dynamodb行数通过python，boto查询

问题描述

伙计们，
我试图获取下面的代码来返回表中的行数：

  import boto 
从boto.dynamodb2.table import boto.dynamodb2 
 import table 
从boto.dynamodb2.fields import HashKey，RangeKey 
 
 driver = Table（ 'current_fhv_drivers'）
 rowcountquery = drivers.query（
 number ='blah'，
 expiration ='foo'，
 count = True，
）
 for rowcountquery中的x：
 print x ['Count'] 
  

我看到的错误是：

  boto.dynamodb2.exceptions.UnknownFilterTypeError：无法识别 count中的运算符 count。 
  

获取行数的正确语法是什么：）

谢谢！

解决方案

该异常基本上是在告诉您boto无法识别运算符 count。 / p>

如果您阅读了您会看到：

所以我将代码更改为：

 导入boto 
导入boto.dynamodb2 
从boto.dynamodb2.table import表
从boto .dynamodb2.fields import HashKey，RangeKey 
 
 drivers = Table（'current_fhv_drivers'）
 rowcountquery = drivers.query（
 number__eq ='blah'，
 expiration__eq = 'foo'，
 count__eq = True，
）
 for rowcountquery中的x：
 print x ['Count'] 
  

Folks, Am trying to get the following bit of code working to return the row count in a table:

import boto
import boto.dynamodb2
from boto.dynamodb2.table import Table
from boto.dynamodb2.fields import HashKey, RangeKey

drivers = Table('current_fhv_drivers')
rowcountquery = drivers.query(
   number = 'blah',
   expiration = 'foo',
   count=True,
  )
for x in rowcountquery:
 print x['Count']

Error I see is:

boto.dynamodb2.exceptions.UnknownFilterTypeError: Operator 'count' from 'count' is not recognized.

Whats the correct syntaxt to get row count :)

Thanks!

解决方案

That exception is basically telling you that the operator 'count' is not recognized by boto.

If you read the second paragraph on http://boto.readthedocs.org/en/latest/dynamodb2_tut.html#querying you'll see that:

So I would change your code to:

import boto
import boto.dynamodb2
from boto.dynamodb2.table import Table
from boto.dynamodb2.fields import HashKey, RangeKey

drivers = Table('current_fhv_drivers')
rowcountquery = drivers.query(
   number__eq = 'blah',
   expiration__eq = 'foo',
   count__eq = True,
  )
for x in rowcountquery:
 print x['Count']

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