大约有 45,000 项符合查询结果（耗时：0.0485秒） [XML]
Keeping it simple and how to do multiple CTE in a query
...s in one query, as well as reuse a CTE:
WITH cte1 AS
(
SELECT 1 AS id
),
cte2 AS
(
SELECT 2 AS id
)
SELECT *
FROM cte1
UNION ALL
SELECT *
FROM cte2
UNION ALL
SELECT *
FROM cte1
Note, however, that SQL Server may reevaluate t...
Correct way to pass multiple values for same parameter name in GET request
...s handle forms by default. For example take a look at the form element <select multiple> and how it handles multiple values from this example at w3schools.
<form action="/action_page.php">
<select name="cars" multiple>
<option value="volvo">Volvo</option>
<optio...
efficient way to implement paging
...inq (with SQL 2005 / 2008 as database server) your query will be using the Select ROW_NUMBER() Over ... statement, with is somehow direct paging in the SQL engine.
Giving you an example, I have a db table called mtcity and I wrote the following query (work as well with linq to entities):
using (Da...
How do shift operators work in Java? [duplicate]
...ts so that the value can be used as an index into the array of hexadecimal characters.
// Masking sign extension.
class HexByte {
static public void main(String args[]) {
char hex[] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
byte b ...
Where's my JSON data in my incoming Django request?
...'/event/save-json/',
type: 'POST',
contentType: 'application/json; charset=utf-8',
data: $.toJSON(myEvent),
dataType: 'text',
success: function(result) {
alert(result.Result);
}
});
Django:
def save_events_json(request):
if request.is_ajax():
if request...
Add … if string is too long PHP [duplicate]
...lay the whole field, but on the other, I just want to display the first 50 characters. If the string in the description field is less than 50 characters, then it won't show ... , but if it isn't, I will show ... after the first 50 characters.
...
Select distinct values from a table field
...tart with the fields in
distinct(), in the same order.
For example, SELECT DISTINCT ON (a) gives you the first row for each
value in column a. If you don’t specify an order, you’ll get some
arbitrary row.
If you want to e-g- extract a list of cities that you know shops in , the exam...
SQL - Query to get server's IP address
...
SELECT
CONNECTIONPROPERTY('net_transport') AS net_transport,
CONNECTIONPROPERTY('protocol_type') AS protocol_type,
CONNECTIONPROPERTY('auth_scheme') AS auth_scheme,
CONNECTIONPROPERTY('local_net_address') AS loc...
When should I use Struct vs. OpenStruct?
....new(:data1, :data2)
n = Newtype.new
C:
typedef struct {
int data1;
char data2;
} newtype;
newtype n;
The OpenStruct class can be compared to an anonymous struct declaration in C. It allows the programmer to create an instance of a complex type.
Ruby:
o = OpenStruct.new(data1: 0, data2:...
Why do pthreads’ condition variable functions require a mutex?
...pthread_cond_wait(&cond); //imagine cond_wait did not have a mutex
char *data = some_data;
some_data = NULL;
handle(data);
}
you'd naturally get a lot of race condition, what if the other thread did some_data = new_data right after you got woken up, but before you did data = some_d...