GQLQuery with_cursor not working

Question

wondering if anyone knows why using cursors with GQLQuery doesn't seem to be working properly.

I'm running the following.

query = "SELECT * FROM myTable WHERE accountId = 'agdwMnBtZXNochALEglTTkFjY291bnQYpQEM' and lastUpdated > DATETIME('0001-01-01 00:00:00') ORDER BY lastUpdated ASC LIMIT 100"

if lastCursor:    
    dataLookup = GqlQuery(query).with_cursor(lastCursor)
else
    dataLookup = GqlQuery(query)

//dataLookup.count() here returns some value like 350

for dataItem in dataLookup:    
  ... do processing ...

myCursor = dataLookup.cursor()

dataLookup2 = GqlQuery(query).with_cursor(myCursor)

//dataLookup2.count() now returns 0, even though previously it indicates many more batches can be returned

Thanks for all your help.

Answer 1

You should not use a LIMIT in your query, as that will only return the first 100 results, and I assume you want all of them, but process them in batches of 100 each time.

Here's what I would do (based on your example code):

query = GqlQuery("SELECT * FROM myTable WHERE accountId = 
  'agdwMnBtZXNochALEglTTkFjY291bnQYpQEM' and 
  lastUpdated > DATETIME('0001-01-01 00:00:00') ORDER BY lastUpdated ASC")

dataLookup = query.fetch(100) # get first 100 results

for dataItem in dataLookup:
  # do processing

myCursor = query.cursor() # returns last entry of previous fetch

if myCursor:
  # get next 100 results
  dataLookup2 = query.with_cursor(myCursor).fetch(100)