[英]SQL query in Google App Engine in Java?
I have to get all the entities in Google Datastore that fulfill a particular criteria 我必须获取Google数据存储区中满足特定条件的所有实体
I have 3 fields: 我有3个领域:
marks1, marks2, marks3
I want the entities that have marks greater than 60 in all the fields 我希望在所有字段中标记大于60的实体
but since datastore allows inequality operator on a single field. 但是由于数据存储区允许在单个字段上使用不等式运算符。
How can I bypass that.. Please suggest a solution that is not memory or processor intensive. 我该如何绕过呢。.请提出一种不占用大量内存或处理器的解决方案。
在您的实体中添加一个布尔属性allMarksGreaterThan60,并在每次标记之一更改时重新计算其值。
Alternatively, cou can now use Google Cloud Sql. 另外,cou现在可以使用Google Cloud Sql。 See https://developers.google.com/cloud-sql/docs/developers_guide_java for information on how to get up and running on Java. 有关如何在Java上启动和运行的信息,请参见https://developers.google.com/cloud-sql/docs/developers_guide_java 。 It's basically managed MySQL using standard jdbc to talk to App Engine. 它基本上是通过使用标准jdbc与App Engine进行对话来管理的MySQL。
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