大约有 43,000 项符合查询结果（耗时：0.0378秒） [XML]
selecting unique values from a column
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Use the DISTINCT operator in MySQL:
SELECT DISTINCT(Date) AS Date FROM buy ORDER BY Date DESC;
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What is the error “Every derived table must have its own alias” in MySQL?
...er), which can the be used to refer to it in the rest of the outer query.
SELECT ID FROM (
SELECT ID, msisdn FROM (
SELECT * FROM TT2
) AS T
) AS T
In your case, of course, the entire query could be replaced with:
SELECT ID FROM TT2
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Removing duplicate rows from table in Oracle
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Use the rowid pseudocolumn.
DELETE FROM your_table
WHERE rowid not in
(SELECT MIN(rowid)
FROM your_table
GROUP BY column1, column2, column3);
Where column1, column2, and column3 make up the identifying key for each record. You might list all your columns.
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SQL Server loop - how do I loop through a set of records
how do I loop through a set of records from a select?
8 Answers
8
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What's the difference between KeyDown and KeyPress in .NET?
...ctical difference between KeyDown and KeyPress is that KeyPress relays the character resulting from a keypress, and is only called if there is one.
In other words, if you press A on your keyboard, you'll get this sequence of events:
KeyDown: KeyCode=Keys.A, KeyData=Keys.A, Modifiers=Keys.None
Key...
What is the fastest factorial function in JavaScript? [closed]
...n fac(n){
return(n<2)?1:fac(n-1)*n;
}
It's the simplest way (less characters / lines) I've found, only a function with one code line.
Edit:
If you really want to save some chars you can go with an Arrow Function (21 bytes):
f=n=>(n<2)?1:f(n-1)*n
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How do I wrap a selection with an HTML tag in Visual Studio?
...Studio 2015 comes with a new shortcut, Shift+Alt+W, that wraps the current selection with a div. This shortcut leaves the text "div" selected, making it seamlessly changeable to any desired tag. This coupled with the automatic end tag replacement makes for a quick solution.
UPDATE
This shortcut is a...
Finding duplicate values in a SQL table
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SELECT
name, email, COUNT(*)
FROM
users
GROUP BY
name, email
HAVING
COUNT(*) > 1
Simply group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY ...
PhpStorm wrap/surround selection?
... to wrap a certain part of text. Is there any shortcut to wrap the current selection, for example:
4 Answers
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How to change Android Studio's editor font?
...TRL + mouse wheel which is really easy to use it !!!
To use this feature select File -> Settings -> Editor -> General -> select the checkbox of Change the font size (Zoom) with Ctrl + Mouse Wheel
I hope it's helpful.
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