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Unique constraint on multiple columns
...finition would be:
CREATE TABLE [dbo].[user](
[userID] [int] IDENTITY(1,1) NOT NULL,
[fcode] [int] NULL,
[scode] [int] NULL,
[dcode] [int] NULL,
[name] [nvarchar](50) NULL,
[address] [nvarchar](50) NULL,
CONSTRAINT [PK_user_1] PRIMARY KEY CLUSTERED
(
[userID...
Pure virtual destructor in C++
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edited Jul 25 '14 at 0:08
answered Mar 10 '09 at 16:04
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How to revert a Git Submodule pointer to the commit stored in the containing repository?
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167
You want to update your submodule so it is in sync with what the parent repository believes it...
Why prefer two's complement over sign-and-magnitude for signed numbers?
I'm just curious if there's a reason why in order to represent -1 in binary, two's complement is used: flipping the bits and adding 1?
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Bash conditionals: how to “and” expressions? (if [ ! -z $VAR && -e $VAR ])
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edited Dec 22 '14 at 22:36
answered Jan 19 '12 at 2:16
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How to write Unicode characters to the console?
...utputEncoding = System.Text.Encoding.UTF8;
for (var i = 0; i <= 1000; i++) {
Console.Write(Strings.ChrW(i));
if (i % 50 == 0) { // break every 50 chars
Console.WriteLine();
}
}
Console.ReadKey();
}
}
VB.NET
imports...
How does one generate a random number in Apple's Swift language?
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Swift 4.2+
Swift 4.2 shipped with Xcode 10 introduces new easy-to-use random functions for many data types.
You can call the random() method on numeric types.
let randomInt = Int.random(in: 0..<6)
let randomDouble = Double.random(in: 2.71828...3.14159)
let rand...
Sending “User-agent” using Requests library in Python
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341
The user-agent should be specified as a field in the header.
Here is a list of HTTP header fiel...
How can I filter a Django query with a list of values?
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From the Django documentation:
Blog.objects.filter(pk__in=[1, 4, 7])
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Updating MySQL primary key
...update the primary key.
alter table xx drop primary key, add primary key(k1, k2, k3);
To fix things:
create table fixit (user_2, user_1, type, timestamp, n, primary key( user_2, user_1, type) );
lock table fixit write, user_interactions u write, user_interactions write;
insert into fixit
selec...