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Django select only rows with duplicate field values
...alues('name')
.annotate(Count('id'))
.order_by()
.filter(id__count__gt=1)
This is as close as you can get with Django. The problem is that this will return a ValuesQuerySet with only name and count. However, you can then use this to construct a regular...
Is there a unique Android device ID?
...on: android-developers.blogspot.com/2011/03/…
– emmby
Apr 7 '11 at 20:10
37
ANDROID_ID no longe...
SQL DROP TABLE foreign key constraint
... still the same 'Could not drop object 'my_table' because it is referenced by a FOREIGN KEY constraint.
– FrenkyB
Nov 16 '15 at 13:00
7
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What is the standard naming convention for html/css ids and classes?
...ning off, but it's interesting the compiler strongly suggests a convention by default. I imagine in larger projects it leads to cleaner code which is no bad thing.
Update 2016 (you asked for it)
I've adopted the BEM standard for my projects going forward. The class names end up being quite verbose...
How do SQL EXISTS statements work?
... WHERE o.supplier_id = s.supplier_id)
...should hit a division by zero error, but it won't. The WHERE clause is the most important piece of an EXISTS clause.
Also be aware that a JOIN is not a direct replacement for EXISTS, because there will be duplicate parent records if there's more...
What is the X-REQUEST-ID http header?
...
When you're operating a webservice that is accessed by clients, it might be difficult to correlate requests (that a client can see) with server logs (that the server can see).
The idea of the X-Request-ID is that a client can create some random ID and pass it to the server. T...
ssh “permissions are too open” error
...
Keys need to be only readable by you:
chmod 400 ~/.ssh/id_rsa
If Keys need to be read-writable by you:
chmod 600 ~/.ssh/id_rsa
600 appears to be fine as well (in fact better in most cases, because you don't need to change file permissions later to e...
Find the index of a dict within a list, by matching the dict's value
...ne)
# 1
If you need to fetch repeatedly from name, you should index them by name (using a dictionary), this way get operations would be O(1) time. An idea:
def build_dict(seq, key):
return dict((d[key], dict(d, index=index)) for (index, d) in enumerate(seq))
info_by_name = build_dict(lst, ke...
How to break a line of chained methods in Python?
...uery(Subkeyword.subkeyword_id, Subkeyword.subkeyword_word)
.filter_by(subkeyword_company_id=self.e_company_id)
.filter_by(subkeyword_word=subkeyword_word)
.filter_by(subkeyword_active=True)
.one()
)
...
How to concatenate strings of a string field in a PostgreSQL 'group by' query?
... am looking for a way to concatenate the strings of a field within a group by query. So for example, I have a table:
14 Ans...