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Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法 - 数据库(内核) - 清...
Oracle取前N条记录方法 Oracle实现SELECT TOP N的方法select * from ( select * from tablexxx order by xxx desc ) where rownum <= Noracle数据库不支持mysql中limit, top功...select * from ( select * from tablexxx order by xxx desc ) where rownum <= N
oracle数据库不支持mysql中li...
SQL Server: Query fast, but slow from procedure
...:
CREATE PROCEDURE GetOrderForCustomers(@CustID varchar(20))
AS
BEGIN
SELECT *
FROM orders
WHERE customerid = @CustID
END
Fast way:
CREATE PROCEDURE GetOrderForCustomersWithoutPS(@CustID varchar(20))
AS
BEGIN
DECLARE @LocCustID varchar(20)
SET @LocCustID = @CustID
SELEC...
Stored procedure slow when called from web, fast from Management Studio
...ariables.
eg. change:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
SELECT * FROM Table WHERE ID = @param1
to:
ALTER PROCEDURE [dbo].[sproc]
@param1 int,
AS
DECLARE @param1a int
SET @param1a = @param1
SELECT * FROM Table WHERE ID = @param1a
Seems strange, but it fixed my problem.
...
How can I do an UPDATE statement with JOIN in SQL Server?
...oesn't support MERGE):
ANSI/ISO:
update ud
set assid = (
select sale.assid
from sale
where sale.udid = ud.id
)
where exists (
select *
from sale
where sale.udid = ud.id
);
MySQL:
update ud u
inner join sale s on
u.id = s.udid
...
How to build jars from IntelliJ properly?
...from IntelliJ:
Go to project structure:
Create a new artifact:
Select the main class, and be sure to change the manifest folder:
You have to change manifest directory:
<project folder>\src\main\java
replace "java" with "resources"
<project folder>\src\main\resources
...
Postgresql aggregate array
...
Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as marks
FROM student s
LEFT JOIN Grade g ON g.Student_id = s.Id
GROUP BY s.Id
By the way, if you are using Postgres 9.1, you don't need to repeat the columns on SELECT to GROUP BY,...
Maximum Year in Expiry Date of Credit Card
...orget that in most browsers you can still key in the number and it'll auto select.
– Kevin Wiskia
Mar 22 '11 at 19:44
1
...
Emacs on Mac OS X Leopard key bindings
...
⌘ + → - move to end of current line
Shift + any of the above extend selection by appropriate amount
Click then drag - select text
Double-click then drag - select text, wrapping to word ends
Triple-click then drag - select text, wrapping to paragraph ends
Shift + Select text with mouse - add...
What makes a SQL statement sargable?
...non-sargable is to include a field inside a function in the where clause:
SELECT ... FROM ...
WHERE Year(myDate) = 2008
The SQL optimizer can't use an index on myDate, even if one exists. It will literally have to evaluate this function for every row of the table. Much better to use:
WHERE myDat...
Rebuild or regenerate 'ic_launcher.png' from images in Android Studio
...s a dialog where the app\src\main\res Directory Structure is automatically selected (the right choice)
Clicking on the OK button, AS opens the Asset Studio dialog where you can find all the tools and options we had on the past Eclipse ADT
This can be done absolutely in any moments after creation o...