Sankar wrote:
> Hi,
> I am new to Database..I donot want insertion order of rows or
> records.. I need insertion order of tables..
>
> Consider if i am migrating from sourceDB to targetDB..through
> programatically
>
> First i will create DB and all tables in the targetDB..
>
> Then I have to move all the datas from sourceDB to targetDB... Here
> for moving i need insertion order of tables(to take care of forign key
> violations .. parent tables first thn child tables)
>
> regards
> Sankar R
>
> On Apr 2, 2:08 am, Roedy Green <see_webs...@[EMAIL PROTECTED]
>
> wrote:
>> On Tue, 01 Apr 2008 13:44:50 GMT, Roedy Green
>> <see_webs...@[EMAIL PROTECTED]
> wrote, quoted or indirectly quoted
>> someone who said :
>>
>>> What is "insertion" order?
>> In SQL, if the order rows are inserted in im****tant, you must add a
>> field to the record that you increment on each insertion or mark with
>> a timestamp. Then of course you use a perfectly ordinary ORDER BY on
>> the field to retrieve in that order.
>>
>> The autoincrement functions should be much faster than ones you
>> implement longhand. Back in the olden days of Codasyl databases, I
>> discovered incrementing these counters was what took the majority of
>> database activity.
>> --
>>
>> Roedy Green Canadian Mind Products
>> The Java Glossaryhttp://mindprod.com
>
You are going at it in the wrong way. You should do this as:
1) Create all new tables without foreign-key constraints
2) Copy all data from the source to the new tables
3) Create the referential constraints
This process is independent of table ordering.
It is not generally possible to define a table ordering where checks and
referential constraints will always be satisfied during table-by-table
insertions. If you can do that for your particular database (you seem to
because you create the new tables in some specified order) then simply
remember the order in which you created them so you can populate the
tables in the same order.
Regards,
Silvio
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