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Difference between View and table in sql
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A table contains data, a view is just a SELECT statement which has been saved in the database (more or less, depending on your database).
The advantage of a view is that it can join data from several tables thus creating a new view of it. Say you have a database w...
Is it possible to GROUP BY multiple columns using MySQL?
Is it possible to GROUP BY more than one column in a MySQL SELECT query? For example:
7 Answers
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Join between tables in two different databases?
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Yes, assuming the account has appropriate permissions you can use:
SELECT <...>
FROM A.table1 t1 JOIN B.table2 t2 ON t2.column2 = t1.column1;
You just need to prefix the table reference with the name of the database it resides in.
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How to see full query from SHOW PROCESSLIST
... pull the data and look at 'INFO' column which contains the whole query :
select * from INFORMATION_SCHEMA.PROCESSLIST where db = 'somedb';
You can add any condition or ignore based on your requirement.
The output of the query is resulted as :
+-------+------+-----------------+--------+--------...
Add an already existing directory to a directory in Solution Explorer
...tory in Solution Explorer, but whenever I right-click on the directory and select Add => Existing Item , I can only add individual files, but not directories.
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How to install Xcode Command Line Tools
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Xcode 5.1 and OSX 10.9. (also works with Xcode 5.1.1 + OSX 10.10)
xcode-select --install worked with version 2333, failed with version 2003. So, try xcode-select --install and if that does not work download as described below.
In early February 2014 xcode-select --install has been reporting that...
PostgreSQL: insert from another table
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Just supply literal values in the SELECT:
INSERT INTO TABLE1 (id, col_1, col_2, col_3)
SELECT id, 'data1', 'data2', 'data3'
FROM TABLE2
WHERE col_a = 'something';
A select list can contain any value expression:
But the expressions in the select list do...
Warning: Null value is eliminated by an aggregate or other SET operation in Aqua Data Studio
...t the solution specifically for the "opencases" column be simpler as just "select count(1)..." (or "count" of any other literal)? The Where clause already specifies "and closed is NULL" so no need for summing a case statement in this instance. Also, I've heard (aeons ago) that "count(*)" is not as e...
How to fix .pch file missing on build?
...the bottom of the drop-down menu.
At the top left of the Properties Pages,
select All Configurations from the drop-down menu.
Open the C/C++ tree and select Precompiled Headers
Precompiled Header: Select Use (/Yu)
Fill in the Precompiled Header File field. Standard is stdafx.h
Click Okay
If you do n...
Why can't radio buttons be “readonly”?
...ton by disabling only the un-checked radio buttons. It keeps the user from selecting a different value, and the checked value will always post on submit.
Using jQuery to make readonly:
$(':radio:not(:checked)').attr('disabled', true);
This approach also worked for making a select list readonly, ...