I have the parcels of a municipality, with a conformation of cadastral key in the following form:
Department, Town, Sector, property. Such that the nomenclature is composed as shown in the image: Example: 0313-0508-00059
The situation is that I am interested in being able to thematize the parcels based on the second chain, which is where the sector is formed (0508). So, that could have the lands with different color, depending on the sector that is identified in its cadastral key.
Sure there are ways to make it more advanced, but in this case, simply explain the principle using thematization from rules.
Right mouse button is done on the layer to be themed, Properties is chosen. Then in style, "Rule Based" is selected
Here a new rule is created using the constructor string expressions, I select from fields and values, the CLAVECATASTRAL field, indicating that see me:
All those where the string includes the cadastral key until the 0508 (0313-0508-)
So the string is «CLAVECATASTRAL» like '0313-0508-%' The symbol% is so that from then on the content does not matter.
I define as many rules as I want sectors. As you can see, it is no longer necessary to build them as the first, but only to make copy / paste to the query and modify the sector field. For each of them a fill color is defined, as shown in the following image.
And as a result, we have the map of plots based on the field tematizadas sector (Zone or map as you call this criterion district).
The style can be saved for your application at any time.