大约有 42,000 项符合查询结果（耗时：0.0238秒） [XML]
Kill a postgresql session/connection
...g the database.
def drop_database(config)
case config['adapter']
when /mysql/
ActiveRecord::Base.establish_connection(config)
ActiveRecord::Base.connection.drop_database config['database']
when /sqlite/
require 'pathname'
path = Pathname.new(config['database'])
file = path....
Interface type check with Typescript
...mentioned: since TypeScript 2.0, you can even take the advantage of tagged union type.
interface Foo {
type: 'foo';
fooProperty: string;
}
interface Bar {
type: 'bar';
barProperty: number;
}
let object: Foo | Bar;
// You will see errors if `strictNullChecks` is enabled.
if (objec...
How do I modify fields inside the new PostgreSQL JSON datatype?
...FROM json_each("json")
WHERE "key" <> "key_to_set"
UNION ALL
SELECT "key_to_set", to_json("value_to_set")) AS "fields"
$function$;
SQLFiddle
Edit:
A version, which sets multiple keys & values:
CREATE OR REPLACE FUNCTION "json_object_set_keys"(
"json" j...
how to exclude null values in array_agg like in string_agg using postgres?
...array[null]:
select
array_agg(x)-array['']
from
( select 'Y' x union all
select null union all
select 'N' union all
select ''
) x;
That's all:
{Y, N}
share
|
...
What is the fastest or most elegant way to compute a set difference using Javascript arrays?
...
Why JavaScript sets don't have union/intersect/difference built in is beyond me...
– SwiftsNamesake
Nov 27 '16 at 4:50
6
...
CMake使用教程 - C/C++ - 清泛网 - 专注C/C++及内核技术
...中找到这个手册对应的代码。
1、Step1。
（如果不知道如何使用cmake，以及如何使用编译产生的Turorial.exe，可先看下前面“CMake使用步骤”的说明，它以Step4为例详细介绍了使用过程，Step1的配置可能不够完全，比如无法运行make...
Difference between left join and right join in SQL Server [duplicate]
...i
Null Null Kathmandu
Full Join
Note : It is same as union operation, it will return all selected values from both tables.
Syntax:
SELECT column_name(s) FROM table1 FULL OUTER JOIN table2 ON table1.column_name = table2.column_name;
Apply it in your samp[le table:
SELECT...
Nginx serves .php files as downloads, instead of executing them
...ttps://www.digitalocean.com/community/tutorials/how-to-install-linux-nginx-mysql-php-lemp-stack-on-ubuntu-14-04 but when I try to run some .php file it's just downloading it...
for example... http://5.101.99.123/info.php it's working but... If I go to the main http://5.101.99.123 it's downloadi...
What is the difference between HashSet and List?
...ady existing in Set
Can perform mathematical set operations against a Set: Union/Intersection/IsSubsetOf etc.
HashSet doesn't implement IList only ICollection
You cannot use indices with a HashSet, only enumerators.
The main reason to use a HashSet would be if you are interested in performing Set ...
Where is C not a subset of C++? [closed]
...
In C++, if you declare a struct, union, or enum, its name is immediately accessible without any qualifiers:
struct foo { ... };
foo x; // declare variable
In C, this won't work, because types thus declared live in their own distinct namespaces. Thus, you ...