| |
by: Ken1 |
last post by:
I am going to drop a primary key from one column and create a new
column to be used as primary key in an existing database.
The old column was a date column which someone earlier though was a
good candidate for a primary key which we all know it's not.
Now I want to add a new field, i.e. called ID, with a normal number
sequence as primary key.
I have dropped the primary key, created the new column, created the
new sequence and created...
|
by: Richard Hollenbeck |
last post by:
I made a table this way:
mysql>create table tblCourses (courseCode char(30) primary key,
courseDescription char(50));
Now I realize that I forgot to enforce that both fields will not be null.
So I tried this:
mysql> alter table tblCourses (courseCode not null, courseDescription not
null);
|
by: M Simpson |
last post by:
/* for the google index */
ALTER TABLE
DEFAULT COLUMN
DEFAULT VALUE
I've worked out several stored procedures for altering the default column
values in a table. They were compiled from books and code snippets found
here. It was a pain to work out so I've decided to share my work and
research here. This post is just my way of saying thanks to several others
here for posting with their wisdom and intelligence.
|
by: Bruce |
last post by:
Hi,
I want to change the datatype of an existing column from char to
varbinary. When I run the "Alter Table" statement, I get the
following error message -
Disallowed implicit conversion from data type char to data type
varbinary, table 'test.dbo.testalter', column 'col1'. Use the CONVERT
function to run this query.
|
by: me |
last post by:
I would like to add an Identity to an existing column in a table using a
stored procedure then add records to the table and then remove the identity
after the records have been added or something similar.
here is a rough idea of what the stored procedure should do. (I do not know
the syntax to accomplish this can anyone help or explain this?
Thanks much,
CBL
|
| |
by: Brian Brane |
last post by:
I have properties that wrap DataRow columns as in:
public int aNumber
{ get{ return m_DataRow; }
set{ m_DataRow = value; } }
If the column happens to contain DBNull, I get a cast
exception since DBNull cannot be converted to int. I
wrote the following method that looks up the column's
data type and if it is a ValueType, returns the default
value for the ValueType.
|
by: Kimi |
last post by:
Hi,
I'm trying to change a column on a DB2 table so that it has a default value
but I cannot get it to work. Does anyone have any experience in this area.
I'm trying with this statement:
Alter Table x
Alter column y default 0;
|
by: spatik |
last post by:
Hi,
I have a tableevent] with a columnevent_description] as ntext and default value ''. Now, I want to change the column type to nvarchar(max) using this script,
alter table
alter column nvarchar(max) null ;
The event_description column was created with a default value ''.
Now this constraint is not allowing me to alter the column type. It throws an exception,
Msg 5074, Level 16, State 1, Line 1
|
by: pulavarthipraveen |
last post by:
When I tried to change the datatype of the column through
"Alter table tablename Alter column columnname Newdatatype" query
it's is throw the error below:
"The index 'IndexName' is dependent on column 'columnname'" .
But it allowed me to change the column datatype through Enterprise Manager Table Designer without any restictions.
1) What is the reason for having the difference between 2 appraches?
2) How we change through the query...
|
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 usage, and What is the difference between ONU and Router. Let’s take a closer look !
Part I. Meaning of...
|
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 synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
|
| |
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.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
|
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 captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
|
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 protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
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 instead of User Defined Types (UDT). For example, to manage the data in unbound forms.
Adolph will...
|
by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
|
by: adsilva |
last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
|
| |
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
|
3
