PostGIS ST_Buffer a polyline?

Question

I am trying to run a buffer around a polyline (geography). My first attempt below (based on ST_Buffer documentation:

SELECT ST_Buffer(ST_Geomfromtext(i30.geog),10,'endcap=round join=round');

gives an error:

missing FROM-clause entry for table "i30"
ST_Geomfromtext(**^here**i30.geog)      

Answer 1

What's i30? If it's a table, you'll need something like:

SELECT ST_Buffer(geog,10,'endcap=round join=round') FROM i30;

and your result will have a buffered geography for each row in i30.