如何获取App引擎数据存储中的所有实体？ [英] How to fetch all entities in App engine datastore?

问题描述

在 http://code.google.com/appengine中/docs/python/datastore/entities.html#Saving_Getting_and_Deleting_Entities

获取实体的批处理操作如下所示：

批量获取。实体= db.get（[k1，k2，k3]）

如何在不提供键的情况下获取所有实体？

解决方案

我得到了一个解决方案，可以在
Datastore Queries - Query interface example ：

= new Query（Person）
PreparedQuery pq = datastore.prepare（q）;
for（实体结果：pq.asIterable（））{
String firstName =（String）result.getProperty（firstName）;
String lastName =（String）result.getProperty（lastName）;
Long height =（Long）result.getProperty（height）;
System.out.println（lastName ++ firstName +，+ height.toString（）+inches tall）;
}

我没有在查询中添加过滤器，因为它从数据存储返回所有实体。

in http://code.google.com/appengine/docs/python/datastore/entities.html#Saving_Getting_and_Deleting_Entities

the batch operation for getting the entity are stated below:

A batch get. entities = db.get([k1, k2, k3])

How can I fetch all entities without supplying keys?

解决方案

I got a solution on this and can be found in Datastore Queries - Query interface example:

Query q = new Query("Person") 
        PreparedQuery pq = datastore.prepare(q);  
    for (Entity result : pq.asIterable()) {   
       String firstName = (String) result.getProperty("firstName");   
       String lastName = (String) result.getProperty("lastName");   
       Long height = (Long) result.getProperty("height");   
       System.out.println(lastName + " " + firstName + ", " + height.toString() + "inches tall"); 
}

I did not add filter in query since it return all entities from datastore.

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