大约有 44,000 项符合查询结果（耗时：0.0403秒） [XML]
Condition within JOIN or WHERE
...of filtering criteria more easily maintainable.
For example, instead of:
SELECT *
FROM Customers c
INNER JOIN CustomerAccounts ca
ON ca.CustomerID = c.CustomerID
AND c.State = 'NY'
INNER JOIN Accounts a
ON ca.AccountID = a.AccountID
AND a.Status = 1
Write:
SELECT *
FROM Customer...
How can I clear or empty a StringBuilder? [duplicate]
...eap! How can you say that? Suppose you have a buffer with capacity of 1000 chars. Then you dispose of it (work for GC) and create a new one (work for allocator). It's a lot faster just to set the text length to zero (virtually no work for CPU) and reuse the same buffer.
– Sulth...
Named placeholders in string formatting
...
Had trouble with the ' char: unexpected char: '''
– AlikElzin-kilaka
Jan 18 '16 at 10:35
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iOS JavaScript bridge
...NSString *)bar;
- (void)testfoo;
+ (BOOL)isKeyExcludedFromWebScript:(const char *)name;
+ (BOOL)isSelectorExcludedFromWebScript:(SEL)aSelector;
+ (WebScriptBridge*)getWebScriptBridge;
@end
static WebScriptBridge *gWebScriptBridge = nil;
@implementation WebScriptBridge
- (void)someEvent: (uint64_t)...
Which method performs better: .Any() vs .Count() > 0?
...re generated SQLs. Beauties as you can see ;)
ANY:
exec sp_executesql N'SELECT TOP (1)
[Project2].[ContactId] AS [ContactId],
[Project2].[CompanyId] AS [CompanyId],
[Project2].[ContactName] AS [ContactName],
[Project2].[FullName] AS [FullName],
[Project2].[ContactStatusId] AS [ContactStatusI...
How do you create a dropdownlist from an enum in ASP.NET MVC?
...pDownListFor
@Html.EnumDropDownListFor(
x => x.YourEnumField,
"Select My Type",
new { @class = "form-control" })
For MVC v5 use EnumHelper
@Html.DropDownList("MyType",
EnumHelper.GetSelectList(typeof(MyType)) ,
"Select My Type",
new { @class = "form-control" })
...
How do you return the column names of a table?
...
Not sure if there is an easier way in 2008 version.
USE [Database Name]
SELECT COLUMN_NAME,*
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'YourTableName' AND TABLE_SCHEMA='YourSchemaName'
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...
LEFT OUTER JOIN in LINQ
...c.Category equals p.Category into ps
from p in ps.DefaultIfEmpty()
select new { Category = c, ProductName = p == null ? "(No products)" : p.ProductName };
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improve this answer
...
How do I find a default constraint using INFORMATION_SCHEMA?
...our constraints!)
-- returns name of a column's default value constraint
SELECT
default_constraints.name
FROM
sys.all_columns
INNER JOIN
sys.tables
ON all_columns.object_id = tables.object_id
INNER JOIN
sys.schemas
ON tables.schema_id = schemas.s...
SQL Group By with an Order By
...
In all versions of MySQL, simply alias the aggregate in the SELECT list, and order by the alias:
SELECT COUNT(id) AS theCount, `Tag` from `images-tags`
GROUP BY `Tag`
ORDER BY theCount DESC
LIMIT 20
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...