I have a table in MySQL that has polygon defined. Read MySQL 5.6 geospatial index documentation and came across ST_Area
function. Tried to dig into the units which are computed as per the spatial reference system. I am not sure how to convert the output to square meters.
CREATE TABLE Area (
polygon
polygon NOT NULL,
Name VARCHAR(100),
SPATIAL KEY Polygon
(Polygon
)
);
INSERT INTO Area(polygon, Name) VALUES ('POLYGON((27.55858717457406 76.6309398865454,27.493737501738696 76.6305965637915,27.49130108815994 76.67728845832275,27.496173861399882 76.69376795051025,27.516576256439183 76.69720117804931,27.536366008597625 76.69273798224853,27.55858717457406 76.6309398865454))', 'area1'); INSERT INTO Area(polygon, Name) VALUES ('POLYGON((18.311749294999043 78.27789997153775,18.293169874823796 78.35446094565884,18.30571935075326 78.3462211995651,18.315538274143172 78.34010576301114,18.323727074736937 78.3350202947189,18.322240082529422 78.32786416106717,18.32071233749967 78.32079385810391,18.31696421255629 78.3030698209335,18.312849329745635 78.28360771232144,18.311749294999043 78.27789997153775))', 'area2');
select ST_Area(polygon) from Area;// not sure what is the result output.
CREATE TABLE Area (
`polygon` polygon NOT NULL,
Name VARCHAR(100),
SPATIAL KEY `Polygon` (`Polygon`)
);
INSERT INTO Area(polygon, Name) VALUES ('POLYGON((27.55858717457406
76.6309398865454,27.493737501738696 76.6305965637915,27.49130108815994
76.67728845832275,27.496173861399882 76.69376795051025,27.516576256439183
76.69720117804931,27.536366008597625 76.69273798224853,27.55858717457406
76.6309398865454))', 'area1');
INSERT INTO Area(polygon, Name) VALUES ('POLYGON((18.311749294999043
78.27789997153775,18.293169874823796 78.35446094565884,18.30571935075326
78.3462211995651,18.315538274143172 78.34010576301114,18.323727074736937
78.3350202947189,18.322240082529422 78.32786416106717,18.32071233749967
78.32079385810391,18.31696421255629 78.3030698209335,18.312849329745635
78.28360771232144,18.311749294999043 78.27789997153775))', 'area2');
select ST_Area(polygon) from Area; /* not sure what is the result output. */