3
我正嘗試創建(類似)發票號碼生成器。但是,由於發票創業時可能爲零或更多,因此您如何知道某個實體是否存在?檢查數據存儲中的實體是否存在於GAE Python
query = "SELECT loanNumber FROM Loans ORDER BY loanNumber DESC LIMIT 1"
loanNumbers = db.GqlQuery(query)
result = loanNumbers.get()
# for loanNumber in loanNumbers:
if loanNumbers is None:
print "Print the first number"
else:
print "Print the next number"
錯誤
KindError: No implementation for kind 'Loans'