# Geometry Constructors

ST_BdPolyFromText Construct a Polygon given an arbitrary collection of closed linestrings as a MultiLineString Well-Known text representation.
geometry `ST_BdPolyFromText` text WKT integer srid

### Description

Construct a Polygon given an arbitrary collection of closed linestrings as a MultiLineString Well-Known text representation.

Throws an error if WKT is not a MULTILINESTRING. Throws an error if output is a MULTIPOLYGON; use ST_BdMPolyFromText in that case, or see ST_BuildArea() for a postgis-specific approach.

&sfs_compliant; s3.2.6.2

Availability: 1.1.0 - requires GEOS >= 2.1.0.

### Examples

    Forthcoming

### See Also

,

ST_BdMPolyFromText Construct a MultiPolygon given an arbitrary collection of closed linestrings as a MultiLineString text representation Well-Known text representation.
geometry `ST_BdMPolyFromText` text WKT integer srid

### Description

Construct a Polygon given an arbitrary collection of closed linestrings, polygons, MultiLineStrings as Well-Known text representation.

Throws an error if WKT is not a MULTILINESTRING. Forces MULTIPOLYGON output even when result is really only composed by a single POLYGON; use ST_BdPolyFromText if you're sure a single POLYGON will result from operation, or see ST_BuildArea() for a postgis-specific approach.

&sfs_compliant; s3.2.6.2

Availability: 1.1.0 - requires GEOS >= 2.1.0.

### Examples

    Forthcoming

### See Also

,

ST_GeogFromText Return a specified geography value from Well-Known Text representation or extended (WKT).
geography `ST_GeogFromText` text EWKT

### Description

Returns a geography object from the well-known text or extended well-known representation. SRID 4326 is assumed. This is an alias for ST_GeographyFromText

### Examples

    --- converting lon lat coords to geography
    ALTER TABLE sometable ADD COLUMN geog geography(POINT,4326);
    UPDATE sometable SET geog = ST_GeogFromText('SRID=4326;POINT(' || lon || ' ' || lat || ')');

### See Also

,

ST_GeographyFromText Return a specified geography value from Well-Known Text representation or extended (WKT).
geography `ST_GeographyFromText` text EWKT

### Description

Returns a geography object from the well-known text representation. SRID 4326 is assumed.

### See Also

ST_GeogFromWKB Creates a geography instance from a Well-Known Binary geometry representation (WKB) or extended Well Known Binary (EWKB).
geography `ST_GeogFromWKB` bytea geom

### Description

The `ST_GeogFromWKB` function, takes a well-known binary representation (WKB) of a geometry or PostGIS Extended WKB and creates an instance of the appropriate geography type. This function plays the role of the Geometry Factory in SQL.

If SRID is not specified, it defaults to 4326 (WGS 84 long lat).

&curve_support;

### Examples

    --Although bytea rep contains single \, these need to be escaped when inserting into a table
    SELECT ST_AsText(
    ST_GeogFromWKB(E'\\001\\002\\000\\000\\000\\002\\000\\000\\000\\037\\205\\353Q\\270~\\\\\\300\\323Mb\\020X\\231C@\\020X9\\264\\310~\\\\\\300)\\\\\\217\\302\\365\\230C@')
    );
    					  st_astext
    ------------------------------------------------------
     LINESTRING(-113.98 39.198,-113.981 39.195)
    (1 row)

### See Also

,

ST_GeomCollFromText Makes a collection Geometry from collection WKT with the given SRID. If SRID is not give, it defaults to -1.
geometry `ST_GeomCollFromText` text WKT integer srid geometry `ST_GeomCollFromText` text WKT

### Description

Makes a collection Geometry from the Well-Known-Text (WKT) representation with the given SRID. If SRID is not give, it defaults to -1.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite

Returns null if the WKT is not a GEOMETRYCOLLECTION

If you are absolutely sure all your WKT geometries are collections, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant;

### Examples

    SELECT ST_GeomCollFromText('GEOMETRYCOLLECTION(POINT(1 2),LINESTRING(1 2, 3 4))');

### See Also

,

ST_GeomFromEWKB Return a specified ST_Geometry value from Extended Well-Known Binary representation (EWKB).
geometry `ST_GeomFromEWKB` bytea EWKB

### Description

Constructs a PostGIS ST_Geometry object from the OGC Extended Well-Known binary (EWKT) representation.

The EWKB format is not an OGC standard, but a PostGIS specific format that includes the spatial reference system (SRID) identifier

&Z_support;

&curve_support;

### Examples

line string binary rep 0f LINESTRING(-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932) in NAD 83 long lat (4269).

NOTE: Even though byte arrays are delimited with \ and may have ', we need to escape both out with \ and ''. So it does not look exactly like its AsEWKB representation.

    SELECT ST_GeomFromEWKB(E'\\001\\002\\000\\000 \\255\\020\\000\\000\\003\\000\\000\\000\\344J=
    \\013B\\312Q\\300n\\303(\\010\\036!E@''\\277E''K
    \\312Q\\300\\366{b\\235*!E@\\225|\\354.P\\312Q
    \\300p\\231\\323e1!E@');

### See Also

, ,

ST_GeomFromEWKT Return a specified ST_Geometry value from Extended Well-Known Text representation (EWKT).
geometry `ST_GeomFromEWKT` text EWKT

### Description

Constructs a PostGIS ST_Geometry object from the OGC Extended Well-Known text (EWKT) representation.

