by: Westcoast Sheri |
last post by:
Which will be a faster lookup of an item by, "color" in the following
mySQL tables: "unique key," "primary key," or just plain "key"??
CREATE TABLE myTable (
number int(11) NOT NULL default '0',...
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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.)...
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by: Mansoor Azam |
last post by:
When I add a unique key constraint to column in SQL 6.5 why does it also
create an index. e.g. In the table subaccounts I added a unique key
constraint for the column login and SQL creates an index...
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by: Q. John Chen |
last post by:
All,
What's the difference between a unique contraint and unique?
sementically, if you want a column contain unique values, it is a
contraint. And an index is for searching/sort. The questions...
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by: Laurent |
last post by:
DB2 8.1
-------
db2 => create table test (COL1 VARCHAR(10))
db2 => insert into test values ('A')
db2 => insert into test values ('A ')
db2 => insert into test values ('B')
db2 => insert into...
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by: aj |
last post by:
DB2 WSE 8.1 FP5
Red Hat AS 2.1
What is the difference between adding a unique constraint like:
ALTER TABLE <SCHEMA>.<TABLE> ADD CONSTRAINT CC1131378283225 UNIQUE (
<COL1>) ;
and adding a...
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by: D.Stone |
last post by:
Hi, I'm getting hung up on a trivial schema change - I need to make a
column accept only null or unique values and Books Online avers 'what
you need is a UNIQUE constraint'. Fine.
I've tried...
|
by: muzu1232004 |
last post by:
If I have a table t1 with a column a as follows
A
1
1
1
1
1
1
1
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by: Gabriel Genellina |
last post by:
En Fri, 18 Apr 2008 12:23:08 -0300, Shawn Milochik <Shawn@Milochik.comescribió:
A dictionary with keys is perfectly reasonable. But a *list* of values has to be searched linearly for every...
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by: Alvin SIU |
last post by:
Hi all,
I have a table in Db2 v8 like this:
Team Name Role
------ -------- ---------------------
A Superman Leader
A Batman Member
A WonderWoman Member
B ...
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by: Charles Arthur |
last post by:
How do i turn on java script on a villaon, callus and itel keypad mobile phone
|
by: ryjfgjl |
last post by:
In our work, we often receive Excel tables with data in the same format. If we want to analyze these data, it can be difficult to analyze them because the data is spread across multiple Excel files...
|
by: emmanuelkatto |
last post by:
Hi All, I am Emmanuel katto from Uganda. I want to ask what challenges you've faced while migrating a website to cloud.
Please let me know.
Thanks!
Emmanuel
|
by: Hystou |
last post by:
There are some requirements for setting up RAID:
1. The motherboard and BIOS support RAID configuration.
2. The motherboard has 2 or more available SATA protocol SSD/HDD slots (including MSATA, M.2...
|
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,...
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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...
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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,...
|
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...
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by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
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