Re: Trigger Code

"Redd" <javatek?@usa.com> wrote:

>
>
>--
>javatek?@usa.com
>
>remove the ? to reply.
>"Mark C. Stock" <mcstockX_at_Xenquery .com> wrote in message
>news:PfWdnc-muMypasHdRVn-gQ_at_comcast.com...
>> | Quantity Integer
>> | OldQuantity Integer
>> | OnOrder Char
>> |
>> |
>> | Does anyone know how to write the trigger that on update
>> | if Quantity is equal to or less than OldQuantity write the
>> | Character "T" to the OnOrder field.
>> |
>> |
>> |
>> |
>>
>> use a 'before update ... for each row' trigger with a 'when' condition
>that
>> compares the oldquantity and new quantity, and assign the value 'T' to
>> onorder
>What I would like is to see what that actual code segment would look like.
>We are going to use this as a small test to see if any of the DBAs to be
>interviewed can write triggers. I am not a programmer.
>
>

It's really a big mistake to have non-technical people evaluate technical skills, especially with a syntax driven question. I'm not a DBA (I'm a programmer), but I've written triggers for different databases, and with minimal effort can figure out how to do so for any database I may be asked to work with. It's not bragging, it's just not that hard.

Just in case you don't know what I mean by the phrase a "syntax driven question", I'll use Mark's sample trigger from his reply as an example.

• begin extract from Mark's message --- create or replace trigger sample_trigger before insert or update on t1 for each row when (new.quantity > old.quantity) begin :new.onorder := 'T'; end;
• end extract from Mark's message ---

One example of the "syntax" in this sample are the dot "." between the namespace and field name (eg. "new.quantity" and "old.quantity") [which, by the way, I think should be ":new.quantity" and ":old.quantity" instead]. Other examples of syntax are the single quotes around the character value ('T') to be changed and the semi-colons (;) which end the statements.

The syntax and other nuances of any particular environment (programming language, database, IDE, or other tool) are usually contained in the documentation, so many professionals don't memorize them. Rather, they are familiar with concepts that most environments support (eg. triggers for databases) and know how to quickly figure out (look up, RTFM) any environment specific details.

While syntax driven questions and other performance based interview techniques can be useful if you are looking for someone with specific experience (say, an Oracle DBA, but not other DBA flavors), I think you increase the risk of overlooking qualified applicants when non-technical people are the only ones evaluating technical skill.

Being ordinary and nothing special is a full-time job. jp_mcmahon_at_hotmail.com (Jim McMahon in real life) Received on Sun Mar 21 2004 - 07:07:03 CST