SQL平均总是返回0

Question

I have a simple SQL command:

SELECT Avg('observations1') AS AvgFeedback,
       Avg('observations2') AS AvgChallenge,
       Avg('observations3') AS AvgTalk,
       Avg('observations4') AS AvgSkills,
       Avg('observations5') AS AvgExpectations
FROM   .observations
WHERE  obsschool = 'admin';  

However every result is 0 when there are numbers in each of the fields. What am I doing wrong? Thanks.

Answer 1

Remove the quotes ( ' ) wrapping your field names:

SELECT Avg(observations1) AS AvgFeedback,
       Avg(observations2) AS AvgChallenge,
       Avg(observations3) AS AvgTalk,
       Avg(observations4) AS AvgSkills,
       Avg(observations5) AS AvgExpectations
FROM   observations
WHERE  obsschool = 'admin'; 

When passing field names, no quotes necessary.

Answer 2

您可以尝试一下，看看会得到什么结果吗：

avg(cast(observations1 as dec(7,5))) as AvgFeedback