选择为问题

SELECT * 
FROM
    (
    SELECT
        t1.[user1], t1.[user2],(CAST(t1.[total_event_duration] AS DECIMAL))/(CAST (t2.[total_events_duration] AS DECIMAL)) AS buddy_strength 
        FROM [CDRs].[dbo].[aggregate_monthly_events] AS t1 
            INNER JOIN [CDRs].[dbo].[user_monthly_stats] AS t2 
                ON t1.[user1] = t2.[user1]  


   ) foo
        WHERE foo.buddy_strength > 0.02

不能在中使用别名 WHERE 条款。你需要重复整个表达( CAST(t1.[total_event_duration] AS DECIMAL))/(CAST (t2.[total_events_duration] AS DECIMAL)>0.02 ).

where , group by ,或 having 条款。可以通过将其包装在子查询中来解决此问题:

SELECT * FROM (
    SELECT
        t1.[user1],
        t1.[user2],
        (CAST(t1.[total_event_duration] AS DECIMAL))
            / (CAST (t2.[total_events_duration] AS DECIMAL))
            AS buddy_strength
    FROM [CDRs].[dbo].[aggregate_monthly_events] AS t1
    INNER JOIN [CDRs].[dbo].[user_monthly_stats] AS t2 ON t1.[user1] = t2.[user1]
) a
WHERE a.buddy_strength > 0.02

不能在where子句中使用别名列。我认为您必须在where子句中重新生成派生字段的值,如下所示:

SELECT t1.[user1], t1.[user2],(CAST(t1.[total_event_duration] AS DECIMAL))/(CAST (t2.[total_events_duration] AS DECIMAL)) AS buddy_strength 
    FROM [CDRs].[dbo].[aggregate_monthly_events] AS t1 
        INNER JOIN [CDRs].[dbo].[user_monthly_stats] AS t2 
            ON t1.[user1] = t2.[user1]  
    WHERE (CAST(t1.[total_event_duration] AS DECIMAL))/(CAST (t2.[total_events_duration] AS DECIMAL)) > 0.02