大约有 47,000 项符合查询结果（耗时：0.0463秒） [XML]
PostgreSQL delete all content
...har(30),
constraint pk_customer primary key (customer_id)
);
create table orders (
order_id int not null,
number int not null,
customer_id int not null,
constraint pk_order primary key (order_id),
constraint fk_customer foreign key (customer_id) references customers(customer_id)
);
create table lo...
Remove all the elements that occur in one list from another
...- set([2,3,5,8])
set([1, 6])
Note, however, that sets do not preserve the order of elements, and cause any duplicated elements to be removed. The elements also need to be hashable. If these restrictions are tolerable, this may often be the simplest and highest performance option.
...
How to drop all tables in a SQL Server database?
...
Doesn't consider FKs/order.
– Josh
Mar 28 '16 at 17:37
1
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Sorting object property by values
...nce you have the array, you could rebuild the object from the array in the order you like, thus achieving exactly what you set out to do. That would work in all the browsers I know of, but it would be dependent on an implementation quirk, and could break at any time. You should never make assumption...
List comprehension: Returning two (or more) items for each item
...I used to find them a little confusing because I kept trying to invert the order.
– DSM
Aug 8 '12 at 17:07
1
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Why should a function have only one exit-point? [closed]
....
This became especially true when you needed to interject assignments in order to examine state (replaced with watch expressions in modern debuggers). It was also too easy to alter the control flow in ways that hid the problem or broke the execution altogether.
Single-exit methods were easier to ...
How do I use a PriorityQueue?
...d pass in a comparator which compares in the appropriate way for your sort order. If you give an example of how you want to sort, we can provide some sample code to implement the comparator if you're not sure. (It's pretty straightforward though.)
As has been said elsewhere: offer and add are just d...
Why the switch statement cannot be applied on strings?
...array but it doesn't really fully understand the notion of a string.
In order to generate the code for a switch statement the compiler must understand what it means for two values to be equal. For items like ints and enums, this is a trivial bit comparison. But how should the compiler compare 2...
Correct idiom for managing multiple chained resources in try-with-resources block?
...r comments: simplest is (2) to use Closeable resources and declare them in order in the try-with-resources clause. If you only have AutoCloseable, you can wrap them in another (nested) class that just checks that close is only called once (Facade Pattern), e.g. by having private bool isClosed;. In p...
SqlException from Entity Framework - New transaction is not allowed because there are other threads
...ds, you can write your query like this:
foreach (var client in clientList.OrderBy(c => c.Id).QueryInChunksOf(100))
{
// do stuff
context.SaveChanges();
}
The queryable object you call this method on must be ordered. This is because Entity Framework only supports IQueryable<T>.Sk...