I have a bunch of questions and am hoping someone could help clarify:

Triggers
 a.. OLDROW & NEWROW. Which does what? I'm pretty sure I already found =
out I can access newrow fields during inserts. That was pretty clear to =
me. What about with update & delete triggers?
 b.. I'm not sure how trigger conditions work, or what the syntax might =
be.=20
 c.. Are just the table records visible to trigger conditions or can I =
get to the oldrow/newrow fields too?
 d.. Can triggers be disabled? If not, is there something like a END, =
BREAK, ABORT keyword that would exit the trigger and have the underlying =
data updates still take effect (raising exceptions won't work cuz it'll =
bubble to the calling object). I'm thinking that might be helpful with =
troubleshooting along the way if a trigger looks suspect as a root cause =

 e.. If I have multiple after update triggers as an example, is there =
any particular order to how they fire?=20
 f.. Are there any plans for an "instead of" trigger type?
Security
 a.. If I grant a group execute permissions on a stored proc that =
modifies records, they also need matching table permissions to make the =
changes correct? Or does security drill down where "I'm allowed to =
execute this stored proc that changes data on TableX, so I am therefore =
allowed to make these edits on TableX". Kinda of like permission =
chaining with MS SQL perhaps?
 b.. I'm not even close to trying to reproduce my schema yet. Is there =
a relatively fast way for me to create a security group, grab an object =
type (say tables) and slap the right permissions on it in a loop =
fashion? Maybe a collection of objects?

Tables
 a.. What does a "check" constraint do? Might someone have an example =
of how it was applied or of a practical application for it? I can't find =
much in the help file for them
General
 a.. Does the "refresh" button refresh the entire explorer or just the =
branch highlighted?
 b.. What should I do (if anything) to release resources on the server =
to clean up stored procs etc? I've tried unpreparing but it flushed my =
data being returned, so I know that's not the right way. I've not been =
doing anything to release resources (like nulling variables for a =
cleanup etc with stored procs)
 c.. I've installed multiple versions of EDB so far 2.02.b8->b11. I'm =
not seeing any sample apps with any of them. I've seen forum posts =
pointing to a subdir in the installation path, but none of mine have it. =
Is there a place that I can download them from?
 d.. What's a "store"? How do they work? Anyone have any real world =
examples to share? I imported 40+ tables from another DB's export as CSV =
files. They're being referenced in a store though I am not sure that I =
implemented it as it were intended.
 e.. I know the database gets locked when a transaction is started by =
default. When I tested it, I used my app to start a transaction, and =
left it on a stop statement. I added a new row to a table using EDB Mgr, =
and it sat there until I ended the transaction in my app. Does anyone =
know if that's a normal behavior that I should see, or is the "wait til =
available" EDB Mgr demonstrated is specific to that app? My CPU wasn't =
fluttering at all, so it didn't look like a constant retry or a periodic =
retry sort of thing either.
Thanks for any feedback. It is appreciated.


jr

James,

Here are some answers to the triggers part:

> _Triggers_
>
>     * OLDROW & NEWROW. Which does what? I'm pretty sure I already found
>       out I can access newrow fields during inserts. That was pretty
>       clear to me. What about with update & delete triggers?

OLDROW and NEWROW are special row identifiers, that can be accessed from inside
trigers, that reference respectively the current and the new values of the row
being changed. The individual column values can be referenced using dot
notation, for example: NEWROW.Name references the new value for the name column.
The following table shows the various possibilities where OLDROW and NEWROW can
occour :

Type of Trigger                OLDROW                NEWROW
--------------------+-------------------------+------------------------
BEFORE/ERROR INSERT | (*)                     | Values to insert
AFTER INSERT ...... | (*)                     | Inserted values (R)
BEFORE/ERROR UPDATE | Values before update (R)| Values after update
AFTER UPDATE        | Values before update (R)| Values after update (R)
BEFORE/ERROR DELETE | Values before delete (R)| (*)
AFTER DELETE        | Values before delete (R)| (*)
--------------------+-------------------------+------------------------

(*) The identifiers doesn't exist in this context.
(R) The identifier is read-only in this context.


>     * I'm not sure how trigger conditions work, or what the syntax might
>       be.

Trigger conditions are boolean sql expressions, so the syntax is the syntax of
sql boolean expressions, except for one detail: Trigger conditions can't
reference columns of other tables.
If the expression evaluates to false at the moment the trigger fires, no code
will be executed, just as if the trigger didn't fire.


>     * Are just the table records visible to trigger conditions or can I
>       get to the oldrow/newrow fields too?

You can use OLDROW and NEWROW in a trigger conditions as long as they exist in
the context of that trigger type. In fact, it's the only way to reference a
column inside a trigger condition.

