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.)...
|
by: Kamil |
last post by:
Hello
What should I use for better perfomance since
unique constraint always use index ?
Thanks
Kamil
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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...
|
by: Joăo Santa Bárbara |
last post by:
Hi all
i have a problem with my sql dataadapter, i think.
i have this table below ( Script ) and this table has one particularity, it
has 2 unique constraints.
when i´m filling my datatable...
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by: Mark A |
last post by:
UNIQUE WHERE NOT NULL is supported in DB2 for z/OS, which allows for
duplicate null values to exist on a unique constraint.
Anyone know if or when this is coming to DB2 for LUW?
|
by: BuddhaBuddy |
last post by:
Platform is DB2/NT 7.2.9
The table was created like this:
CREATE TABLE MYTEST (
MYTESTOID bigint not null primary key,
FK_OTHEROID bigint not null references other,
FK_ANOTHEROID bigint not...
|
by: deko |
last post by:
I have a Make Table query that creates a fairly large table. The Make Table
query populates the new table with one AutoNumber field (which is taken form
another unrelated table as part of the...
|
by: deko |
last post by:
I'd like to use DDL (Data Definition Language) rather than VBA code to create a
new table. The below DDL statement creates the table very nicely:
CREATE TABLE tblTx03 (Subject Text (100),...
|
by: Laurence |
last post by:
Hi there,
How to differentiate between unique constraint and unique index? These
are very similar but I cannot differentiate them?
Could someone give me a hand?
Thanks in advance
|
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:
If we have dozens or hundreds of excel to import into the database, if we use the excel import function provided by database editors such as navicat, it will be extremely tedious and time-consuming...
|
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: BarryA |
last post by:
What are the essential steps and strategies outlined in the Data Structures and Algorithms (DSA) roadmap for aspiring data scientists? How can individuals effectively utilize this roadmap to progress...
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by: Sonnysonu |
last post by:
This is the data of csv file
1 2 3
1 2 3
1 2 3
1 2 3
2 3
2 3
3
the lengths should be different i have to store the data by column-wise with in the specific length.
suppose the i have to...
|
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,...
|
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: 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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