Dynamic queries with knex-postgis - node.js

Question

I am building a simple API that also deal with geometries (store into postGIS).
I am using knex-postgis to access the ST_ spatial functions in postGIS with knex.
I have used this example to insert a point and it work when its hard coded.
But my lack of experience is leave me hanging, how can I make the query dynamic? I want to create a form with input for x and y value and send it to the ST_geomFromText function to save it to the geom type in the db.
Is this when you would use parameters? Could someone point me in the right direction?
// insert a point
const sql1 = db.insert({
id: 1,
geom: st.geomFromText('Point(0 0)', 4326)
}).into('points').toString();
console.log(sql1);
// insert into "points" ("geom", "id") values
(ST_geomFromText('Point(0 0)'), '1')
So far I have tried
router.post('/', (req, res, next) => {
queries.create(req.body).then(poi => {
res.json(poi[0]);
});
});
Insert query
create(poi) {
const sql = db.insert(poi).returning('*').into('poi');
return sql;
},
In Postman I am sending this in its body
{
"place": "test",
"comments": "new",
"numbers": 6,
"geom": "st.geomFromText('Point(-71.064544 44.28787)', 4326)"
}
But get an error "Unhandled rejection error: parse error - invalid geometry"
The hard coded object looks the same and is work fine.
I have a feeling that I am using the st.geomFromText wrong, but i dont I am not sure?
This is what i get if i console.log returned query
insert into "poi" ("comments", "geom", "numbers", "place") values ('new', 'st.geomFromText(''Point(-71.064544 44.28787)'', 4326)', 6, 'test')
(see how it does not change st.geom.. to st_geom..? Also the quotation marks around the ST function and the Point object is not right)
This string work when I run it in pgAdmin
insert into "poi" ("comments", "geom", "numbers", "place") values ('new', st_GeomFromText('Point(-71.064544 44.28787)', 4326), 6, 'test')
EDIT:
I console.log the hardcoded version too. It does no appear to add the extra '' on the geometry value
insert into "poi" ("geom") values (ST_geomFromText('Point(-71.064544 44.28787)', 4326))
Any advice?

Answer 1

You pass coordinates from postman as string value in JSON object
"geom": "st.geomFromText('Point(-71.064544 44.28787)', 4326)"
And expect your code to transform it into a function call
st.geomFromText('Point(-71.064544 44.28787)', 4326)
What knex does in this case. It takes your string and convert it as it is string field (here you get a single quote ' replacement with double '' for Postgres to escape it).
What you can do. Pass your geometry to your API like this
"geom": "Point(-71.064544 44.28787)"
And in your route handler
create(poi) {
const sql = db.insert({
place: poi.place,
comments: poi.comments,
numbers: poi.numbers,
geom: st.geomFromText(poi.geom, 4326)
}).returning('*').into('poi');
return sql;
},