大约有 531 项符合查询结果（耗时：0.0161秒） [XML]
MySQL “WITH” clause
...n Subquery please? could I have select * from ( (select * from table1) UNION ALL (select * from table2) ) Group By something?
– user677607
Jun 5 '12 at 20:54
1
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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...
Tricky Google interview question
...
let's just call this "merge" function union instead, as it is removing the duplicates. merge, as a part of mergesort, must preserve duplicates coming from both its input sequences. See Data.List.Ordered package for related stuff.
– Will Ness...
SQL is null and = null [duplicate]
...(null, 1), (1, 1);
select 'x = null' as test , x, y from t where x = null
union all
select 'x != null', x, y from t where x != null
union all
select 'not (x = null)', x, y from t where not (x = null)
union all
select 'x = y', x, y from t where x = y
union all
select 'not (x = y)', x, y from t where...
Select count(*) from multiple tables
...slightly different:
SELECT 'table_1' AS table_name, COUNT(*) FROM table_1
UNION
SELECT 'table_2' AS table_name, COUNT(*) FROM table_2
UNION
SELECT 'table_3' AS table_name, COUNT(*) FROM table_3
It gives the answers transposed (one row per table instead of one column), otherwise I don't think it's...
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
...le expression that returns these two dictionaries, merged (i.e. taking the union). The update() method would be what I need, if it returned its result instead of modifying a dictionary in-place.
...
SELECT * FROM X WHERE id IN (…) with Dapper ORM
...
connection.Query<int>(
@"select *
from (select 1 as Id union all select 2 union all select 3) as X
where Id in @Ids",
new { Ids = new int[] { 1, 2, 3 });
Will be translated to:
select *
from (select 1 as Id union all select 2 union all select 3) as X
where Id in ...
T-SQL: Opposite to string concatenation - how to split string into multiple records [duplicate]
... Pieces(pn, start, stop) AS (
SELECT 1, 1, CHARINDEX(@sep, @s)
UNION ALL
SELECT pn + 1, stop + 1, CHARINDEX(@sep, @s, stop + 1)
FROM Pieces
WHERE stop > 0
)
SELECT pn,
SUBSTRING(@s, start, CASE WHEN stop > 0 THEN stop-start ELSE 512 END) AS s
FRO...
The opposite of Intersect()
..., then this should do the trick:
var nonintersect = array1.Except(array2).Union( array2.Except(array1));
This will not be the most performant solution, but for small lists it should work just fine.
share
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Oracle Differences between NVL and Coalesce
...guments to be of same datatype.
COALESCE gives issues in queries which use UNION clauses. Example
below
COALESCE is ANSI standard where as NVL is Oracle specific.
Examples for the third case. Other cases are simple.
select nvl('abc',10) from dual; would work as NVL will do an implicit conversion ...