40.730011],
       [-73.993282, 40.722833],
       [-73.992576, 40.753692],
       [-73.992477, 40.73911],
       [-73.9919, 40.683962],
       [-73.99106, 40.733919],
       [-73.990207, 40.754969],
       [-73.989262, 40.663339],
       [-73.989229, 40.743865],
       [-73.989087, 40.721902],
       [-73.988553, 40.7036],
       [-73.983409, 40.723255],
       [-73.983154, 40.690553],
       [-73.982307, 40.752575],
       [-73.98196, 40.766441],
       [-73.980251, 44.279377],
       [-73.979852, 40.664328],
       [-73.978993, 40.745124],
       [-73.978021, 40.686547],
       [-73.976598, 40.78661],
       [-73.976411, 40.672562],
       [-73.974738, 40.732664],
       [-73.974256, 40.783758],
       [-73.974083, 40.686098],
       [-73.971849, 40.602485],
       [-73.967923, 40.801301],
       [-73.967905, 40.758033],
       [-73.965331, 40.806129],
       [-73.964772, 40.770072],
       [-73.96397, 40.804767],
       [-73.962288, 40.671321],
       [-73.962227, 40.778944],
       [-73.96209, 40.609226],
       [-73.960043, 40.657589],
       [-73.957583, 41.417975],
       [-73.957141, 40.728864],
       [-73.955856, 40.655028],
       [-73.955706, 40.785203],
       [-73.954773, 40.732668],
       [-73.952361, 42.077744],
       [-73.95226, 40.674119],
       [-73.949724, 41.498104],
       [-73.942249, 40.812187],
       [-73.939607, 40.815913],
       [-73.938518, 40.837735],
       [-73.937282, 42.819219],
       [-73.937074, 40.578499],
       [-73.928292, 40.680907],
       [-73.926892, 40.807422],
       [-73.923481, 41.091296],
       [-73.919064, 40.832837],
       [-73.919057, 41.091125],
       [-73.918381, 41.090746],
       [-73.914946, 41.936037],
       [-73.914485, 40.775554],
       [-73.913733, 40.69823],
       [-73.909406, 40.814979],
       [-73.9071, 41.721613],
       [-73.903509, 40.703226],
       [-73.903161, 40.74493],
       [-73.900388, 41.691189],
       [-73.900374, 41.691662],
       [-73.875281, 41.016383],
       [-73.865554, 42.219304],
       [-73.862253, 40.839613],
       [-73.844445, 40.925655],
       [-73.842978, 40.944998],
       [-73.839067, 42.681878],
       [-73.834867, 42.621579],
       [-73.833478, 40.940248],
       [-73.81235, 40.798867],
       [-73.806933, 40.989788],
       [-73.804747, 42.70956],
       [-73.794277, 41.008797],
       [-73.793597, 41.135866],
       [-73.787898, 42.250467],
       [-73.785302, 43.0818],
       [-73.776431, 40.934483],
       [-73.772877, 41.158641],
       [-73.77247, 42.264814],
       [-73.760521, 40.80965],
       [-73.75906, 41.022123],
       [-73.711965, 40.968676],
       [-73.698974, 40.8325],
       [-73.698363, 42.709778],
       [-73.695717, 41.783997],
       [-73.686974, 40.724902],
       [-73.684467, 41.259498],
       [-73.684113, 40.981757],
       [-73.635006, 40.744909],
       [-73.601747, 41.562685],
       [-73.596703, 40.874966],
       [-73.59558, 42.36321],
       [-73.553146, 40.665826],
       [-73.551121, 41.189729],
       [-73.504623, 41.95286],
       [-73.49537, 44.703318],
       [-73.487143, 42.587166],
       [-73.466729, 44.708036],
       [-73.425764, 40.871898],
       [-73.379208, 43.027712],
       [-72.390808, 40.961892],
       [-72.354919, 41.083875],
       [-72.299519, 40.994071],
       [-72.296062, 41.002409],
       [-72.294278, 41.000611],
       [-72.185677, 40.963122]
     ]
   }
   ```

4. Paste the JSON emitted in the previous step into [geojson.io](http://geojson.io/) and you should see an image like the following, which shows the location of [most of the independent bookstores in New York State](https://www.bookweb.org/member_directory/search/ABAmember/results/0/0/ny/0):

   <img src="https://mintcdn.com/cockroachlabs/LiqnOtencKgegCU0/images/v25.2/geospatial/st_union.png?fit=max&auto=format&n=LiqnOtencKgegCU0&q=85&s=d894fe8b08c5e3c559abf79b519b937f" alt="ST_Union example" width="1337" height="1137" data-path="images/v25.2/geospatial/st_union.png" />

5. Finally, drop the temporary table if you no longer need it:

   ```sql theme={"theme":{"light":"catppuccin-mocha","dark":"catppuccin-mocha"}}
   DROP TABLE tmp;
   ```

## See also

* <InternalLink path="export-spatial-data">Export Spatial Data</InternalLink>
* <InternalLink path="spatial-tutorial">Spatial tutorial</InternalLink>
* <InternalLink path="architecture/glossary">Spatial and GIS Glossary of Terms</InternalLink>
* <InternalLink path="spatial-indexes">Spatial indexes</InternalLink>
* <InternalLink path="functions-and-operators#spatial-functions">Spatial functions</InternalLink>
* <InternalLink path="st_covers">`ST_Covers`</InternalLink>
* <InternalLink path="st_coveredby">`ST_CoveredBy`</InternalLink>
* <InternalLink path="st_contains">`ST_Contains`</InternalLink>
* <InternalLink path="st_within">`ST_Within`</InternalLink>
* <InternalLink path="st_intersects">`ST_Intersects`</InternalLink>
* <InternalLink path="st_coveredby">`ST_CoveredBy`</InternalLink>
* <InternalLink path="st_covers">`ST_Covers`</InternalLink>
* <InternalLink path="st_disjoint">`ST_Disjoint`</InternalLink>
* <InternalLink path="st_equals">`ST_Equals`</InternalLink>
* <InternalLink path="st_overlaps">`ST_Overlaps`</InternalLink>
* <InternalLink path="st_touches">`ST_Touches`</InternalLink>
* <InternalLink path="st_convexhull">`ST_ConvexHull`</InternalLink>
* <InternalLink path="migrate-from-shapefiles">Migrate from Shapefiles</InternalLink>
* <InternalLink path="migrate-from-geojson">Migrate from GeoJSON</InternalLink>
* <InternalLink path="migrate-from-geopackage">Migrate from GeoPackage</InternalLink>
* <InternalLink path="migrate-from-openstreetmap">Migrate from OpenStreetMap</InternalLink>
* [Introducing Distributed Spatial Data in CockroachDB](https://www.cockroachlabs.com/blog/spatial-data) (blog post)
* <InternalLink path="geoserver">Using GeoServer with CockroachDB</InternalLink>