>     * Can triggers be disabled? If not, is there something like a END,
>       BREAK, ABORT keyword that would exit the trigger and have the
>       underlying data updates still take effect (raising exceptions
>       won't work cuz it'll bubble to the calling object). I'm
>       thinking that might be helpful with troubleshooting along the
>       way if a trigger looks suspect as a root cause

As far as I know, they can't be disabled.
Raising an exception will cancel the operation (insert, delete, etc.) and if I
understood correctly that exactly the opposite of what you want.

>     * If I have multiple after update triggers as an example, is there
>       any particular order to how they fire?

I really don't know.
You must wait for Tim's answer.

>     * Are there any plans for an "instead of" trigger type?

I think there are, but the only person that can confirm this is Tim.

--
Fernando Dias
[Team Elevate]

James,

Now, security :

> _Security_
>
>     * If I grant a group execute permissions on a stored proc that
>       modifies records, they also need matching table permissions to
>       make the changes correct? Or does security drill down where "I'm
>       allowed to execute this stored proc that changes data on TableX,
>       so I am therefore allowed to make these edits on TableX". Kinda of
>       like permission chaining with MS SQL perhaps?

No. Stored procedures are executed using the "System" user as the current user.
This is deliberately done this way in order to permit the procedure to access
resources that the executing user may not have access to.

>     * I'm not even close to trying to reproduce my schema yet. Is there
>       a relatively fast way for me to create a security group, grab an
>       object type (say tables) and slap the right permissions on it in a
>       loop fashion? Maybe a collection of objects?

No. You must set the permissions for each object.
However, some privileges are automatically set when you create the objects.
For example, when you create a table, full permissions are automatically granted
to the users "System" and "Administrator" and to the role "Administrators" and
the "Delete", "Insert", "Update" and "Select" privileges are automatically
granted to the role "Public".


--
Fernando Dias
[Team Elevate]

James,

> _Tables_
>
>     * What does a "check" constraint do? Might someone have an example
>       of how it was applied or of a practical application for it? I
>       can't find much in the help file for them

Check constraints allows the specification of rules that define if a row is
valid or not. They are defined when the table is created(or added altering the
table). For example:
-----------------------------------------
CREATE TABLE Tbl1 (
  Name VARCHAR(30) ,
  Age INTEGER CHECH( Age>=0 AND Age<200 ),
  Adress VARCHAR(30)
)
------------------------------------------
This check constraint forces the values of "Age" to be in the range 0..200.
The condition (Age>=0 AND Age<200) is automatically tested by EDB when a row is
altered or inserted and an exception is raised if the expression evaluates to
false.

This is called a "column constraint" because it was defined as part of the
column definition and is a syntactic shorthand for the "table constraint" shown
in the example below:
----------------------------------------------------
CREATE TABLE Tbl1 (
  Name VARCHAR(30) ,
  Age INTEGER,
  Adress VARCHAR(30),
  CONSTRAINT "Check_Age" CHECK( Age>=0 AND Age<200 )
)
----------------------------------------------------
EDB automatically rewrites all column check constraints as table check constraints.

--
Fernando Dias
[Team Elevate]

James,

> _General_
>
>     * Does the "refresh" button refresh the entire explorer or just the
>       branch highlighted?
I think it refreshes the selected sub-tree and all sub-trees whose root is at
the same level, but I'm not sure...

>     * What should I do (if anything) to release resources on the server
>       to clean up stored procs etc? I've tried unpreparing but it
>       flushed my data being returned, so I know that's not the right
>       way. I've not been doing anything to release resources (like
>       nulling variables for a cleanup etc with stored procs)
Nothing - it's all automatic.
However I think it is a good practice to close and/or unprepare the cursors that
are no longer in use, if they are defined WITHOUT RETURN, of course.

>     * I've installed multiple versions of EDB so far 2.02.b8->b11. I'm
>       not seeing any sample apps with any of them. I've seen forum posts
>       pointing to a subdir in the installation path, but none of mine
>       have it. Is there a place that I can download them from?

They are in the following directory:

C:\Program Files\ElevateDB VCL Client-Server\Version 2\Dev Studio (Delphi)
2006\examples

You must adjust the path according to the Delphi version you are using.


>     * What's a "store"? How do they work? Anyone have any real world
>       examples to share? I imported 40+ tables from another DB's export
>       as CSV files. They're being referenced in a store though I am not
>       sure that I implemented it as it were intended.

A "store" is simply a named storage area where files can be located, or if you
prefer, a "store" is an alias to a directory on the hard disk. A store can be
local or remote. If it is local, it "points" to a directory in the local hard
disk; if it is a remote store, it points to a local store in a remote server,
referenced by an IP or host name.
The statements BACKUP, RESTORE, IMPORT, EXPORT, SAVE UPDATES and LOAD UPDATES
use stores as the source or destination of the files they deal with. Files in a
store can also be manipulated using the statements COPY FILE, DELETE FILE and
RENAME FILE.


