selecting from row id Options

[rokyj055]

Hi All,

I just want to know that "is it safe to select a columns using ROWID in a table?"

thanks in advance

[burleson]

>> "is it safe to select a columns using ROWID in a table?"


Safe? Define safe?


ROWID's can change, but you can use them in queries in some cases.

[rokyj055]

>> "is it safe to select a columns using ROWID in a table?"


Safe? Define safe?


ROWID's can change, but you can use them in queries in some cases.

Sir ,
Actually i wanted to select last 100 rows from a table.

desc t1
name varchar2(50)
address varchar2(50)

if this table table contained inter values then i cluld do it , but since it contains varchar datatype i did like following :

1.select rowid,name,address from t1;

<i got all row ids along with their name and address>
<then i found that 100th rowid starts from botton(last) of that table
suppose that 100th rowid from last is "asdfgha"
<and also i found last rowid of that table>
suppose that last rowid is "asdfghz"
<then i fired>
select rowid,name,address from t1 where rowid between 'asdfgha' and 'asdfghz' ;

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But i think this not a good way to query like this ......

what if have crores of values in a table

..........

[burleson]

PLease read:

http://www.dba-oracle.com/t_select_last_100_rows.htm

>> select last 100 rows from a table.

Oracle does not store rows "first" or "last"!

The concept of a "Last Row " is only valid if we implement some type of ordering mechanism for the rowset (a key value).

ROWNUM is a psuedo-column, what you are doing will not always work!

A more permanent solution is to add a date-time column to the table. Then it makes sense to have a "last 100" rows, by time.