The EWKT format is not an OGC standard, but an PostGIS specific format that includes the spatial reference system (SRID) identifier

&Z_support;

&curve_support;

### Examples

    SELECT ST_GeomFromEWKT('SRID=4269;LINESTRING(-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932)');
    SELECT ST_GeomFromEWKT('SRID=4269;MULTILINESTRING((-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932))');

    SELECT ST_GeomFromEWKT('SRID=4269;POINT(-71.064544 42.28787)');

    SELECT ST_GeomFromEWKT('SRID=4269;POLYGON((-71.1776585052917 42.3902909739571,-71.1776820268866 42.3903701743239,
    -71.1776063012595 42.3903825660754,-71.1775826583081 42.3903033653531,-71.1776585052917 42.3902909739571))');

    SELECT ST_GeomFromEWKT('SRID=4269;MULTIPOLYGON(((-71.1031880899493 42.3152774590236,
    -71.1031627617667 42.3152960829043,-71.102923838298 42.3149156848307,
    -71.1023097974109 42.3151969047397,-71.1019285062273 42.3147384934248,
    -71.102505233663 42.3144722937587,-71.10277487471 42.3141658254797,
    -71.103113945163 42.3142739188902,-71.10324876416 42.31402489987,
    -71.1033002961013 42.3140393340215,-71.1033488797549 42.3139495090772,
    -71.103396240451 42.3138632439557,-71.1041521907712 42.3141153348029,
    -71.1041411411543 42.3141545014533,-71.1041287795912 42.3142114839058,
    -71.1041188134329 42.3142693656241,-71.1041112482575 42.3143272556118,
    -71.1041072845732 42.3143851580048,-71.1041057218871 42.3144430686681,
    -71.1041065602059 42.3145009876017,-71.1041097995362 42.3145589148055,
    -71.1041166403905 42.3146168544148,-71.1041258822717 42.3146748022936,
    -71.1041375307579 42.3147318674446,-71.1041492906949 42.3147711126569,
    -71.1041598612795 42.314808571739,-71.1042515013869 42.3151287620809,
    -71.1041173835118 42.3150739481917,-71.1040809891419 42.3151344119048,
    -71.1040438678912 42.3151191367447,-71.1040194562988 42.3151832057859,
    -71.1038734225584 42.3151140942995,-71.1038446938243 42.3151006300338,
    -71.1038315271889 42.315094347535,-71.1037393329282 42.315054824985,
    -71.1035447555574 42.3152608696313,-71.1033436658644 42.3151648370544,
    -71.1032580383161 42.3152269126061,-71.103223066939 42.3152517403219,
    -71.1031880899493 42.3152774590236)),
    ((-71.1043632495873 42.315113108546,-71.1043583974082 42.3151211109857,
    -71.1043443253471 42.3150676015829,-71.1043850704575 42.3150793250568,-71.1043632495873 42.315113108546)))');

    --3d circular string
    SELECT ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)');

### See Also

, ,

ST_GeometryFromText Return a specified ST_Geometry value from Well-Known Text representation (WKT). This is an alias name for ST_GeomFromText
geometry `ST_GeometryFromText` text WKT geometry `ST_GeometryFromText` text WKT integer srid

### Description

&sfs_compliant;

&sqlmm_compliant; SQL-MM 3: 5.1.40

### See Also

ST_GeomFromGML Takes as input GML representation of geometry and outputs a PostGIS geometry object
geometry `ST_GeomFromGML` text geomgml

### Description

Constructs a PostGIS ST_Geometry object from the OGC GML representation.

ST_GeomFromGML works only for GML Geometry fragments. It throws an error if you try to use it on a whole GML document.

OGC GML versions supported:

- GML 3.2.1 Namespace

- GML 3.1.1 Simple Features profile SF-2 (with GML 3.1.0 and 3.0.0 backward compatibility)

- GML 2.1.2

OGC GML standards, cf: http://www.opengeospatial.org/standards/gml:

Availability: 1.5

&Z_support;

GML allow mixed dimensions (2D and 3D inside the same MultiGeometry for instance). As PostGIS geometries don't, ST_GeomFromGML convert the whole geometry to 2D if a missing Z dimension is found once.

GML support mixed SRS inside the same MultiGeometry. As PostGIS geometries don't, ST_GeomFromGML, in this case, reproject all subgeometries to the SRS root node. If no srsName attribute available for the GML root node, the function throw an error.

ST_GeomFromGML function is not pedantic about an explicit GML namespace. You could avoid to mention it explicitly for common usages. But you need it if you want to use XLink feature inside GML.

ST_GeomFromGML function not support SQL/MM curves geometries.

### Examples - A single geometry with srsName

    SELECT ST_GeomFromGML('
    		<gml:LineString srsName="EPSG:4269">
    			<gml:coordinates>
    				-71.16028,42.258729 -71.160837,42.259112 -71.161143,42.25932
    			</gml:coordinates>
    		</gml:LineString>');

### Examples - XLink usage

    ST_GeomFromGML('
    		<gml:LineString xmlns:gml="http://www.opengis.net/gml"
    				xmlns:xlink="http://www.w3.org/1999/xlink"
    				srsName="urn:ogc:def:crs:EPSG::4269">
    			<gml:pointProperty>
    				<gml:Point gml:id="p1"><gml:pos>42.258729 -71.16028</gml:pos></gml:Point>
    			</gml:pointProperty>
    			<gml:pos>42.259112 -71.160837</gml:pos>
    			<gml:pointProperty>
    				<gml:Point xlink:type="simple" xlink:href="#p1"/>
    			</gml:pointProperty>
    		</gml:LineString>'););

### See Also

ST_GeomFromKML Takes as input KML representation of geometry and outputs a PostGIS geometry object
geometry `ST_GeomFromKML` text geomkml

### Description

Constructs a PostGIS ST_Geometry object from the OGC KML representation.