>     * I know the database gets locked when a transaction is started by
>       default. When I tested it, I used my app to start a transaction,
>       and left it on a stop statement. I added a new row to a table
>       using EDB Mgr, and it sat there until I ended the transaction in
>       my app. Does anyone know if that's a normal behavior that I should
>       see, or is the "wait til available" EDB Mgr demonstrated is
>       specific to that app? My CPU wasn't fluttering at all, so it
>       didn't look like a constant retry or a periodic retry sort of
>       thing either.

That's normal, and that's why transactions must be committed or rolledback as
soon as possible.
Also, it's not not simply "wait til available" - after a timeout period an
exception is raised and the insert/alter is aborted.

--
Fernando Dias
[Team Elevate]

James,

<< d.. Can triggers be disabled? If not, is there something like a END,
BREAK, ABORT keyword that would exit the trigger and have the underlying
data updates still take effect (raising exceptions won't work cuz it'll
bubble to the calling object). I'm thinking that might be helpful with
troubleshooting along the way if a trigger looks suspect as a root cause >>

You can't disable them right now, but that is on the list along with
specifying their order of execution.

<< f.. Are there any plans for an "instead of" trigger type? >>

Yes.

<<  a.. If I grant a group execute permissions on a stored proc that
modifies records, they also need matching table permissions to make the
changes correct? Or does security drill down where "I'm allowed to execute
this stored proc that changes data on TableX, so I am therefore allowed to
make these edits on TableX". Kinda of like permission chaining with MS SQL
perhaps? >>

As Fernando indicated, right now EDB executes procedures under the System
user, but we will be allowing you to specify which user to execute the
procedure as in an upcoming version.

<< b.. I'm not even close to trying to reproduce my schema yet. Is there a
relatively fast way for me to create a security group, grab an object type
(say tables) and slap the right permissions on it in a loop fashion? Maybe a
collection of objects? >>

Well, you can define a role and then set the permissions for it on various
objects, but you have to do so for each table or object that you want to
apply the permissions to.

<< a.. Does the "refresh" button refresh the entire explorer or just the
branch highlighted? >>

It refreshes the current branch, including all sub-branches that are open.

<< b.. What should I do (if anything) to release resources on the server to
clean up stored procs etc? I've tried unpreparing but it flushed my data
being returned, so I know that's not the right way. I've not been doing
anything to release resources (like nulling variables for a cleanup etc with
stored procs) >>

They don't take up that much in terms of resources, so just leave them alone
and they will get cleaned up automatically when you dispose of the
EDBCommand, etc. that called them.

<< c.. I've installed multiple versions of EDB so far 2.02.b8->b11. I'm not
seeing any sample apps with any of them. I've seen forum posts pointing to a
subdir in the installation path, but none of mine have it. Is there a place
that I can download them from? >>

The DAC products don't have any samples yet.  The main reason for this is
that, like with ODBC, the .NET Data Provider architecture is pretty
standardized, with the differences for each provider falling into the
SQL/engine features realm.  However, I'll be porting the CDCollector sample
application shortly that will give one a good idea of how to create an
application use the EDB .NET Data Provider.

<< d.. What's a "store"? How do they work? Anyone have any real world
examples to share? I imported 40+ tables from another DB's export as CSV
files. They're being referenced in a store though I am not sure that I
implemented it as it were intended. >>

You can read about stores here:

http://www.elevatesoft.com/manual?action=mantopic&id=edb2sql&category=0&topic=20

<< e.. I know the database gets locked when a transaction is started by
default. When I tested it, I used my app to start a transaction, and left it
on a stop statement. I added a new row to a table using EDB Mgr, and it sat
there until I ended the transaction in my app. Does anyone know if that's a
normal behavior that I should see, or is the "wait til available" EDB Mgr
demonstrated is specific to that app? My CPU wasn't fluttering at all, so it
didn't look like a constant retry or a periodic retry sort of thing either.
>>

Yes, that's the normal behavior.

--
Tim Young
Elevate Software
www.elevatesoft.com

Thank you Fernando & Tim. Your level of detail is most definitely
appreciated.


jr

> You can't disable them right now, but that is on the list along with=20
> specifying their order of execution.
>=20

Some of my triggers run some last minute validation checks before =
deleting any records. However, I need to override this when testing with =
mass deletes of rows (basically scrapping the validation checks).

It looks like if I put in a trigger condition of "false=3Dtrue", the =
trigger does not execute.=20

Please correct me if I'm missing something, but my thoughts are that =
leveraging an impossible "true" condition does just about the same as =
disabling a trigger, no?

Thanks


jr

James,

<< It looks like if I put in a trigger condition of "false=true", the
trigger does not execute.

Please correct me if I'm missing something, but my thoughts are that
leveraging an impossible "true" condition does just about the same as
disabling a trigger, no? >>

Yes, that would also do the trick.

--
Tim Young
Elevate Software
www.elevatesoft.com