Re: What is wrong with Ada?

[Jason King <jhking@airmail.net>]

Generally in an Oracle database (this generalization based on about 15 
years experience in several industries) you find these datatypes employed.
VARCHAR2 - A string datatype that has the Oracle-specific behavior that 
trailing spaces are ignored in comparisons, eg
DECLARE
    x varchar2(10) := 'abc   ';
    y varchar2(10) := 'abc';
BEGIN
    IF x = y THEN
       dbms_output.put_line('They match');
    END IF;
END;
produces the output 'They match' on the console.  That, btw, is pl/sql 
but I'm sure the keywords and structure look familiar to everybody in c.l.a.
NUMBER(precision) -- integer
NUMBER(precision,scale) -- decimal number, Oracle stores these 
internally in a bcd-like manner so no floating-point rounding errors occur.
DATE -- actually date and time to seconds.
Recent versions of Oracle have added several flavors of
TIMESTAMP(precision) -- date and time to <precision> fraction of seconds
e.g.
DECLARE
    when timestamp(6); -- time to seconds/100000

In pl/sql code but not actually in the database itself you often see 
BOOLEAN which can have the values true, false and null, although 
booleans cannot be persisted as such into the database.

MSSQL has a currency datatype and several flavors of numeric datatypes, 
but as to how common their usage is I don't know because virtually all 
my real database work has been against Oracle.
For business applications I'd be surprised to see extensive use of REAL 
(esp if it maps to a c-style float or double) because of rounding 
issues.  The decimal item that business applications are most concerned 
about is generally money and rounding is fatal wrt money.
Recent versions of Oracle allow structured data in tables e.g.
create type address_t (   -- new object type
    address1 varchar2(50),
    address2 varchar2(50),
    city     varchar2(30),
    state    varchar2(3),
    zip      varchar2(9),
    country  varchar2(3)
    -- we could define methods as well as members
);
create table contacts (
    name varchar2(50),
    address address_t
);
Creates a table that contains an address as part of the datatype. 
Inside Oracle this is fairly straightforward to access, e.g.
BEGIN
    FOR c IN (SELECT * from CONTACTS ) LOOP
        -- iterate through contacts table
        dbms_output.put_line(c.address.state) ; -- print contact's state
   END LOOP;
END;
Accessing the object from non-Oracle tools like Crystal Reports is often 
more difficult.
Georg Bauhaus wrote:
> On Thu, 2007-04-12 at 21:59 -0500, Jason King wrote:
>>  Work with us pl/sql people and you 
>> might find large sets of database developers using Ada as a middleware 
>> or front-end tool.
> 
> Would Cobol style records be relevant in current database
> programming? I'm asking because of Annex F, Information Systems
> combined with the elaborate base types of Ada always seemed to be
> a good match for an RDBMS that uses more than INT, REAL,
> and CHARACTER VARYING. (Is anyone in the wild actually using
> a money type or a decimal type in table definitions?)
> 
>