ST_GeomFromKML works only for KML Geometry fragments. It throws an error if you try to use it on a whole KML document.

OGC KML versions supported:

- KML 2.2.0 Namespace

OGC KML standards, cf: http://www.opengeospatial.org/standards/kml:

Availability: 1.5

&Z_support;

ST_GeomFromKML function not support SQL/MM curves geometries.

### Examples - A single geometry with srsName

    SELECT ST_GeomFromKML('
    		<LineString>
    			<coordinates>-71.1663,42.2614
    				-71.1667,42.2616</coordinates>
    		</LineString>');

### See Also

ST_GMLToSQL Return a specified ST_Geometry value from GML representation. This is an alias name for ST_GeomFromGML
geometry `ST_GMLToSQL` text geomgml

### Description

&sqlmm_compliant; SQL-MM 3: 5.1.50 (except for curves support).

Availability: 1.5

### See Also

ST_GeomFromText Return a specified ST_Geometry value from Well-Known Text representation (WKT).
geometry `ST_GeomFromText` text WKT geometry `ST_GeomFromText` text WKT integer srid

### Description

Constructs a PostGIS ST_Geometry object from the OGC Well-Known text representation.

There are 2 variants of ST_GeomFromText function, the first takes no SRID and returns a geometry with no defined spatial reference system. The second takes a spatial reference id as the second argument and returns an ST_Geometry that includes this srid as part of its meta-data. The srid must be defined in the spatial_ref_sys table.

&sfs_compliant; s3.2.6.2 - option SRID is from the conformance suite.

&sqlmm_compliant; SQL-MM 3: 5.1.40

&curve_support;

### Examples

    SELECT ST_GeomFromText('LINESTRING(-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932)');
    SELECT ST_GeomFromText('LINESTRING(-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932)',4269);

    SELECT ST_GeomFromText('MULTILINESTRING((-71.160281 42.258729,-71.160837 42.259113,-71.161144 42.25932))');

    SELECT ST_GeomFromText('POINT(-71.064544 42.28787)');

    SELECT ST_GeomFromText('POLYGON((-71.1776585052917 42.3902909739571,-71.1776820268866 42.3903701743239,
    -71.1776063012595 42.3903825660754,-71.1775826583081 42.3903033653531,-71.1776585052917 42.3902909739571))');

    SELECT ST_GeomFromText('MULTIPOLYGON(((-71.1031880899493 42.3152774590236,
    -71.1031627617667 42.3152960829043,-71.102923838298 42.3149156848307,
    -71.1023097974109 42.3151969047397,-71.1019285062273 42.3147384934248,
    -71.102505233663 42.3144722937587,-71.10277487471 42.3141658254797,
    -71.103113945163 42.3142739188902,-71.10324876416 42.31402489987,
    -71.1033002961013 42.3140393340215,-71.1033488797549 42.3139495090772,
    -71.103396240451 42.3138632439557,-71.1041521907712 42.3141153348029,
    -71.1041411411543 42.3141545014533,-71.1041287795912 42.3142114839058,
    -71.1041188134329 42.3142693656241,-71.1041112482575 42.3143272556118,
    -71.1041072845732 42.3143851580048,-71.1041057218871 42.3144430686681,
    -71.1041065602059 42.3145009876017,-71.1041097995362 42.3145589148055,
    -71.1041166403905 42.3146168544148,-71.1041258822717 42.3146748022936,
    -71.1041375307579 42.3147318674446,-71.1041492906949 42.3147711126569,
    -71.1041598612795 42.314808571739,-71.1042515013869 42.3151287620809,
    -71.1041173835118 42.3150739481917,-71.1040809891419 42.3151344119048,
    -71.1040438678912 42.3151191367447,-71.1040194562988 42.3151832057859,
    -71.1038734225584 42.3151140942995,-71.1038446938243 42.3151006300338,
    -71.1038315271889 42.315094347535,-71.1037393329282 42.315054824985,
    -71.1035447555574 42.3152608696313,-71.1033436658644 42.3151648370544,
    -71.1032580383161 42.3152269126061,-71.103223066939 42.3152517403219,
    -71.1031880899493 42.3152774590236)),
    ((-71.1043632495873 42.315113108546,-71.1043583974082 42.3151211109857,
    -71.1043443253471 42.3150676015829,-71.1043850704575 42.3150793250568,-71.1043632495873 42.315113108546)))',4326);

    SELECT ST_GeomFromText('CIRCULARSTRING(220268 150415,220227 150505,220227 150406)');

### See Also

, ,

ST_GeomFromWKB Creates a geometry instance from a Well-Known Binary geometry representation (WKB) and optional SRID.
geometry `ST_GeomFromWKB` bytea geom geometry `ST_GeomFromWKB` bytea geom integer srid

### Description

The `ST_GeomFromWKB` function, takes a well-known binary representation of a geometry and a Spatial Reference System ID (`SRID`) and creates an instance of the appropriate geometry type. This function plays the role of the Geometry Factory in SQL. This is an alternate name for ST_WKBToSQL.

