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Summary:
What are the advantages and
disadvantages of using AE or SQR?
Answer
AE advantages:
AE can be called by Peoplecode from a page.
Built-in tools (meta-SQL) allow you to write SQL statements that
refer to "all the fields of this record" or "join all the keys
shared by these two tables." This is handy when record layouts
change; you don't have to edit every select or insert.
Built-in tools (temp tables) to run the same program many times
on separate portions of your data. Processing takes less clock
time.
Repeatability and restartability - this takes a special style of
programming. If you do all your processing in temp tables, not
only should your SQL run faster, but your output doesn't reach
your permanent tables until you're sure the program was
successful. So, if it abends, you don't have to worry about
half-updated tables. Using state records for your internal
variables aids debugging abends and restarting in mid-stream
after an abend.
You can write different versions of a section of code, and AE
will choose among them based on current date, type of database,
or market. This feature is obviously for developers at
Peoplesoft Corp to ship the same products worldwide, but it
could be useful for us.
Built-in debugger.
Easy communication with the process monitor using the message
catalog.
AE disadvantages:
Programming technique is very restrictive. Think of Peoplecode,
where you're only supposed to do certain things in FieldEdit and
other things in FieldChange. And it's easy to access fields in
the record of the Peoplecode, harder to access fields in other
records or rows of the buffer, still harder to access data
outside the buffer. AE can be worse.
You can only view one SQL statement or one block of Peoplecode
at a time. It's like programming or debugging through a
keyhole. And be careful printing your program - the print
routine leaves things out.
Because it's awkward to use global variables and tempting to use
meta-SQL, you'll want to do as much as possible in each SQL
statement. If you do, your SQL will get very complex, hard to
understand and maintain, and potentially buggy. We don't always
remember all the effects of a join - not only do we bring in
columns from other tables, but we also restrict our selection
and/or multiply our rows based on the matches (0, 1, or many)
from those other tables.
Awkward control structures make it hard to follow program logic.
SQR advantages:
Wonderful printing functions and barely adequate file I/O - both
absent from AE.
Easy to use internal variables and even arrays.
The option to choose our own editor, source control system,
etc. Control over the format of our code (AE editors tend to
rearrange things).
If SQR runs on the client or the command line, it can
communicate with the user in free form, including taking user
input.
SQR disadvantages:
No debugger.
A program must be completely within its source file. Include
files are merged in by the compiler. AE can call subroutines
within other programs.
Great similarities and small differences make it hard to switch
back and forth between Peoplecode and SQR.
*Questions excerpted from
ITToolBox.com*
Disclaimer: Contents are not reviewed for correctness and are not endorsed or
recommended by PeopleSoft-Planet.com. |
