I have a postcode centres table created from a shapefile and a census data table that is a CSV with postcodes. I need to add the census data columns to the postcode centres table. I would normally join them in QGIS based on the postcode and create the columns that way, but the files are too big and QGIS keeps crashing. So I've uploaded them into PostGIS and I am now trying to run a sql query on the data via the DB Manager plugin.
My data is in PostGIS accessed though QGIS 2.14. I'm very new to SQL.
INSERT INTO postcode_centres (total_pop, males_pop, females_pop, occupied_house_pop) (SELECT postcode_census.total, postcode_census.males, postcode_census.females, postcode_census.occupied_house FROM postcode_census WHERE postcode_centres.postcode = postcode_census.postcode);