If SRID is not specified, it defaults to -1 (Unknown).

&sfs_compliant; s3.2.7.2 - the optional SRID is from the conformance suite

&sqlmm_compliant; SQL-MM 3: 5.1.41

&curve_support;

### Examples

    --Although bytea rep contains single \, these need to be escaped when inserting into a table
    SELECT ST_AsEWKT(
    ST_GeomFromWKB(E'\\001\\002\\000\\000\\000\\002\\000\\000\\000\\037\\205\\353Q\\270~\\\\\\300\\323Mb\\020X\\231C@\\020X9\\264\\310~\\\\\\300)\\\\\\217\\302\\365\\230C@',4326)
    );
    					  st_asewkt
    ------------------------------------------------------
     SRID=4326;LINESTRING(-113.98 39.198,-113.981 39.195)
    (1 row)

    SELECT
      ST_AsText(
    	ST_GeomFromWKB(
    	  ST_AsEWKB('POINT(2 5)'::geometry)
    	)
      );
     st_astext
    ------------
     POINT(2 5)
    (1 row)

### See Also

, ,

ST_LineFromMultiPoint Creates a LineString from a MultiPoint geometry.
geometry `ST_LineFromMultiPoint` geometry aMultiPoint

### Description

Creates a LineString from a MultiPoint geometry.

&Z_support;

### Examples

    --Create a 3d line string from a 3d multipoint
    SELECT ST_AsEWKT(ST_LineFromMultiPoint(ST_GeomFromEWKT('MULTIPOINT(1 2 3, 4 5 6, 7 8 9)')));
    --result--
    LINESTRING(1 2 3,4 5 6,7 8 9)

### See Also

, ,

ST_LineFromText Makes a Geometry from WKT representation with the given SRID. If SRID is not given, it defaults to -1.
geometry `ST_LineFromText` text WKT geometry `ST_LineFromText` text WKT integer srid

### Description

Makes a Geometry from WKT with the given SRID. If SRID is not give, it defaults to -1. If WKT passed in is not a LINESTRING, then null is returned.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite.

If you know all your geometries are LINESTRINGS, its more efficient to just use ST_GeomFromText. This just calls ST_GeomFromText and adds additional validation that it returns a linestring.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant; SQL-MM 3: 7.2.8

### Examples

    SELECT ST_LineFromText('LINESTRING(1 2, 3 4)') AS aline, ST_LineFromText('POINT(1 2)') AS null_return;
    aline                            | null_return
    ------------------------------------------------
    010200000002000000000000000000F ... | t

### See Also

ST_LineFromWKB Makes a `LINESTRING` from WKB with the given SRID
geometry `ST_LineFromWKB` bytea WKB geometry `ST_LineFromWKB` bytea WKB integer srid

### Description

The `ST_LineFromWKB` function, takes a well-known binary representation of geometry and a Spatial Reference System ID (`SRID`) and creates an instance of the appropriate geometry type - in this case, a `LINESTRING` geometry. This function plays the role of the Geometry Factory in SQL.

If an SRID is not specified, it defaults to -1. `NULL` is returned if the input `bytea` does not represent a `LINESTRING`.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite.

If you know all your geometries are `LINESTRING`s, its more efficient to just use . This function just calls and adds additional validation that it returns a linestring.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant; SQL-MM 3: 7.2.9

### Examples

    SELECT ST_LineFromWKB(ST_AsBinary(ST_GeomFromText('LINESTRING(1 2, 3 4)'))) AS aline,
    		ST_LineFromWKB(ST_AsBinary(ST_GeomFromText('POINT(1 2)'))) IS NULL AS null_return;
    aline                            | null_return
    ------------------------------------------------
    010200000002000000000000000000F ... | t

### See Also

,

ST_LinestringFromWKB Makes a geometry from WKB with the given SRID.
geometry `ST_LinestringFromWKB` bytea WKB geometry `ST_LinestringFromWKB` bytea WKB integer srid

### Description

The `ST_LinestringFromWKB` function, takes a well-known binary representation of geometry and a Spatial Reference System ID (`SRID`) and creates an instance of the appropriate geometry type - in this case, a `LINESTRING` geometry. This function plays the role of the Geometry Factory in SQL.

If an SRID is not specified, it defaults to -1. `NULL` is returned if the input `bytea` does not represent a `LINESTRING` geometry. This an alias for .

OGC SPEC 3.2.6.2 - optional SRID is from the conformance suite.

