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Does MySQL ignore null values on unique constraints?
... '1' for key 'x'
INSERT table1 VALUES (NULL);
INSERT table1 VALUES (NULL);
SELECT * FROM table1;
Result:
x
NULL
NULL
1
This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.
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Haskell: How is pronounced? [closed]
... draft for the Vietnam war, in which unfortunate young men were collected, selected, sometimes rejected, and otherwise, injected.
– Tom Anderson
Nov 19 '18 at 16:15
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Create a nonclustered non-unique index within the CREATE TABLE statement with SQL Server
...s a separate statement.
It's also not possible to insert into a table and select from it and build an index in the same statement either.
The BOL entry contains the information you need:
CLUSTERED | NONCLUSTERED
Indicate that
a clustered or a nonclustered index is
created for the PRIMARY...
How does BLAS get such extreme performance?
... can have different settings). It tries different configurations and then selects the best for the particular target system.
(Tip: That is why if you are using ATLAS you are better off building and tuning the library by hand for your particular machine then using a prebuilt one.)
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Given final block not properly padded
...erivation in a defined manner (and a manner which is deemed secure, if you select the right algorithm).
Don't use ECB-mode. It encrypts each block independently, which means that identical plain text blocks also give always identical ciphertext blocks.
Preferably use a secure mode of operation, lik...
How to use sessions in an ASP.NET MVC 4 application?
...SP.NET MVC. I have used PHP before and it was easy to create a session and select user records based on the current session variables.
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How can I get Knockout JS to data-bind on keypress instead of lost-focus?
... "auto-populate" values ( like if the input field is named "firstname" ). selecting from the auto-populate doesnt work with "afterkeydown". is there a way to catch this?
– Anton
Sep 9 '12 at 0:01
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How can I see all the issues I'm watching on Github?
...m any page by clicking the notification/bell icon on the top left and then selecting "Managed Notification" > "Subscriptions" from the left menu panel.
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Repeater, ListView, DataList, DataGrid, GridView … Which to choose?
...plate
lnsertltemTemplate
ItemSeparatorTemplate
ItemTemplate
LayoutTemplate
SelectedltemTemplate
DataList (note the Style pairs)
AlternatingltemStyle
AlternatingltemTemplate
EditltemStyle
EditltemTemplate
FooterStyle
FooterTemplate
HeaderStyle
HeaderTemplate
ItemStyle
ItemTemplate
SelectedltemSty...
Simulator or Emulator? What is the difference?
...e than it is.
This comparison of both terms will contradict the currently selected answer (from Toybuilder) which puts the difference on the internal model, while my suggestion is that the difference is whether the fake can or cannot be used to perform the actual function in the actual world (to so...