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Rails :include vs. :joins
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.joins will just joins the tables and brings selected fields in return. if you call associations on joins query result, it will fire database queries again
:includes will eager load the included associations and add them in memory. :includes loads all the included tabl...
Xcode : failed to get the task for process
...two Provisioning Profiles for the same name, Xcode5 will only allow you to select one of them. To work around this, you have to use iPhone Configuration Utility to find the Profile you want, find the 30-digit "Profile Identifier" and copy/paste it into the "Other" value of the Provisioning Profile d...
How to post pictures to instagram using API
...cking on chrome.
From top right corener menu drop down on developer tools, select more tool.
Further select network conditions.
In the network selection section, see the second section there named user agent.
Uncheck select automatically, and select chrome for Android from the list of given user age...
Is there a MySQL option/feature to track history of changes to records?
...i AFTER INSERT ON MyDB.data FOR EACH ROW
INSERT INTO MyDB.data_history SELECT 'insert', NULL, NOW(), d.*
FROM MyDB.data AS d WHERE d.primary_key_column = NEW.primary_key_column;
CREATE TRIGGER MyDB.data__au AFTER UPDATE ON MyDB.data FOR EACH ROW
INSERT INTO MyDB.data_history SELECT 'up...
SQL Server IN vs. EXISTS Performance
...execution operation, to get their results.
An example:
Query 1 ( plan )
select * from dt where dt.customer in (select c.code from customer c where c.active=0)
Query 2 ( plan )
select * from dt where exists (select 1 from customer c where c.code=dt.customer and c.active=0)
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How can I clone an SQL Server database on the same server in SQL Server 2008 Express?
...is optional.
Click to clone database and open restore dialog (see image)
Select Device and add the backup file from step 3.
Change destination to test database
Change location of database files, it must be different from the original. You can type directly into text box, just add postfix. (NOTE:...
Binding a WPF ComboBox to a custom list
I have a ComboBox that doesn't seem to update the SelectedItem/SelectedValue.
4 Answers
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Dynamic type languages versus static type languages
...o override the static checker. For most languages, these take the form of casting, though some (like C# and Haskell) have entire modes which are marked as "unsafe".
Subjectively, I like static typing. Implemented properly (hint: not Java), a static type system can be a huge help in weeding out er...
More lines in command window
...and go to properties.
Click the Options tab.
In Command History, type or select 999 in Buffer Size, and then type or select 5 in Number of Buffers.
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Sublime Text 2: How to delete blank/empty lines
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Select the text
Press:
Ctrl + H on PC, or
Command + Alt + F on Mac or
Click Find->Replace.
Make sure you have selected 'regular expression' by pressing:
Alt + R on PC or
Command + Alt + R on Mac or
Click .* in the Find ...