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How do I make many-to-many field optional in Django?
...ManyToMany relation without making it required just use blank=True:
class Group(models.Model):
...
events = models.ManyToManyField(Event, blank=True)
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PostgreSQL DISTINCT ON with different ORDER BY
...result sorted by purchased_at then you're trying to solve a greatest N per group problem which can be solved by the following approaches:
The general solution that should work in most DBMSs:
SELECT t1.* FROM purchases t1
JOIN (
SELECT address_id, max(purchased_at) max_purchased_at
FROM pur...
resizes wrong; appears to have unremovable `min-width: min-content`
...the following values:
table-cell (recommended)
table-column
table-column-group
table-footer-group
table-header-group
table-row
table-row-group
Of these, I recommend table-cell. Both table-row and table-row-group prevent you from changing width, while table-column and table-column-group prevent y...
How do I quickly rename a MySQL database (change schema name)?
...(I originally suggested the former and someone "improved" my answer to use GROUP_CONCAT. Take your pick, but I prefer the original):
SELECT CONCAT('RENAME TABLE $1.', table_name, ' TO $2.', table_name, '; ')
FROM information_schema.TABLES
WHERE table_schema='$1';
or
SELECT GROUP_CONCAT('RENAME ...
Are std::vector elements guaranteed to be contiguous?
... What about vectors of vectors? İnner vectors are right after last group's inner vectors?
– huseyin tugrul buyukisik
Apr 4 '16 at 20:04
1
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Text size and different android screen sizes
... width),
rather than trying to make your layout fit the generalized size groups
(such as large or xlarge).
The reason designing for 7" tablets is tricky when using the
generalized size groups is that a 7" tablet is technically in the same
group as a 5" handset (the large group). While t...
Python argparse: Make at least one argument required
...rbid more than one (XOR) is like this:
parser = argparse.ArgumentParser()
group = parser.add_mutually_exclusive_group(required=True)
group.add_argument('-process', action='store_true')
group.add_argument('-upload', action='store_true')
args = parser.parse_args()
print args
Output:
>opt.py ...
Delete all Duplicate Rows except for One in MySQL? [duplicate]
...es that could have duplicates repeated more than once you will also want a GROUP BY n1.id clause.
– usumoio
Oct 19 '13 at 0:00
...
Maven in Eclipse: step by step installation [closed]
...ncubating components) 1.5.0.20140606-0033 (org.eclipse.m2e.feature.feature.group 1.5.0.20140606-0033)
– Krunal Patel
Oct 6 '14 at 6:31
...
Scatterplot with marginal histograms in ggplot2
...
Is it possible to draw marginal density plots for objects grouped by color with this package?
– GegznaV
Mar 7 '16 at 15:29
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