If you know all your geometries are `LINESTRING`s, it's more efficient to just use . This function just calls and adds additional validation that it returns a `LINESTRING`.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant; SQL-MM 3: 7.2.9

### Examples

    SELECT
      ST_LineStringFromWKB(
    	ST_AsBinary(ST_GeomFromText('LINESTRING(1 2, 3 4)'))
      ) AS aline,
      ST_LinestringFromWKB(
    	ST_AsBinary(ST_GeomFromText('POINT(1 2)'))
      ) IS NULL AS null_return;
       aline                            | null_return
    ------------------------------------------------
    010200000002000000000000000000F ... | t

### See Also

,

ST_MakeBox2D Creates a BOX2D defined by the given point geometries.
box2d `ST_MakeBox2D` geometry pointLowLeft geometry pointUpRight

### Description

Creates a BOX2D defined by the given point geometries. This is useful for doing range queries

### Examples

    --Return all features that fall reside or partly reside in a US national atlas coordinate bounding box
    --It is assumed here that the geometries are stored with SRID = 2163 (US National atlas equal area)
    SELECT feature_id, feature_name, the_geom
    FROM features
    WHERE the_geom && ST_SetSRID(ST_MakeBox2D(ST_Point(-989502.1875, 528439.5625),
    	ST_Point(-987121.375 ,529933.1875)),2163)

### See Also

, , ,

ST_MakeBox3D Creates a BOX3D defined by the given 3d point geometries.
box3d `ST_MakeBox3D` geometry point3DLowLeftBottom geometry point3DUpRightTop

### Description

Creates a BOX3D defined by the given 2 3D point geometries.

This function supports 3d and will not drop the z-index.

### Examples

    SELECT ST_MakeBox3D(ST_MakePoint(-989502.1875, 528439.5625, 10),
    	ST_MakePoint(-987121.375 ,529933.1875, 10)) As abb3d

    --bb3d--
    --------
    BOX3D(-989502.1875 528439.5625 10,-987121.375 529933.1875 10)

### See Also

, ,

ST_MakeLine Creates a Linestring from point geometries.
geometry `ST_MakeLine` geometry set pointfield geometry `ST_MakeLine` geometry point1 geometry point2 geometry `ST_MakeLine` geometry[] point_array

### Description

ST_MakeLine comes in 3 forms: a spatial aggregate that takes rows of point geometries and returns a line string, a function that takes an array of points, and a regular function that takes two point geometries. You might want to use a subselect to order points before feeding them to the aggregate version of this function.

&Z_support;

Availability: 1.4.0 - ST_MakeLine(geomarray) was introduced. ST_MakeLine aggregate functions was enhanced to handle more points faster.

### Examples: Spatial Aggregate version

This example takes a sequence of GPS points and creates one record for each gps travel where the geometry field is a line string composed of the gps points in the order of the travel.

    SELECT gps.gps_track, ST_MakeLine(gps.the_geom) As newgeom
    	FROM (SELECT gps_track,gps_time, the_geom
    			FROM gps_points ORDER BY gps_track, gps_time) As gps
    	GROUP BY gps.gps_track

### Examples: Non-Spatial Aggregate version

First example is a simple one off line string composed of 2 points. The second formulates line strings from 2 points a user draws. The third is a one-off that joins 2 3d points to create a line in 3d space.

    SELECT ST_AsText(ST_MakeLine(ST_MakePoint(1,2), ST_MakePoint(3,4)));
    	  st_astext
    ---------------------
     LINESTRING(1 2,3 4)

    SELECT userpoints.id, ST_MakeLine(startpoint, endpoint) As drawn_line
    	FROM userpoints ;

    SELECT ST_AsEWKT(ST_MakeLine(ST_MakePoint(1,2,3), ST_MakePoint(3,4,5)));
    		st_asewkt
    -------------------------
     LINESTRING(1 2 3,3 4 5)

### Examples: Using Array version

    SELECT ST_MakeLine(ARRAY(SELECT ST_Centroid(the_geom) FROM visit_locations ORDER BY visit_time));

    --Making a 3d line with 3 3-d points
    SELECT ST_AsEWKT(ST_MakeLine(ARRAY[ST_MakePoint(1,2,3),
    				ST_MakePoint(3,4,5), ST_MakePoint(6,6,6)]));
    		st_asewkt
    -------------------------
    LINESTRING(1 2 3,3 4 5,6 6 6)

### See Also

, , ,

ST_MakeEnvelope Creates a rectangular Polygon formed from the given minimums and maximums. Input values must be in SRS specified by the SRID.
geometry `ST_MakeEnvelope` double precision xmin double precision ymin double precision xmax double precision ymax integer srid

### Description

Creates a rectangular Polygon formed from the minima and maxima. by the given shell. Input values must be in SRS specified by the SRID.

Availability: 1.5

### Example: Building a bounding box polygon

    SELECT ST_AsText(ST_MakeEnvelope(10, 10, 11, 11, 4326));

    st_asewkt
    -----------
    POLYGON((10 10, 10 11, 11 11, 11 10, 10 10))

### See Also

, ,

ST_MakePolygon Creates a Polygon formed by the given shell. Input geometries must be closed LINESTRINGS.
geometry `ST_MakePolygon` geometry linestring geometry `ST_MakePolygon` geometry outerlinestring geometry[] interiorlinestrings

### Description

Creates a Polygon formed by the given shell. Input geometries must be closed LINESTRINGS. Comes in 2 variants.

Variant 1: takes one closed linestring.

Variant 2: Creates a Polygon formed by the given shell and array of holes. You can construct a geometry array using ST_Accum or the PostgreSQL ARRAY[] and ARRAY() constructs. Input geometries must be closed LINESTRINGS.

This function will not accept a MULTILINESTRING. Use or to generate line strings.

