大约有 40,000 项符合查询结果（耗时：0.0204秒） [XML]
nvarchar和varchar相互转换、联合查询 - ORACLE - 清泛IT论坛，有思想、有深度
...atype is NVARCHAR2.
（A表字段c_xxx:varchar，B表c_xxx:nvarchar）
select translate(c_xxx USING NCHAR_CS) from A
union all
select c_xxx from B
或者
select c_xxx from A
union all
select translate(c_xxx USING CHAR_CS) from B
注意：translate函数括号中没有逗号。
1、...
Difference between a Structure and a Union
Is there any good example to give the difference between a struct and a union ?
Basically I know that struct uses all the memory of its member and union uses the largest members memory space. Is there any other OS level difference?
...
Detecting endianness programmatically in a C++ program
...punning - it will often be warned against by compiler. That's exactly what unions are for !
bool is_big_endian(void)
{
union {
uint32_t i;
char c[4];
} bint = {0x01020304};
return bint.c[0] == 1;
}
The principle is equivalent to the type case as suggested by others, ...
Splitting string into multiple rows in Oracle
... be an improved way (also with regexp and connect by):
with temp as
(
select 108 Name, 'test' Project, 'Err1, Err2, Err3' Error from dual
union all
select 109, 'test2', 'Err1' from dual
)
select distinct
t.name, t.project,
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value...
Unioning two tables with different number of columns
...
Add extra columns as null for the table having less columns like
Select Col1, Col2, Col3, Col4, Col5 from Table1
Union
Select Col1, Col2, Col3, Null as Col4, Null as Col5 from Table2
share
|
...
LISTAGG in Oracle to return distinct values
...
19c and later:
select listagg(distinct the_column, ',') within group (order by the_column)
from the_table
18c and earlier:
select listagg(the_column, ',') within group (order by the_column)
from (
select distinct the_column
from t...
Iterate two Lists or Arrays with one ForEach statement in C#
...Zip method msdn.microsoft.com/en-us/library/dd267698.aspx and return resultSelector(first, second) instead of a KVP.
– Martín Coll
Jun 12 '13 at 19:17
...
What are POD types in C++?
... PODs,
enums are PODs
a const or volatile POD is a POD.
a class, struct or union of PODs is a POD provided that all non-static data members are public, and it has no base class and no constructors, destructors, or virtual methods. Static members don't stop something being a POD under this rule. This...
How to report an error from a SQL Server user-defined function
... For an inline-table-valued-function where the RETURN is a simple select, this alone doesn't work because nothing is returned - not even null, and in my case I wanted to throw an error when nothing was found. I didn't want to break down the inline function into a multi-statment one for obv...
Insert multiple rows WITHOUT repeating the “INSERT INTO …” part of the statement?
...
INSERT INTO dbo.MyTable (ID, Name)
SELECT 123, 'Timmy'
UNION ALL
SELECT 124, 'Jonny'
UNION ALL
SELECT 125, 'Sally'
For SQL Server 2008, can do it in one VALUES clause exactly as per the statement in your question (you just need to add a comma to separate eac...