how to group by, and select from two tables, need two records for each given id

Question

I am new to SQL query. Can you please help me with the following?

table 1 QuoteObservations:

id value quotePointId asOfTime 

table 2

Answer 1

I craeted this query, it works, but I bet there is a better and more efficient way to do it, can anyone out there help?

select q.*
from (
            select     QuoteObservations.id, QuoteObservations.value,   QuoteObservations.quotePointId, max(QuoteObservations.asOfTime) as asOfTime, QuoteObservations.dataProviderId, qp.quoteType
            from [QuoteObservations]
            inner join QuotePoints qp
            on qp.id = QuoteObservations.quotePointId
            where quotePointId = 1
            group by QuoteObservations.id, QuoteObservations.value, QuoteObservations.quotePointId, QuoteObservations.dataProviderId
    ) q
inner join (

            select     QuoteObservations.id, QuoteObservations.value, QuoteObservations.quotePointId, max(QuoteObservations.asOfTime) as asOfTime, QuoteObservations.dataProviderId, qp.quoteType
            from [QuoteObservations]
            inner join QuotePoints qp
            on qp.id = QuoteObservations.quotePointId
            where quotePointId = 2
            group by QuoteObservations.id, QuoteObservations.value, QuoteObservations.quotePointId, QuoteObservations.dataProviderId
) p
    on  q.id = p.id
inner join (
            select     QuoteObservations.id, QuoteObservations.value, QuoteObservations.quotePointId, max(QuoteObservations.asOfTime) as asOfTime, QuoteObservations.dataProviderId, qp.quoteType
            from [QuoteObservations]
            inner join QuotePoints qp
            on qp.id = QuoteObservations.quotePointId
            where quotePointId = 10
            group by QuoteObservations.id, QuoteObservations.value, QuoteObservations.quotePointId, QuoteObservations.dataProviderId
) s
    on  s.id = p.id

Answer 2

SELECT
    QuoteObservations.id, 
    QuoteObservations.value, 
    QuoteObservations.asOfTime,
    QuotePoints.quoteType
FROM
    QuoteObservations
    LEFT JOIN QuotePoints
    ON QuoteObservations.quotePointId = QuotePoints.id
WHERE
    QuotePoints.quoteType = 1 
    OR QuotePoints.quoteType = 2
ORDER BY 
    QuoteObservations.asOfTime DESC
LIMIT 1;

Answer 3

You need to remove the WHERE condition that is limiting the results on QuoteObservations.id =1 OR QuoteObservations.id = 2

Here is the revised SQL, with that condition removed. I have also moved the JOIN conditon into the JOIN clause.

SELECT  QuoteObservations.id, 
        QuoteObservations.value, 
        QuoteObservations.quotePointId,
        max(QuoteObservations.asOfTime) as asOfTime, 
        QuoteObservations.dataProviderId,
        QuotePoints.quoteType 
FROM    QuoteObservations
INNER JOIN
        QuotePoints 
ON      QuoteObservations.quotePointId = QuotePoints.id 
WHERE   QuotePoints.quoteType in (1,2)
group by 
        QuoteObservations.id, 
        QuoteObservations.value, 
        QuoteObservations.quotePointId,
        QuoteObservations.dataProviderId, 
        QuotePoints.quoteType;