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Difference between database and schema
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A database is the main container, it contains the data and log files, and all the schemas within it. You always back up a database, it is a discrete unit on its own.
Schemas are like folders within a database, and are mainly used to group logical objects together, which leads to ease of setting pe...
PostgreSQL: Show tables in PostgreSQL
...terface,
First, choose your database
\c database_name
Then, this shows all tables in the current schema:
\dt
Programmatically (or from the psql interface too, of course):
SELECT * FROM pg_catalog.pg_tables;
The system tables live in the pg_catalog database.
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Select DISTINCT individual columns in django?
...g note in the docs about using distinct(). The above example will work but all combinations of distinct() and values() may not.
PS: it is a good idea to use lower case names for fields in a model. In your case this would mean rewriting your model as shown below:
class ProductOrder(models.Model):
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Difference between shadowing and overriding in C#?
...dow
public override int Bar() {return 1;} //override
}
then when you call this:
A clA = new A();
B clB = new B();
Console.WriteLine(clA.Foo()); // output 5
Console.WriteLine(clA.Bar()); // output 5
Console.WriteLine(clB.Foo()); // output 1
Console.WriteLine(clB.Bar()); // output 1
//now let'...
Declaring Multiple Variables in JavaScript
...ou're writing code that you expect to minify or pack later, the second way allows compressors (like the YUI Compressor) to give you a more minified version. If size is a consideration, then I would suggest following as many of JSLint's suggestions as possible.
– Lane
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How does “make” app know default target to build if no target is specified?
...e default goal; to do that, it may have to process other targets - specifically, ones the first target depends on.
The GNU Make Manual covers all this stuff, and is a surprisingly easy and informative read.
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How to test if parameters exist in rails
...re asking about existence. You might need to differentiate:
Not there at all.
There but nil.
There but false.
There but an empty string.
as well. Hard to say without more details of your precise situation.
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Print the contents of a DIV
...rs later, this will produce "a.browser is undefined" because the .browser call has been removed in jquery 1.9
– KingsInnerSoul
Aug 24 '18 at 20:58
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Resizing an image in an HTML5 canvas
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So what do you do if all the browsers (actually, Chrome 5 gave me quite good one) won't give you good enough resampling quality? You implement them yourself then! Oh come on, we're entering the new age of Web 3.0, HTML5 compliant browsers, super ...
Count the items from a IEnumerable without iterating?
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I usually just grab List and IList out of habit. But especially if you want to implement them yourself ICollection is easier and also has the Count property. Thanks!
– Mendelt
Oct 3 '08 at 22...