Altering Google AppEngine Datastore Table While Preserving Data -


i using python developing google app engine application. question while in development several times need modify data models adding, deleting or changing data type of fields. modifying models doesn't take effect until use clear_datastore destroys data. true or doing thing wrong ?

the datastore schema-less; means can have entities of same kind different properties. changes do take effect, existing data not automatically updated new schema. under covers entities protocol buffers, dict (key-value pairs).

when want make changes schema and have existing data needs updated too, you'll need convert in way. often, need write special script load original entity, convert new schema, re-put it. google has article discussing topic.


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