大约有 44,000 项符合查询结果（耗时：0.0381秒） [XML]
Select distinct using linq [duplicate]
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myList.GroupBy(test => test.id)
.Select(grp => grp.First());
Edit: as getting this IEnumerable<> into a List<> seems to be a mystery to many people, you can simply write:
var result = myList.GroupBy(test => test.id)
.S...
Join vs. sub-query
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@JinghuiNiu Customers who bought expensive items: select custid from cust join bought using (custid) where price > 500. If a customer bought multiple expensive items, you'll get double-ups. To fix this, select custid from cust where exists (select * from bought where cust...
How can I set the value of a DropDownList using jQuery?
... have described above, yet the range validator keeps failing telling me to select a value (when the value selected is within range). Please see my question stackoverflow.com/questions/3165033/…
– James
Jul 7 '10 at 13:14
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How important is the order of columns in indexes?
I've heard that you should put columns that will be the most selective at the beginning of the index declaration. Example:
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How to paste text to end of every line? Sublime 2
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Yeah Regex is cool, but there are other alternative.
Select all the lines you want to prefix or suffix
Goto menu Selection -> Split into Lines (Cmd/Ctrl + Shift + L)
This allows you to edit multiple lines at once. Now you can add *Quotes (") or anything * at start and end...
Emacs on Mac OS X Leopard key bindings
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⌘ + → - 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...
Rename package in Android Studio
...n:
In your Project pane, click on the little gear icon ( )
Uncheck / De-select the Compact Empty Middle Packages option
Your package directory will now be broken up in individual directories
Individually select each directory you want to rename, and:
Right-click it
Select Refactor
Click o...
MySQL JOIN the most recent row only?
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You may want to try the following:
SELECT CONCAT(title, ' ', forename, ' ', surname) AS name
FROM customer c
JOIN (
SELECT MAX(id) max_id, customer_id
FROM customer_data
GROUP BY customer_id
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Query to count the number of tables I have in MySQL
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SELECT COUNT(*) FROM information_schema.tables WHERE table_schema = 'dbName';
Source
This is mine:
USE databasename;
SHOW TABLES;
SELECT FOUND_ROWS();
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Can we have multiple “WITH AS” in single sql - Oracle SQL
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You can do this as:
WITH abc AS( select
FROM ...)
, XYZ AS(select
From abc ....) /*This one uses "abc" multiple times*/
Select
From XYZ.... /*using abc, XYZ multiple times*/
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