&Z_support;

### Examples: Single closed LINESTRING

    --2d line
    SELECT ST_MakePolygon(ST_GeomFromText('LINESTRING(75.15 29.53,77 29,77.6 29.5, 75.15 29.53)'));
    --If linestring is not closed
    --you can add the start point to close it
    SELECT ST_MakePolygon(ST_AddPoint(foo.open_line, ST_StartPoint(foo.open_line)))
    FROM (
    SELECT ST_GeomFromText('LINESTRING(75.15 29.53,77 29,77.6 29.5)') As open_line) As foo;

    --3d closed line
    SELECT ST_MakePolygon(ST_GeomFromText('LINESTRING(75.15 29.53 1,77 29 1,77.6 29.5 1, 75.15 29.53 1)'));

    st_asewkt
    -----------
    POLYGON((75.15 29.53 1,77 29 1,77.6 29.5 1,75.15 29.53 1))

    --measured line --
    SELECT ST_MakePolygon(ST_GeomFromText('LINESTRINGM(75.15 29.53 1,77 29 1,77.6 29.5 2, 75.15 29.53 2)'));

    st_asewkt
    ----------
    POLYGONM((75.15 29.53 1,77 29 1,77.6 29.5 2,75.15 29.53 2))

### Examples: Outter shell with inner shells

Build a donut with an ant hole

    SELECT ST_MakePolygon(
    		ST_ExteriorRing(ST_Buffer(foo.line,10)),
    	ARRAY[ST_Translate(foo.line,1,1),
    		ST_ExteriorRing(ST_Buffer(ST_MakePoint(20,20),1)) ]
    	)
    FROM
    	(SELECT ST_ExteriorRing(ST_Buffer(ST_MakePoint(10,10),10,10))
    		As line )
    		As foo;

Build province boundaries with holes representing lakes in the province from a set of province polygons/multipolygons and water line strings this is an example of using PostGIS ST_Accum

The use of CASE because feeding a null array into ST_MakePolygon results in NULL

the use of left join to guarantee we get all provinces back even if they have no lakes

    	SELECT p.gid, p.province_name,
    		CASE WHEN
    			ST_Accum(w.the_geom) IS NULL THEN p.the_geom
    		ELSE  ST_MakePolygon(ST_LineMerge(ST_Boundary(p.the_geom)), ST_Accum(w.the_geom)) END
    	FROM
    		provinces p LEFT JOIN waterlines w
    			ON (ST_Within(w.the_geom, p.the_geom) AND ST_IsClosed(w.the_geom))
    	GROUP BY p.gid, p.province_name, p.the_geom;

    	--Same example above but utilizing a correlated subquery
    	--and PostgreSQL built-in ARRAY() function that converts a row set to an array

    	SELECT p.gid,  p.province_name, CASE WHEN
    		EXISTS(SELECT w.the_geom
    			FROM waterlines w
    			WHERE ST_Within(w.the_geom, p.the_geom)
    			AND ST_IsClosed(w.the_geom))
    		THEN
    		ST_MakePolygon(ST_LineMerge(ST_Boundary(p.the_geom)),
    			ARRAY(SELECT w.the_geom
    				FROM waterlines w
    				WHERE ST_Within(w.the_geom, p.the_geom)
    				AND ST_IsClosed(w.the_geom)))
    		ELSE p.the_geom END As the_geom
    	FROM
    		provinces p;

### See Also

, , , ,

ST_MakePoint Creates a 2D,3DZ or 4D point geometry.
geometry `ST_MakePoint` double precision x double precision y geometry `ST_MakePoint` double precision x double precision y double precision z geometry `ST_MakePoint` double precision x double precision y double precision z double precision m

### Description

Creates a 2D,3DZ or 4D point geometry (geometry with measure). `ST_MakePoint` while not being OGC compliant is generally faster and more precise than and . It is also easier to use if you have raw coordinates rather than WKT.

Note x is longitude and y is latitude

Use if you need to make a point with x,y,m.

&Z_support;

### Examples

    --Return point with unknown SRID
    SELECT ST_MakePoint(-71.1043443253471, 42.3150676015829);

    --Return point marked as WGS 84 long lat
    SELECT ST_SetSRID(ST_MakePoint(-71.1043443253471, 42.3150676015829),4326);

    --Return a 3D point (e.g. has altitude)
    SELECT ST_MakePoint(1, 2,1.5);

    --Get z of point
    SELECT ST_Z(ST_MakePoint(1, 2,1.5));
    result
    -------
    1.5

### See Also

, , ,

ST_MakePointM Creates a point geometry with an x y and m coordinate.
geometry `ST_MakePointM` float x float y float m

### Description

Creates a point with x, y and measure coordinates.

Note x is longitude and y is latitude.

### Examples

We use ST_AsEWKT in these examples to show the text representation instead of ST_AsText because ST_AsText does not support returning M.

