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SQLite table constraint - unique on multiple columns
...ges based on the table definition type (see the second table where 'Alice' now has id = 4; the first table is doing more of what I expect it to do, keep the PRIMARY KEY the same). Be aware of this effect.
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django: BooleanField, how to set the default value to true?
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If you're just using a vanilla form (not a ModelForm), you can set a Field initial value ( https://docs.djangoproject.com/en/2.2/ref/forms/fields/#django.forms.Field.initial ) like
class MyForm(forms.Form):
my_field = fo...
How does one create an InputStream from a String? [duplicate]
...tream(string.getBytes("UTF-8"));
Note the UTF-8 encoding. You should specify the character set that you want the bytes encoded into. It's common to choose UTF-8 if you don't specifically need anything else. Otherwise if you select nothing you'll get the default encoding that can vary between syste...
How to check if all elements of a list matches a condition?
...a generator expression where appropriate):
>>> [x for x in items if x[2] == 0]
[[1, 2, 0], [1, 2, 0]]
If you want to check at least one element is 0, the better option is to use any() which is more readable:
>>> any(flag == 0 for (_, _, flag) in items)
True
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How to add title to subplots in Matplotlib?
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If you need to be able to specify the fontsize, use ax.set_title('title', fontsize=16) instead.
– Tobias P. G.
Jun 19 at 14:56
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Redis: Show database size/size for keys
...acticable for debugging to me, not too mention that the dump is a few gigs now!
– Bernhard Vallant
Oct 3 '11 at 23:47
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Django class-based view: How do I pass additional parameters to the as_view method?
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This method is now deprecated, now you can use url('<slug:slug>', MyView.as_view(), name='my_named_view')
– Rahat Zaman
Mar 7 '19 at 1:56
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Create an index on a huge MySQL production table without table locking
...ating MySQL's Schema without downtime
Thusfar, there's only one method I know of to update a MySql schema and not suffer an availability outage. Circular masters:
Master A has your MySQL database running on it
Bring Master B into service and have it replicate writes from Master A ( B is a slave ...
python-pandas and databases like mysql
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frame_query is now deprecated. Now use pd.read_sql(query, db) instead.
– Robert Smith
Apr 24 '15 at 22:43
add a com...
#1071 - Specified key was too long; max key length is 1000 bytes
...suming that the strings are all present; that is, that they are all there. If some are null, it will throw off your calculations and underreport short strings. You want to use count([field_name]) instead of count(*).
– D Mac
Jun 17 '18 at 18:59
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