大约有 12,000 项符合查询结果（耗时：0.0130秒） [XML]
Sql Server string to date conversion
...what you're looking for. It wont be hard to adapt:
Declare @d datetime
select @d = getdate()
select @d as OriginalDate,
convert(varchar,@d,100) as ConvertedDate,
100 as FormatValue,
'mon dd yyyy hh:miAM (or PM)' as OutputFormat
union all
select @d,convert(varchar,@d,101),101,'mm/dd/yy'
union al...
Turning a Comma Separated string into individual rows
... SomeID INT,
OtherID INT,
String VARCHAR(MAX)
)
INSERT Testdata SELECT 1, 9, '18,20,22'
INSERT Testdata SELECT 2, 8, '17,19'
INSERT Testdata SELECT 3, 7, '13,19,20'
INSERT Testdata SELECT 4, 6, ''
INSERT Testdata SELECT 9, 11, '1,2,3,4'
The query
;WITH tmp(SomeID, OtherID, DataIt...
How to find largest objects in a SQL Server database?
...quite a bit understanding and determining the size of indices and tables:
SELECT
t.name AS TableName,
i.name as indexName,
sum(p.rows) as RowCounts,
sum(a.total_pages) as TotalPages,
sum(a.used_pages) as UsedPages,
sum(a.data_pages) as DataPages,
(sum(a.total_pages) *...
What are the use cases for selecting CHAR over VARCHAR in SQL?
...'123 Main St Washington, MD 12345', 123.45)
create view vwStagingTable AS
SELECT CustomerFirstName = CAST(CustomerFirstName as CHAR(30)),
CustomerLastName = CAST(CustomerLastName as CHAR(30)),
CustomerCityStateZip = CAST(CustomerCityStateZip as CHAR(100)),
CustomerCurrentBalance = CAST(CAST(Custome...
Why does String.valueOf(null) throw a NullPointerException?
...s
How does polymorph ambiguity distinction work?
Which overload will get selected for null in Java?
Moral of the story
There are several important ones:
Effective Java 2nd Edition, Item 41: Use overloading judiciously
Just because you can overload, doesn't mean you should every time
They ...
Correct use of Multimapping in Dapper
...
I just ran a test that works fine:
var sql = "select cast(1 as decimal) ProductId, 'a' ProductName, 'x' AccountOpened, cast(1 as decimal) CustomerId, 'name' CustomerName";
var item = connection.Query<ProductItem, Customer, ProductItem>(sql,
(p, c) => { p.Cu...
How to use GROUP BY to concatenate strings in SQL Server?
...S (1,'B',8)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (2,'C',9)
SELECT
[ID],
STUFF((
SELECT ', ' + [Name] + ':' + CAST([Value] AS VARCHAR(MAX))
FROM #YourTable
WHERE (ID = Results.ID)
FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
,1,2,'') AS NameVa...
PostgreSQL return result set as JSON array?
...
TL;DR
SELECT json_agg(t) FROM t
for a JSON array of objects, and
SELECT
json_build_object(
'a', json_agg(t.a),
'b', json_agg(t.b)
)
FROM t
for a JSON object of arrays.
List of objects
This section de...
Why does dividing two int not yield the right value when assigned to double?
...oo(int);
void foo(double);
void (*p)(double) = &foo; // automatically selects `foo(fouble)`
This is one context where the left-hand side of an assignment/initialization affects the behavior of the right-hand side. (Also, reference-to-array initialization prevents array type decay, which is an...
Unable to Cast from Parent Class to Child Class
...
I think the examples are a bit extreme and selective and perhaps the cast is a shortcut for a copy constructor. For example, being building a ferrari with the properties defined in base object car. Or, start with a human and create a Boy. Casting and direct use? A...