    --Return EWKT representation of point with unknown SRID
    SELECT ST_AsEWKT(ST_MakePointM(-71.1043443253471, 42.3150676015829, 10));

    --result
    				   st_asewkt
    -----------------------------------------------
     POINTM(-71.1043443253471 42.3150676015829 10)

    --Return EWKT representation of point with measure marked as WGS 84 long lat
    SELECT ST_AsEWKT(ST_SetSRID(ST_MakePointM(-71.1043443253471, 42.3150676015829,10),4326));

    						st_asewkt
    ---------------------------------------------------------
    SRID=4326;POINTM(-71.1043443253471 42.3150676015829 10)

    --Return a 3d point (e.g. has altitude)
    SELECT ST_MakePoint(1, 2,1.5);

    --Get m of point
    SELECT ST_M(ST_MakePointM(-71.1043443253471, 42.3150676015829,10));
    result
    -------
    10

### See Also

, ,

ST_MLineFromText Return a specified ST_MultiLineString value from WKT representation.
geometry `ST_MLineFromText` text WKT integer srid geometry `ST_MLineFromText` text WKT

### Description

Makes a Geometry from Well-Known-Text (WKT) with the given SRID. If SRID is not give, it defaults to -1.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite

Returns null if the WKT is not a MULTILINESTRING

If you are absolutely sure all your WKT geometries are points, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant;SQL-MM 3: 9.4.4

### Examples

    SELECT ST_MLineFromText('MULTILINESTRING((1 2, 3 4), (4 5, 6 7))');

### See Also

ST_MPointFromText Makes a Geometry from WKT with the given SRID. If SRID is not give, it defaults to -1.
geometry `ST_MPointFromText` text WKT integer srid geometry `ST_MPointFromText` text WKT

### Description

Makes a Geometry from WKT with the given SRID. If SRID is not give, it defaults to -1.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite

Returns null if the WKT is not a MULTIPOINT

If you are absolutely sure all your WKT geometries are points, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step.

&sfs_compliant; 3.2.6.2

&sqlmm_compliant; SQL-MM 3: 9.2.4

### Examples

    SELECT ST_MPointFromText('MULTIPOINT(1 2, 3 4)');
    SELECT ST_MPointFromText('MULTIPOINT(-70.9590 42.1180, -70.9611 42.1223)', 4326);

### See Also

ST_MPolyFromText Makes a MultiPolygon Geometry from WKT with the given SRID. If SRID is not give, it defaults to -1.
geometry `ST_MPolyFromText` text WKT integer srid geometry `ST_MPolyFromText` text WKT

### Description

Makes a MultiPolygon from WKT with the given SRID. If SRID is not give, it defaults to -1.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite

Throws an error if the WKT is not a MULTIPOLYGON

If you are absolutely sure all your WKT geometries are multipolygons, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant; SQL-MM 3: 9.6.4

### Examples

    SELECT ST_MPolyFromText('MULTIPOLYGON(((0 0 1,20 0 1,20 20 1,0 20 1,0 0 1),(5 5 3,5 7 3,7 7 3,7 5 3,5 5 3)))');
    SELECt ST_MPolyFromText('MULTIPOLYGON(((-70.916 42.1002,-70.9468 42.0946,-70.9765 42.0872,-70.9754 42.0875,-70.9749 42.0879,-70.9752 42.0881,-70.9754 42.0891,-70.9758 42.0894,-70.9759 42.0897,-70.9759 42.0899,-70.9754 42.0902,-70.9756 42.0906,-70.9753 42.0907,-70.9753 42.0917,-70.9757 42.0924,-70.9755 42.0928,-70.9755 42.0942,-70.9751 42.0948,-70.9755 42.0953,-70.9751 42.0958,-70.9751 42.0962,-70.9759 42.0983,-70.9767 42.0987,-70.9768 42.0991,-70.9771 42.0997,-70.9771 42.1003,-70.9768 42.1005,-70.977 42.1011,-70.9766 42.1019,-70.9768 42.1026,-70.9769 42.1033,-70.9775 42.1042,-70.9773 42.1043,-70.9776 42.1043,-70.9778 42.1048,-70.9773 42.1058,-70.9774 42.1061,-70.9779 42.1065,-70.9782 42.1078,-70.9788 42.1085,-70.9798 42.1087,-70.9806 42.109,-70.9807 42.1093,-70.9806 42.1099,-70.9809 42.1109,-70.9808 42.1112,-70.9798 42.1116,-70.9792 42.1127,-70.979 42.1129,-70.9787 42.1134,-70.979 42.1139,-70.9791 42.1141,-70.9987 42.1116,-71.0022 42.1273,
    	-70.9408 42.1513,-70.9315 42.1165,-70.916 42.1002)))',4326);

### See Also

,

ST_Point Returns an ST_Point with the given coordinate values. OGC alias for ST_MakePoint.
geometry `ST_Point` float x_lon float y_lat

### Description

Returns an ST_Point with the given coordinate values. MM compliant alias for ST_MakePoint that takes just an x and y.

&sqlmm_compliant; SQL-MM 3: 6.1.2

### Examples: Geometry

    SELECT ST_SetSRID(ST_Point(-71.1043443253471, 42.3150676015829),4326)

### Examples: Geography

    SELECT CAST(ST_SetSRID(ST_Point(-71.1043443253471, 42.3150676015829),4326) As geography);

    -- the :: is PostgreSQL short-hand for casting.
    SELECT ST_SetSRID(ST_Point(-71.1043443253471, 42.3150676015829),4326)::geography;

    --If your point coordinates are in a different spatial reference from WGS-84 long lat, then you need to transform before casting
    -- This example we convert a point in Pennsylvania State Plane feet to WGS 84 and then geography
    SELECT ST_Transform(ST_SetSRID(ST_Point(3637510, 3014852),2273),4326)::geography

;

### See Also

, , ,

ST_PointFromText Makes a point Geometry from WKT with the given SRID. If SRID is not given, it defaults to unknown.
geometry `ST_PointFromText` text WKT geometry `ST_PointFromText` text WKT integer srid

### Description

Constructs a PostGIS ST_Geometry point object from the OGC Well-Known text representation. If SRID is not give, it defaults to unknown (currently -1). If geometry is not a WKT point representation, returns null. If completely invalid WKT, then throws an error.

