MB_ is the reference (name) assigned to the records returned by the query encased in parenthesis directly preceding it. You can think of it as a variable that can be referenced (It is referenced before it is "set" when the code says "Select MB_.GDB_ARCHIVE_OID
From"). In this case you are selecting the GDB_ARCHIVE_OID field from the result set of the query:
(SELECT GDB_ARCHIVE_OID,
ROW_NUMBER() OVER (PARTITION BY OBJECTID
ORDER BY gdb_from_date DESC) rn, gdb_is_delete
FROM Buildings
WHERE (gdb_branch_id = 0 AND
gdb_from_date <= '12.31.9999 23:59:59.000'))
Partition is to complicated to go into here, but its used to perform calculations on subsets. Here's a link:https://www.sqlshack.com/sql-partition-by-clause-overview/
DESC just tells the query (subquery in this case) to order the returned records in descending order
"rn" and 'gdb_is_delete" are fields returned by the query being referenced by MB_
Looks like this query is getting all existing (non-deleted) buildings from a FC base table name "Buildings" in the Default version (gdb_branch_id = 0); and its using three select statements to do it...
To me its some pretty heady stuff, but might point me to the answer to a question I have, which is how to I pull a reference to just my existing features from a branch versioned (BV) database. Sort of an "versioned view" for BV... Can you share where you found the SQL code?
