Taking coords from Google Maps and inserting it in PostgreSQL

Question

My question is pretty basic. I am using Android Google Maps to take the coordinates off a location on the map and I want to insert it into a PostgreSQL database. I know I have to use PostGIS but how can I do that? Who can point me in the right direction?

My insertion query in Java looks like:

String query = "INSERT INTO modul (denumire, adresa, tip_retea, geom, poza)";
query += " VALUES ('" 
     + getset.getDenumire() + "', '" 
     + getset.getAdresa() + "', '"
     + getset.getTipretea()+ "', 
     ST_PointFromText('point(" + point.getX() + " " + point.getY()+ ")', 1), '" 
     + getset.getImagine() + "');";

Which generates me the following query:

INSERT INTO modul (denumire, adresa, tip_retea, geom, poza) VALUES ('', '', '', ST_PointFromText('point(23.78977 44.320948)', 1), 'irrelevant b64 encoded image');

But how can I properly insert the coordinates into a database? What datatype does the column 'geom' need to be? Thank you in advance.

Answer 1

As Igor has pointed out in the comments, your approach of concatenating strings into SQL statements is open to SQL injection. You can avoid this by using prepared statements in Java.

//prepare a statement -- omitting the non geometry values from OP question for clarity
String sql = "Insert into modul (geom) values (ST_MakePoint(?, ?))";
PreparedStatement stmt = conn.prepareStatement(sql);
//add the actual x and y values
stmt.setFloat(1, x);
stmt.setFloat(2, y);
stmt.executeUpdate();

Note you can use ST_MakePoint as an easier version of concatenating text values than using ST_PointFromText.

And, to answer the original question, the type should be geometry, though you can make this more explicit if you are only using a particular geometry type and you can also add a spatial reference ID (SRID), if you are working with one, which will act as a constraint on the column, eg,

CREATE table sometable (id serial, geom geometry(POINT, 4326));

will only allow you to insert points and in lat/lon. You can also set this to POLYGON , MUTLIPOLYGON , LINESTRING , etc. If you want to be more lax, you can just do,

 CREATE table sometable (id serial, geom geometry);

Yet another alternative is to use AddGeometryColumn which, again, allows to to explicitly state the geometry type and SRID, and also adds to the meta data view geometry_columns.