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Nullable Foreign Key bad practice?
Let's say you have a table Orders with a foreign key to a Customer Id. Now, suppose you want to add an Order without a Customer Id, (whether that should be possible is another question) you would have to make the foreign key NULL... Is that bad practice or would you rather work with a link table bet...
Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)
...use), not by record number. Discussions are
increasingly infinite-scroll ordered by date (again allowing index
use), not by paginated by post number. And so on.
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scanf() leaves the new line char in the buffer
...scanf terminology) other than conversions, like the literal text in scanf("order = %d", &order); doesn't skip whitespace either. The literal order has to match the next character to be read.
So you probably want " order = %d" there if you want to skip a newline from the previous line but still...
MongoDB Many-to-Many Association
...f clear then is generally discouraged, but if needed can be implemented by ordering the operations:
Get the list of user names from Role.users.
Iterate the user names from step 1, remove the role name from User.roles.
Clear the Role.users.
In the case of an issue, which is most likely to occur w...
Is there a way to 'uniq' by column?
...sort's manpage says: "-u, --unique with -c, check for strict ordering; without -c, output only the first of an equal run." So, it is indeed "the first occurrence of the duplicate before sorting."
– Geremia
Apr 15 '16 at 17:32
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How can I get the list of a columns in a table for a SQLite database?
...ft outer join pragma_table_info((m.name)) p
on m.name <> p.name
order by tableName, columnName
;
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Should I use encoding declaration in Python 3?
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@pepr A Byte Order Mark could do the same, no?
– endolith
Jul 3 '17 at 15:01
12
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How can I turn a List of Lists into a List in Java 8?
...a List<Object> that contains all the objects in the same iteration order by using the features of Java 8?
9 Answers...
How does `is_base_of` work?
...
It possibly has something to do with partial ordering w.r.t. overload resolution. D* is more specialized than B* in case D derives from B.
The exact details are rather complicated. You have to figure out the precedences of various overload resolution rules. Partial ord...
Single Line Nested For Loops
... the same as this nested for loop (and, as the tutorial says, note how the order of for and if are the same).
>>> combs = []
>>> for x in [1,2,3]:
... for y in [3,1,4]:
... if x != y:
... combs.append((x, y))
...
>>> combs
[(1, 3), (1, 4), (2, 3), ...