当查询包含来自多个数据库的表的连接时，如何在 boto3 中设置 QueryExecutionContext? [英] How to set QueryExecutionContext in boto3 when the query contains joining of tables from multiple databases?

问题描述

我在 python3 中使用 Boto3 包来执行 Athena 查询.来自 Boto3 的文档，我知道我可以指定查询执行上下文，即必须在其下执行查询的数据库名称.使用正确指定的查询执行上下文，我们可以从查询中省略完全限定的表名(db_name.table_name)，而只使用表名.

I am using Boto3 package in python3 to execute an Athena query. From the documentation of Boto3, I understand that I can specify a query execution context, i.e. a database name under which the query has to be executed. With a properly specified query execution context, we can omit the fully qualified table name(db_name.table_name) from the query and instead use just the table name.

因此查询 SELECT * FROM db1.tab1 可以转换为 SELECT * FROM tab1 使用 QueryExecutionContext : {'database':'db1'}

So the query SELECT * FROM db1.tab1 can be converted to SELECT * FROM tab1 with QueryExecutionContext : {'database':'db1'}

问题:我需要从 python 对 Athena 运行一个查询，它看起来像这样

The problem: I need to run a query on Athena from python which looks something like this

SELECT *
FROM   ((SELECT *
        FROM   db1.tab1 AS Temp1)
        INNER JOIN (SELECT *
                    FROM   db2.tab2 AS Temp2)
                ON temp1.id = temp2.id)  

如我们所见，查询连接了来自两个不同数据库的表.如果我想从这个查询中省略数据库名称，我该如何指定 QueryExecutionContext ?

As we can see, the query joins tables from two different databases. If I want to omit the database names from this query, how do I specify the QueryExecutionContext ?

推荐答案

QueryExecutionContext 只接受一个数据库作为参数.因此，如果您想跨多个数据库运行查询，则必须将完全限定的表名与数据库一起传递.

QueryExecutionContext accepts only one database as an argument.So if you want to run a query across multiple databases then you have to pass fully qualified table name along with database.

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