I'm new to postGIS and am having trouble finding an answer to this question. I have loaded UK postcode data (OSGB36, SRID 27700 with eastings and northings fields) into a postGIS database. I now want to generate a geom column to store the point information.
I can find some clear instructions on how to do this using ST_MakePoint from here: http://twiav-tt.blogspot.co.uk/2012/07/postgis-using-latitude-and-longitude-to.html
This gives the nice straightforward syntax example of:
UPDATE netherlands.airports SET geom = ST_SetSRID(ST_MakePoint(longitude,latitude),4326);I've read that although ST_MakePoint is fast, it's not as standards compliant/transferable as ST_PointFromText.
But no matter where I look for a similar example for ST_PointFromText, I can't find one. For example, on Boston GIS, the following example is given:
UPDATE points_of_interest SET thepoint_lonlat = PointFromText('POINT(' || longitude || ' ' || latitude || ')',4326)The postGIS page gives a near identical example:
SELECT ST_PointFromText('POINT(-71.064544 42.28787)', 4326);These previous two example just seem to show you how to generate a point for some text that you've hand-typed in, they don't show you the syntax for how to derive it from other fields in your table.
So I know I'm being a noob here, but I have one column called 'easting' and one column called 'northing'. What is the syntax to create my geom column using ST_PointFromText?
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I can find some clear instructions on how to do this using ST_MakePoint from here: http://twiav-tt.blogspot.co.uk/2012/07/postgis-using-latitude-and-longitude-to.html
This gives the nice straightforward syntax example of:
UPDATE netherlands.airports SET geom = ST_SetSRID(ST_MakePoint(longitude,latitude),4326);I've read that although ST_MakePoint is fast, it's not as standards compliant/transferable as ST_PointFromText.
But no matter where I look for a similar example for ST_PointFromText, I can't find one. For example, on Boston GIS, the following example is given:
UPDATE points_of_interest SET thepoint_lonlat = PointFromText('POINT(' || longitude || ' ' || latitude || ')',4326)The postGIS page gives a near identical example:
SELECT ST_PointFromText('POINT(-71.064544 42.28787)', 4326);These previous two example just seem to show you how to generate a point for some text that you've hand-typed in, they don't show you the syntax for how to derive it from other fields in your table.
So I know I'm being a noob here, but I have one column called 'easting' and one column called 'northing'. What is the syntax to create my geom column using ST_PointFromText?
أكثر...