Hello Thang,
as far as I can see, what you are describing is a Nested Table Expression (NTE). This feature is an enhancement to SQL available on Datacom 15.1 via PTF
SO01886:
ENHANCEMENT DESCRIPTION:
This enhancement provides Nested Table Expressions (NTE). An NTE is a SELECT
that is written in the FROM clause in place of a table reference.
An NTE may contain an NTE, nested to any depth. However, at least initially,
an NTE may not contain a view.
Note that an NTE is "materialized" as a temporary table. (At a later date,
an NTE may be folded into the query for better performance.)
IMPORTANT NOTE: PTF SO01886 has been marked in error, so PTFs SO04015, SO05190 and SO08452 must be applied.
Please see "
Subselect" section of "
SELECT Statement" page on CA Datacom 15.1 documentation for full description.
Umberto
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Principal Support Engineer
Broadcom
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Original Message:
Sent: 08-04-2020 10:26 PM
From: THANG TRAN
Subject: Can Datacom process SQL commands with subquery in FROM clause?
Hello,
I don't know if CA Datacom accept SQL command with SUBquery in FROM clause, like in:
select * from (select columnName from Table) as tempTable
I try this and it doesn't work so it's likely that CA Datacom doesn't support nested queries or subqueries in From clause?