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Real life example, when to use OUTER / CROSS APPLY in SQL
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Some uses for APPLY are...
1) Top N per group queries (can be more efficient for some cardinalities)
SELECT pr.name,
pa.name
FROM sys.procedures pr
OUTER APPLY (SELECT TOP 2 *
FROM sys.parameters...
SQL join: selecting the last records in a one-to-many relationship
...er id). When we find that to be true, then p1 is the most recent purchase for that customer.
Regarding indexes, I'd create a compound index in purchase over the columns (customer_id, date, id). That may allow the outer join to be done using a covering index. Be sure to test on your platform, bec...
When and why I should use session_regenerate_id()?
...lace the current session ID with a new one, and keep the current session information.
What does it do?
It mainly helps prevent session fixation attacks. Session fixation attacks is where a malicious user tries to exploit the vulnerability in a system to fixate (set) the session ID (SID) of another u...
Custom toast on Android: a simple example
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toast.setView(layout);
toast.show();
And check out the below links also for a custom Toast.
Custom Toast with Analog Clock
YouTube: Creating Custom Toast With Button in Android Studio
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CodeIgniter activerecord, retrieve last insert id?
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the userguide is your best friend for things like this. i have been using codeigniter for 2+ years and i still find functions like this that i never knew about.
– Tom Schlick
Jan 3 '10 at 10:02
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JavaScript loop through json array?
...romWho": "hello2@email.se"
}];
You can loop over the Array like this:
for(var i = 0; i < json.length; i++) {
var obj = json[i];
console.log(obj.id);
}
Or like this (suggested from Eric) be careful with IE support
json.forEach(function(obj) { console.log(obj.id); });
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How do I search for an object by its ObjectId in the mongo console?
I've found this question answered for C# and Perl, but not in the native interface. I thought this would work:
12 Answers
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Objective-C: difference between id and void *
...Under GC Only or GC Supported modes, the compiler will emit write barriers for references of type id, but not for type void *. When declaring structures, this can be a critical difference. Declaring iVars like void *_superPrivateDoNotTouch; will cause premature reaping of objects if _superPrivat...
Passing an array to a query using a WHERE clause
...s are still a quoted list, so it comes out as "WHERE id IN ( '1,2,3,4' )", for example. You need to quote each identifier separately, or else ditch the quotes inside the parentheses.
– Rob
May 25 '09 at 20:05
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MySQL ON vs USING?
...o. One can join tables ON a column, a set of columns and even a condition. For example:
SELECT * FROM world.City JOIN world.Country ON (City.CountryCode = Country.Code) WHERE ...
USING is useful when both tables share a column of the exact same name on which they join. In this case, one may say:
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