On Monday, March 11, 2013 4:56:11 PM UTC-4, Arkilic, Arman wrote:
Hi,
I am working on a database design that I am required to use lots of tables
with one-to-many relationship. As a consequence of the design, I need to
insert thousands of entries. I tried session.add(), session.merge,
Thanks Russ - took a look and found it very interesting indeed.
Cheers
Warwick
On Monday, March 11, 2013 4:56:11 PM UTC-4, Arkilic, Arman wrote:
Hi,
I am working on a database design that I am required to use lots of tables
with one-to-many relationship. As a consequence of the design, I
Thank you, Michael! The only apparent difference was that HasOIDs was
set to TRUE on my table. On your notes:
1. Will do. I've been a exec for a decade and my coding skills/
ability to absorb technical reading has deteriorated severely. For
some reason mapper was easier for me to pick up.
So, I can use that way in inserting one row, but can't when inserting
multiple rows ? It is correct ?
2008/11/24 Michael Bayer [EMAIL PROTECTED]:
oh, right. Column objects only work when you say insert().values(**dict).
MikeCo wrote:
Using 0.5.0rc4 doesn't seem to do that. or what am I
Petr Kobalíèek wrote:
So, I can use that way in inserting one row, but can't when inserting
multiple rows ? It is correct ?
you can only use string keys as the arguments to the execute() method.
this applies to one row or many. columns as keys can be used for the
values argument/generative
You probably don't want to do the inserts one by one because of the
commit overhead, or needing to rollback on failure of on insert. You
can still get multiple inserts in one transaction. Add this to the
example posted at http://pastebin.com/fd0653b0 to see three inserts in
one transaction.
Oops, I stand corrected. see http://pastebin.com/fe4a38d6
At least for SQLite, my loop solution is many times slower than the
insert many syntax. I would be curious to see results run against
different database engines. I don't have quick access to them right
now.
Still, unless there are very
executemany() syntax is very efficient and I dont really understand
how the column/string thing is that much of an issue other than an
small inconvenience and a slight failure of the API to be
consistent...all you have to do is convert the dict keys to be
column.key.
On Nov 26, 2008,
And that is what we did in our application before this discussion even
started. Don't know what Petr is doing in his.
I think it is more of an interesting, mostly academic, discussion
about alternative techniques; probably a very low priority issue to
the SA code base.
On Nov 26, 5:56 pm,
insert() has had some inconsistencies being reported as of late (like
params() ) that i would like to get nailed down. a construct like
this shouldn't have any surprises.
On Nov 26, 2008, at 6:04 PM, MikeCo wrote:
And that is what we did in our application before this discussion even
Oops, not quite right. str(table.c.colname) returns 'table.colname,
and that doesn't work right as dictionary key. You need col only as
dictionary key.
http://pastebin.com/fd0653b0 has some tests
Interesting question is does SA intend that table.colname work in
the dictionary definition?
--
the actual Column object or its key can be placed in the dict.
MikeCo wrote:
Oops, not quite right. str(table.c.colname) returns 'table.colname,
and that doesn't work right as dictionary key. You need col only as
dictionary key.
http://pastebin.com/fd0653b0 has some tests
Interesting
Using 0.5.0rc4 doesn't seem to do that. or what am I doing wrong?
The test, http://pastebin.com/fd0653b0 , looks like when using the
Column object, the values inserted are all None (test 1). When the key
is the fully qualified table.column, the value inserted is always
the default value for the
oh, right. Column objects only work when you say insert().values(**dict).
MikeCo wrote:
Using 0.5.0rc4 doesn't seem to do that. or what am I doing wrong?
The test, http://pastebin.com/fd0653b0 , looks like when using the
Column object, the values inserted are all None (test 1). When the
Your dictionary key CartItemTable.c.colname is an instance of class
Column, The dictionary keys need to be strings. Use str
(CartItemTable.c.colname) to get the string name of the column and it
should work.
CartItemTable.c.userId
Column('userId', Integer(), ForeignKey('User.userId'),
On May 21, 2008, at 5:06 PM, EricHolmberg wrote:
I'm doing a query and would like to order the results in alphabetical
order. However, the column used is mixed case, so the results have
all lower-case strings before the upper-case variables.
In SQL, I would fix this by using the lower()
# How do I apply the lower(field) function to the strName column?
rows = model.data.query().order_by(strName).all(
query.order_by(func.lower(strName))
Thanks Michael - you're a life saver! Somehow, I seemed to have
missed the entire section on sqlalchemy.sql.func.
For anybody else in the
the treenodes table has no explicit sorting field, so by default it
will sort by either the row ID of the table or the primary key field.
the only operation that can be issued to the database when you add an
item to the list is INSERT, so this will always assemble new nodes as
the last element in
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