Bug report #10066
layer from query - data type is not recognized when using operand in query
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Normal | ||
| Assignee: | - | ||
| Category: | DB Manager | ||
| Affected QGIS version: | 2.2.0 | Regression?: | No |
| Operating System: | Ubuntu | Easy fix?: | No |
| Pull Request or Patch supplied: | No | Resolution: | up/downstream |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 18542 |
Description
- connect to the attached db
- query in db manager:
select pkuid, text_col, int_col, 2 * int_col as twice_int, cast((2 * int_col) as real) as cast_twice_int, real_col, 2 * real_col as twice_real, cast((2 * real_col) as real) as cast_twice_real, geometry from pointlyr01
- add result from query as a layer in qgis
result: fields twice_int, cast_twice_int, twice_real, cast_twice_real are interpreted as text
expected result: these particular fields should be interpreted as double
If creating a table (see tab_fr_db_manager) by the exact same query and then adding the table to qgis, then the data types are double as expected for all relevant fields:
create table tab_fr_db_manager as select pkuid, text_col, int_col, 2 * int_col as twice_int, cast((2 * int_col) as real) as cast_twice_int, real_col, 2 * real_col as twice_real, cast((2 * real_col) as real) as cast_twice_real, geometry from pointlyr01;
SELECT RecoverGeometryColumn('tab_fr_db_manager', 'geometry', 4326, 'POINT', 'XY');
History
#1
Updated by Jürgen Fischer about 10 years ago
- Resolution set to up/downstream
- Status changed from Open to Closed
Apparently SQLite uses dynamic run-time typing and doesn't offer a way to retrieve the type of a column based on the query definition, but only on the individual values.