- I can easily perform SQL statement to lookup for some information such as, total employee, who are above 30 years old, and who has the Lastname of 'Smith'. - I can easily retrieve information from multiple tables and combine it as data objects.
But how can I do this in ZODB?
1) If your data set is not too big, you can do it programmatically Python: set = folder.objectValues() results = [] for elt in set: if (elt.age > 30) and (elt.lastname=='Smith'): results.append(elt) return elt One can easily replace '30' and 'Smith' with parameters to get a more useful script. 2) Use ZCatalog for this if you have larger sets to avoid unnecessary traversals. But I suspect the larger problem is that you're thinking tabularly. Trying to make a 1-to-1 translation between an object-storage scheme and a relational-storage scheme isn't always (or maybe usually) going to work. I know no magic processes for this, unfortunately. --jcc