大约有 41,000 项符合查询结果（耗时：0.0230秒） [XML]
Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL
... to a date by suffixing it with ::date. Here, in psql, is a timestamp:
# select '2010-01-01 12:00:00'::timestamp;
timestamp
---------------------
2010-01-01 12:00:00
Now we'll cast it to a date:
wconrad=# select '2010-01-01 12:00:00'::timestamp::date;
date
------------
201...
How to use GROUP_CONCAT in a CONCAT in MySQL
...
select id, group_concat(`Name` separator ',') as `ColumnName`
from
(
select
id,
concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
...
Generate a random letter in Python
...tates If the relative weights or cumulative weights are not specified, the selections are made with equal probability. This would mean, that the distribution is the discrete uniform distribution (en.wikipedia.org/wiki/Discrete_uniform_distribution).
– Qaswed
Oc...
static const vs #define
...l than a post-preprocessing "if" as the code need not be compilable if not selected by the preprocessor), use #undef-ine, redefine etc.
substituted text has to be exposed:
in the translation unit it's used by, which means macros in libraries for client use must be in the header, so make and other ...
What is an unsigned char?
In C/C++, what an unsigned char is used for? How is it different from a regular char ?
17 Answers
...
Difference between signed / unsigned char [duplicate]
...gnify if the number if positive or negative, but how does this apply to a char ? How can a character be positive or negative?
...
How do I search an SQL Server database for a string?
...T)
INSERT INTO @Temp(TableName,SchemaName, ColumnName, DataType)
SELECT C.Table_Name,C.TABLE_SCHEMA, C.Column_Name, C.Data_Type
FROM Information_Schema.Columns AS C
INNER Join Information_Schema.Tables AS T
ON C.Table_Name = T.Table_Name
AND C.TA...
How to convert a std::string to const char* or char*?
How can I convert an std::string to a char* or a const char* ?
8 Answers
8
...
Check whether a path is valid
...ts
IEnumerable<string> allMachineDrivers = DriveInfo.GetDrives().Select(drive => drive.Name);
if (!allMachineDrivers.Contains(path.Substring(0, 3))) return false;
// Check if the rest of the path is valid
string InvalidFileNameChars = new string(Path.GetInvalidPathChars());...
tinyxml XML解析库下载（tinyxml2.h 和 tinyxml2.cpp） - 源码下载 - 清泛...
... Microsoft visual studio, version 2005 and higher.
/*int _snprintf_s(
char *buffer,
size_t sizeOfBuffer,
size_t count,
const char *format [,
argument] ...
);*/
inline int TIXML_SNPRINTF( char* buffer, size_t size, const char* format, ... )
{
va_list va;
va_start( va...