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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... using Standard SQL.
An obvious omission is the equivalent using EXCEPT:
SELECT a FROM table1
EXCEPT
SELECT a FROM table2
Note in Oracle you need to use the MINUS operator (arguably a better name):
SELECT a FROM table1
MINUS
SELECT a FROM table2
Speaking of proprietary syntax, there may also ...
How to make an introduction page with Doxygen
...e are multiple mainpage candidates, the first encountered while parsing is selected, or so it seems.
– Lester Peabody
Sep 3 '15 at 19:09
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How can I check MySQL engine type for a specific table?
...st of all the tables in a database and their engines, use this SQL query:
SELECT TABLE_NAME,
ENGINE
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'dbname';
Replace dbname with your database name.
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...
std::string to float or double
...e temp = winOpacity.toDouble();
Extra note:
If the input data is a const char*, QByteArray::toDouble will be faster.
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OSX - How to auto Close Terminal window after the “exit” command executed.
...
in Terminal.app
Preferences > Profiles > (Select a Profile) > Shell.
on 'When the shell exits' chosen 'Close the window'
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Array or List in Java. Which is faster?
...;std::string>, although copying by value without a pointer as such, the character arrays will form an object for string (and these will not usually be shared).
If this particular code is really performance-sensitive, you could create a single char[] array (or even byte[]) for all the characters ...
Android YouTube app Play Video Intent
...Tube app for my emulator, or...
2. What is the intent used when the user selects a video for playback.
18 Answers
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Parse large JSON file in Nodejs
...s answer with JSONStream + event-stream. I modified the JSONPath query to select only what I needed. This time the memory never went higher than 82MB, however, the whole thing now took 70 seconds to complete!
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How to check for Is not Null And Is not Empty string in SQL server?
... ('A'),
(''),
(' '),
(NULL);
SELECT *
FROM T
WHERE C <> ''
Returns just the single row A. I.e. The rows with NULL or an empty string or a string consisting entirely of spaces are all excluded by this query.
SQL Fiddle
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What are the uses for Cross Join?
...ly, like size and color information for a particular article of clothing:
select
size,
color
from
sizes CROSS JOIN colors
Maybe you want a table that contains a row for every minute in the day, and you want to use it to verify that a procedure has executed each minute, so you might c...