There are 2 variants of ST_PointFromText function, the first takes no SRID and returns a geometry with no defined spatial reference system. The second takes a spatial reference id as the second argument and returns an ST_Geometry that includes this srid as part of its meta-data. The srid must be defined in the spatial_ref_sys table.

If you are absolutely sure all your WKT geometries are points, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step. If you are building points from long lat coordinates and care more about performance and accuracy than OGC compliance, use or OGC compliant alias .

&sfs_compliant; s3.2.6.2 - option SRID is from the conformance suite.

&sqlmm_compliant; SQL-MM 3: 6.1.8

### Examples

    SELECT ST_PointFromText('POINT(-71.064544 42.28787)');
    SELECT ST_PointFromText('POINT(-71.064544 42.28787)', 4326);

### See Also

, , ,

ST_PointFromWKB Makes a geometry from WKB with the given SRID
geometry `ST_GeomFromWKB` bytea geom geometry `ST_GeomFromWKB` bytea geom integer srid

### Description

The `ST_PointFromWKB` function, takes a well-known binary representation of geometry and a Spatial Reference System ID (`SRID`) and creates an instance of the appropriate geometry type - in this case, a `POINT` geometry. This function plays the role of the Geometry Factory in SQL.

If an SRID is not specified, it defaults to -1. `NULL` is returned if the input `bytea` does not represent a `POINT` geometry.

&sfs_compliant; s3.2.7.2

&sqlmm_compliant; SQL-MM 3: 6.1.9

&Z_support;

&curve_support;

### Examples

    SELECT
      ST_AsText(
    	ST_PointFromWKB(
    	  ST_AsEWKB('POINT(2 5)'::geometry)
    	)
      );
     st_astext
    ------------
     POINT(2 5)
    (1 row)

    SELECT
      ST_AsText(
    	ST_PointFromWKB(
    	  ST_AsEWKB('LINESTRING(2 5, 2 6)'::geometry)
    	)
      );
     st_astext
    -----------

    (1 row)

### See Also

,

ST_Polygon Returns a polygon built from the specified linestring and SRID.
geometry `ST_Polygon` geometry aLineString integer srid

### Description

Returns a polygon built from the specified linestring and SRID.

ST_Polygon is similar to first version oST_MakePolygon except it also sets the spatial ref sys (SRID) of the polygon. Will not work with MULTILINESTRINGS so use LineMerge to merge multilines. Also does not create polygons with holes. Use ST_MakePolygon for that.

&sfs_compliant;

&sqlmm_compliant; SQL-MM 3: 8.3.2

&Z_support;

### Examples

    --a 2d polygon
    SELECT ST_Polygon(ST_GeomFromText('LINESTRING(75.15 29.53,77 29,77.6 29.5, 75.15 29.53)'), 4326);

    --result--
    POLYGON((75.15 29.53,77 29,77.6 29.5,75.15 29.53))
    --a 3d polygon
    SELECT ST_AsEWKT(ST_Polygon(ST_GeomFromEWKT('LINESTRING(75.15 29.53 1,77 29 1,77.6 29.5 1, 75.15 29.53 1)'), 4326));

    result
    ------
    SRID=4326;POLYGON((75.15 29.53 1,77 29 1,77.6 29.5 1,75.15 29.53 1))

### See Also

, , , , ,

ST_PolygonFromText Makes a Geometry from WKT with the given SRID. If SRID is not give, it defaults to -1.
geometry `ST_PolygonFromText` text WKT geometry `ST_PolygonFromText` text WKT integer srid

### Description

Makes a Geometry from WKT with the given SRID. If SRID is not give, it defaults to -1. Returns null if WKT is not a polygon.

OGC SPEC 3.2.6.2 - option SRID is from the conformance suite

If you are absolutely sure all your WKT geometries are polygons, don't use this function. It is slower than ST_GeomFromText since it adds an additional validation step.

&sfs_compliant; s3.2.6.2

&sqlmm_compliant; SQL-MM 3: 8.3.6

### Examples

    SELECT ST_PolygonFromText('POLYGON((-71.1776585052917 42.3902909739571,-71.1776820268866 42.3903701743239,
    -71.1776063012595 42.3903825660754,-71.1775826583081 42.3903033653531,-71.1776585052917 42.3902909739571))');
    st_polygonfromtext
    ------------------
    010300000001000000050000006...

    SELECT ST_PolygonFromText('POINT(1 2)') IS NULL as point_is_notpoly;

    point_is_not_poly
    ----------
    t

### See Also

ST_WKBToSQL Return a specified ST_Geometry value from Well-Known Binary representation (WKB). This is an alias name for ST_GeomFromWKB that takes no srid
geometry `ST_WKBToSQL` bytea WKB

### Description

&sqlmm_compliant; SQL-MM 3: 5.1.36

### See Also

ST_WKTToSQL Return a specified ST_Geometry value from Well-Known Text representation (WKT). This is an alias name for ST_GeomFromText
geometry `ST_WKTToSQL` text WKT

### Description

&sqlmm_compliant; SQL-MM 3: 5.1.34

### See Also