Placing register units on the map — Recipe (QGIS)
Tool-bound implementation of the Placing register units on the map (Task) Task Schema in QGIS 4.2. Worked example: Share of rented dwellings in Copenhagen (Example).
Data you need
| Role | Form | Level of measurement | Notes |
|---|---|---|---|
| Units | table without geometry | ids: nominal | each unit with an id pointing to its address and one to its building |
| Addresses | table | nominal ids | each address with the id of its entrance (house number) |
| Entrances (house numbers) | table | nominal ids | each with the id of its point |
| Entrance points | points, as WKT text or geometry | — | |
| Buildings (alternative route) | points, as WKT text or geometry | — | |
| Units on points (output) | points | the units’ fields | one point per unit |
Text files (CSV) are loaded with Layer › Add Layer › Add Delimited Text Layer…: tables with No geometry (attribute only table), point tables with Well known text (WKT), the geometry field, and the CRS.
Large national tables can be cut to the study area first with Extract by expression (Tool - QGIS) on a municipality field.
Select the units (Task Schema step 2)
Extract by expression (Tool - QGIS) on the unit table with the population’s conditions.
Join to the address point (steps 4–5)
Join attributes by field value (Tool - QGIS), with Join type one-to-one:
- Units ← addresses: Table field the unit’s address id, Table field 2 the address’s id; copy the address text and the entrance id.
- Result ← entrances: Table field the entrance id, Table field 2 the entrance’s id; copy the entrance text and the point id.
- Points ← units: Input layer the point table, Table field its id, Input layer 2 the joined units, Table field 2 the point id, Join type one-to-many, Discard records which could not be joined ticked. The point layer must be the input, because the output takes its geometry; one-to-many gives one point for each unit at the same entrance.
Or join to the building point
One join: Input layer the building points, Table field their id, Input layer 2 the units, Table field 2 the unit’s building id, one-to-many, discard unmatched.
Count (step 6)
Compare the number of units with the number of points, and save Unjoinable features from first layer to see which units found no address or building.
Checked in QGIS 4.2.2, October 2026.