问题
The sqlite database file properties.db is usually the biggest file in the output from https://extract.autodesk.io/.
What is it used for in Forge Viewer, and if it's not used, why is it available in the ZIP file?
回答1:
The reason this example is copying both is that the purpose of the sample is to demo how to extract the 'bubble' from the Autodesk server. The Design File' properties are extracted in 2 formats: aka json (json.gz) and sqlLite (sdb/db). The Autodesk Viewer only uses the json format, but other systems may prefer using sqlLite. The json approach makes it easier when you code executes in client browsers. It is fairly easier to modify the sample to exclude the sqlLite database if you are not interested to get this file. I can point you which code you need to modify if that's something you want to do.
回答2:
That file contains the components properties as a sqlite database, which are also contained in objects_xxx.json.gz. The viewer only uses the json format.
That article shows how you can easily run the extraction code your your side, it doesn't extract the .db file:
Forge SVF Extractor in Node.js
来源：https://stackoverflow.com/questions/46751920/how-properties-db-is-used-in-forge-viewer