Translate postgis data to a coordinate system [duplicate]

Question

I have a PostGIS database where the data is in an unknown or incorrect coordinate system. Is there a way given some known points in the data to translate all the data to a specific coordinate system.

Answer 1

I wrote a short blog post and some java code to solve this problem last week (and the pom to build it).

Answer 2

If it is just in an unknown co-ordinate system, but you know the EPSG code that is should be. You can run:

ST_SetSRID(geom,EPSG_code)

For example I have a table called lines, which has a geometry column called geom, which I want to set to EPSG:4326:

ALTER TABLE lines
ALTER geom TYPE geometry(LineString, 4326) USING ST_SetSRID(geom, 4326)