Re: column name can't include character '-'

From: Mark C. Stock <mcstockX_at_Xenquery>
Date: Fri, 20 Feb 2004 06:22:04 -0500
Message-ID: <AN-dna1mUZuEc6jdRVn-vA_at_comcast.com>


"Mark D Powell" <Mark.Powell_at_eds.com> wrote in message news:2687bb95.0402191741.50904bbd_at_posting.google.com... | "Mark C. Stock" <mcstockX_at_Xenquery .com> wrote in message  news:<OLWdnaELQvHqVKndRVn-uA_at_comcast.com>...
| > | SQL> select a, b, a-b, "a-b" from marktest3;
| > |
| > | A B A-B a-b
| > | ---------- ---------- ---------- ----------
| > | 6 4 2 9
| > |
| > | SQL>
| > | SQL> drop table marktest3;
| > |
| > | Table dropped.
| > |
| > | If you need a col "a-b" it would be better to name it a_minus_b,
| > | diff_a_b, or some such than use double quotes to create potential
| > | problems for users.
| > |
| > | HTH -- Mark D Powell --
| >
| > unless there's a specific identified processing advantage to storing a
| > derived value, the "a-b" or a_minus_b column really should be
 implemented
| > via a view, not included in the table.
| > (function-based indexes would be an alternative if searches are often
 done
| > on the derived value, if an index would be effective in those searches)
| >
| > -- mcs

|
| Mark, very true.  I was just trying to make a point about meaningful
| names and should have thought of that also.
|
| Saving calculated values should only be done where either the
| variables of the calculation are not retained with the result such as
| in a history table OR the cost of calculating the result is too
| expensive.  Our electronics and prototype lab calculates values that
| often take significant time per calculation so even it the variable
| values are saved it is not feasible to recalculate the results for
| display.
|
| -- Mark D Powell --

point well made, and good real-world example

;-{ mcs Received on Fri Feb 20 2004 - 12:22:04 CET

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