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by: Agoston Bejo |
last post by:
I want to enforce such a constraint on a column that would ensure that the
values be all unique, but this wouldn't apply to NULL values. (I.e. there
may be more than one NULL value in the column.)
How can I achieve this?
I suppose I would get the most-hated "table/view is changing,
trigger/function may not see it" error if I tried to write a...
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by: Alex82 |
last post by:
I can't use it....for example i have to create a column that accept values
between 1 to 120...i can't enumerate all of them....or i have to accept a
value different from NULL if an other column has a certain values, otherwise
the first must be NULL, it's impossible to use enum to do this!
----- Original Message -----
From: "Michael Brunson"...
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by: A.M. de Jong |
last post by:
Reading a lot about Nulls right now I still can't find a Technical reason to
use it or not.
For what I've understand is this:
In an Ingres database a Null column has a standard extra storage of 2 Bits.
In a SQL Server database every column has a NULL-bit telling about this
column it is NULL or NOT.
That means that a varchar-empty...
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by: iStrain |
last post by:
Hiya. I'm _sure_ this is an FAQ, but Googling hasn't produced the
answer in a way I can make sense out of. I know I should get this, but
so far no way...
I'm creating tables and doing queries in Perl, and Nulls have started
to bother me greatly. The first issue is, as far as I understand it, a
column should be NOT NULL if it is necessary...
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by: sianan |
last post by:
I tried to use the following example, to add a checkbox column to a
DataGrid in an ASP.NET application:
http://www.codeproject.com/aspnet/datagridcheckbox.asp
For some reason, I simply CAN'T get the example to work. I created the
following two classes, provided with the example:
*-*-**-*-*-*-*-*-*-*-*-*-**-*-*-*-*-CheckBoxColumn...
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by: Edmund Dengler |
last post by:
Greetings!
Just trying some tests out, and wanted to know about some optimizations.
If I do a CHECK constraint on a table, is this used to optimize a SELECT
or does Postgresql rely mostly on normal index search?
For example, I want to create some tables to manage different data in a
kind of <object, relationship, object2> manner, but...
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by: Daniel Martini |
last post by:
Hi all,
I'm currently coding some functions in plpgsql for generating
reports out of records in a table. Problem is: NULL values in
records make the complete function fail.
Here is a simple test case (original is more complex with a multi-
table query in the for qres in select... part):
create table test(
id serial,
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by: Susanne Klemm |
last post by:
Hi!
I have a table with a check constraint. But unfortunately it does not
work like I wanted.
CREATE TABLE MAP
(
NOT NULL,
NULL,
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by: ferg |
last post by:
I have a Customer table. The table has two different CHECK constraints.
Then there is the Customer details dialog, which provides the user with
an UI for changing users. I have some UPDATE sql, which is called once
the user clicks the OK button on this dialog.
try
{
int rows = cmd.ExecuteNonQuery();
}
catch(SqlException se)
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by: =?Utf-8?B?UGV0ZXJX?= |
last post by:
I have a TabControl on a Windows form in which I have various tab pages each
with a DataGridView, the first column of which is a
DataGridViewCheckBoxColumn and subsequent columns being
DataGridViewtextBoxColumns.
In each case the properties of the CheckBoxcolumn have been set to not allow
nulls, so presumably only explicit true or false...
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by: marktang |
last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main...
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by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language...
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by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it. ...
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by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that...
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by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For...
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by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then...
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by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules.
He will explain when you may want to use classes...
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by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert...
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by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
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