大约有 44,000 项符合查询结果（耗时：0.0302秒） [XML]
Measure the time it takes to execute a t-sql query
... to just grab the current date and time.
In SQL Server Management Studio
SELECT GETDATE();
SELECT /* query one */ 1 ;
SELECT GETDATE();
SELECT /* query two */ 2 ;
SELECT GETDATE();
To calculate elapsed times, you could grab those date values into variables, and use the DATEDIFF function:
DECL...
Get records with max value for each group of grouped SQL results
...
There's a super-simple way to do this in mysql:
select *
from (select * from mytable order by `Group`, age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first row. T...
What are some uses of template template parameters?
....2, 3.3, 4.4 };
std::cout << vf << '\n';
std::list<char> lc { 'a', 'b', 'c', 'd' };
std::cout << lc << '\n';
std::deque<int> di { 1, 2, 3, 4 };
std::cout << di << '\n';
return 0;
}
Output
std::ostream &operator<<...
Encrypt & Decrypt using PyCrypto AES 256
...code's scope - hashing is just a guarantee that the key is usable with the selected cipher.
– zwer
Jun 20 '17 at 20:35
2
...
Add a column to a table, if it does not already exist
...onstruct by using the sys.columns table io sys.objects.
IF NOT EXISTS (
SELECT *
FROM sys.columns
WHERE object_id = OBJECT_ID(N'[dbo].[Person]')
AND name = 'ColumnName'
)
share
|
...
SQL statement to get column type
...
Using SQL Server:
SELECT DATA_TYPE
FROM INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME = 'yourTableName' AND
COLUMN_NAME = 'yourColumnName'
share
|...
SQL Server loop - how do I loop through a set of records
how do I loop through a set of records from a select?
8 Answers
8
...
Why shouldn't I use mysql_* functions in PHP?
... 5.5 and above)
$link = mysql_connect('localhost', 'user', 'pass');
mysql_select_db('testdb', $link);
mysql_set_charset('UTF-8', $link);
With PDO: All you need to do is create a new PDO object. The constructor accepts parameters for specifying the database source PDO's constructor mostly takes fo...
What is meant by immutable?
...omething like this:
// Assume string is stored like this:
struct String { char* characters; unsigned int length; };
// Passing pointers because Java is pass-by-reference
struct String* substring(struct String* in, unsigned int begin, unsigned int end)
{
struct String* out = malloc(sizeof(struc...
Remove HTML tags from a String
...fortunately it also shrinks many spaces to one and removes link breaks (\n characters)
– Ridcully
Jul 31 '10 at 9:57
7
...