Basic SQL mechanics, create table, then call that table from another script - sql

Question

I have two scripts that work in isolation, but I don't know how to stitch them together to do this all at once.
The first script:
SELECT *
FROM PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTES bq
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.PRODUCT p ON bq.ProductId = p.Id
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTEFEES F ON F.ApplicationQuoteId = bq.Id
LEFT JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.COVERAGESECTIONTYPE CST ON F.CoverageSectionTypeID = CST.SECTIONID
This produces a table (is that the right word?). Suppose I could save that table as 'appQuote'. I then want to run this script on it:
SELECT
ApplicationId,
STRING_AGG(YEARLYPAYAMOUNT) allPremium,
STRING_AGG(SECTIONID) allSection,
STRING_AGG(SHORTNAME) allSectionName,
FROM
appQuote
GROUP BY
ApplicationId
For storage reasons I don't want to actually save the table from the first script, I just want to get the result from the first script and immediately apply the second script to it.
This is very basic, so any guidance would help.

Answer 1

The relevant term is known as a derived table.
In SQL you can use the result of a query as the input to another. The "nested query" produces the derived table which is then consumed by the outer query:
Select <columns>
from (
select <columns> from table join table etc
)as TableAliasName

Answer 2

To get the nomenclature right, what you have are not scripts or tables, but rather two queries. When a query runs it produces a result set.
To accomplish your goal, either of these queries will work:
SELECT
ApplicationId,
STRING_AGG(YEARLYPAYAMOUNT) allPremium,
STRING_AGG(SECTIONID) allSection,
STRING_AGG(SHORTNAME) allSectionName,
FROM (
SELECT *
FROM PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTES bq
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.PRODUCT p ON bq.ProductId = p.Id
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTEFEES F ON F.ApplicationQuoteId = bq.Id
LEFT JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.COVERAGESECTIONTYPE CST ON F.CoverageSectionTypeID = CST.SECTIONID
) appQuote
GROUP BY
ApplicationId
Here, the inner nested query is formally called a derived table, but people will often use the phrase "subquery".
The other option is a Common Table Expression (CTE):
With appQuote As (
SELECT *
FROM PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTES bq
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.PRODUCT p ON bq.ProductId = p.Id
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTEFEES F ON F.ApplicationQuoteId = bq.Id
LEFT JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.COVERAGESECTIONTYPE CST ON F.CoverageSectionTypeID = CST.SECTIONID
)
SELECT
ApplicationId,
STRING_AGG(YEARLYPAYAMOUNT) allPremium,
STRING_AGG(SECTIONID) allSection,
STRING_AGG(SHORTNAME) allSectionName,
FROM
appQuote
GROUP BY
ApplicationId
Finally, you could also create a View from the first query:
CREATE View AppQuote As
SELECT *
FROM PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTES bq
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.PRODUCT p ON bq.ProductId = p.Id
JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.BCAPPLICATIONQUOTEFEES F ON F.ApplicationQuoteId = bq.Id
LEFT JOIN PROD_ANALYTIC.SRC_MVC_AU_DBO.COVERAGESECTIONTYPE CST ON F.CoverageSectionTypeID = CST.SECTIONID
A view is not just a query; it will actually become part of the database, such that you can use it in many of the same ways you would use a table saved on disk, and then the second query in the original question will run unmodified.