大约有 40,000 项符合查询结果（耗时：0.0391秒） [XML]
When should I use a composite index?
...nefit a query that uses those fields for joining, filtering, and sometimes selecting. It will also benefit queries that use left-most subsets of columns in that composite. So the above index will also satisfy queries that need
index( column_A, column_B, column_C )
index( column_A, column_B )
index(...
How to find SQL Server running port?
...
This is the one that works for me:
SELECT DISTINCT
local_tcp_port
FROM sys.dm_exec_connections
WHERE local_tcp_port IS NOT NULL
share
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improve this ...
Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?
...@num2 DECIMAL(19,4),
@num3 DECIMAL(19,4),
@num4 DECIMAL(19,4)
SELECT
@mon1 = 100, @mon2 = 339, @mon3 = 10000,
@num1 = 100, @num2 = 339, @num3 = 10000
SET @mon4 = @mon1/@mon2*@mon3
SET @num4 = @num1/@num2*@num3
SELECT @mon4 AS moneyresult,
@num4 AS numericresult...
SQL - find records from one table which don't exist in another
...shortest statement, and may be quickest if your phone book is very short:
SELECT *
FROM Call
WHERE phone_number NOT IN (SELECT phone_number FROM Phone_book)
alternatively (thanks to Alterlife)
SELECT *
FROM Call
WHERE NOT EXISTS
(SELECT *
FROM Phone_book
WHERE Phone_book.phon...
Table name as variable
...mpare data between the same tables of different databases:
static query:
SELECT * FROM [DB_ONE].[dbo].[ACTY]
EXCEPT
SELECT * FROM [DB_TWO].[dbo].[ACTY]
since I want easily change tha name of table and schema I have created this dynamic query:
declare @schema varchar(50)
declare @table varchar(5...
Add primary key to existing table
...PMID)
edit:
you can find the constraint name by using the query below:
select OBJECT_NAME(OBJECT_ID) AS NameofConstraint
FROM sys.objects
where OBJECT_NAME(parent_object_id)='Persion'
and type_desc LIKE '%CONSTRAINT'
sh...
What is the difference between a “function” and a “procedure”?
... a Procedure, whereas in a Function we can't.
In SQL:
A Procedure allows SELECT as well as DML (INSERT, UPDATE, DELETE) statements in it, whereas Function allows only SELECT statement in it.
Procedures can not be utilized in a SELECT statement, whereas Functions can be embedded in a SELECT stateme...
How to get the index of an element in an IEnumerable?
...
extensions with overloads like Select((x, i) => ...) seem to imply that these indexes should exist
– Michael
Mar 19 '14 at 16:05
...
How to unstash only certain files?
... relative to stash@{0})).
yucer suggests in the comments:
If you want to select manually which changes you want to apply from that file:
git difftool stash@{0}..HEAD -- <filename>
Vivek adds in the comments:
Looks like "git checkout stash@{0} -- <filename>" restores the version of t...
How to select an element by classname using jqLite?
...y, and as-noted by @kevin-b:
// find('#id')
angular.element(document.querySelector('#id'))
//find('.classname'), assumes you already have the starting elem to search from
angular.element(elem.querySelector('.classname'))
Note: If you're looking to do this from your controllers you may want to ha...