Hi, Vector Layer filtering SQL syntax is limited to the data provider. If you are using a shapefile, then the provider is GDAL and you are limited to this operands:
http://www.gdal.org/ogr_sql.html If you used Geopackage or Spatialite or PostGIS you would probably have more datetime specific operands that might work with your field. Alexandre Neto A sex, 20/10/2017, 03:30, Patrick Dunford <blackwhite...@gmail.com> escreveu: > I have a shapefile table with 300,000 records of polygons that I want > to filter for display on the map canvas. I want to use the field called > "date" which is defined as a Qdate in the fields list in the > shapefile's properties. > > The question is how to put in the filter string in the correct syntax > to give me for example all the records that are for the calendar year > of 1984. > > For example > year("date") = 1984 > will not work because it doesn't accept the year function from the list > of functions that are available in other expression editors which allow > a function list to be used. > > In a previous version of this table I had it was actually quite easy > because the dates were input as a string and the like operator could be > used. It seems with a date that is actually defined as a date field > there is no obvious or easy way to input a range of dates (how do you > put in a date constant) or use a function that will extract part of a > date from a date field. > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user -- Alexandre Neto --------------------- @AlexNetoGeo http://sigsemgrilhetas.wordpress.com http://gisunchained.wordpress.com
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