We have a tool and this tool create some insert scripts to add rows in our plsql table.
this scripts is not modifiable and we can't see this scripts. so,
when data row comes (with insert script that we don't know structure), we should give a primary key. we can use trigger but we don't want do this for reasons of performance.
Below code doesn't work.
CREATE TABLE qname
(
qname_id integer NOT NULL default qname_id_seq.nextval PRIMARY KEY,
);
Any idea?
Thanks..
.nextval cannot be used in Default Value of table, This is achieved by Trigger and Sequence when you want serialized number that anyone can easily read/remember/understand. But if you don't want to manage ID Column (like qname_id) by this way, and value of this column is not much considerable, you can use SYS_GUID() at Table Creation to get Auto Increment like this.
CREATE TABLE qname
(qname_id RAW(16) DEFAULT SYS_GUID() PRIMARY KEY,
name VARCHAR2(30));
(or by Modifying Column)
Now your qname_id column will accept "globally unique identifier value".
you can insert value in table by ignoring emp_id column like this.
INSERT INTO qname (name) VALUES ('name value');
So, it will insert unique value to your qname_id Column.
I am using SQL Server 2012 and need to add a column with a unique primary key. I am about to load several hundred thousand records BULK and just discovered repetition in the field I was going to use. Have seen SEQUENCE and GUID. Need some guidance on the best choice and how to go about setting this up so that the key field is populated during the bulk load.
When you create your table in which you want to insert information create an IDENTITY column. That will serve as an auto-populating column with a unique number for each record.
Here is a link that might help you.
If you have already created your table just change this query to what suits to your table name and run it in order to add the new column you requested.
ALTER TABLE mytable
ADD COLUMN unique_id IDENTITY (1,1)
Just a slight update on what’s already posted that includes details for adding primary key constraint
alter table database.schema.table_t
add ID_column int identity(1,1)
primary key (ID_column)
If you already set the primary key on this table just go and remove it before you execute this statement.
How do I auto increment the primary key in a SQL Server database table? I've had a look through the forum but can't see how to do this.
I've looked at the properties but can't see an option. I saw an answer where you go to the Identity specification property and set it to yes and set the Identity increment to 1, but that section is grayed out and I can't change the no to yes.
There must be a simple way to do this but I can't find it.
Make sure that the Key column's datatype is int and then setting identity manually, as image shows
Or just run this code
-- ID is the name of the [to be] identity column
ALTER TABLE [yourTable] DROP COLUMN ID
ALTER TABLE [yourTable] ADD ID INT IDENTITY(1,1)
the code will run, if ID is not the only column in the table
image reference fifo's
When you're creating the table, you can create an IDENTITY column as follows:
CREATE TABLE (
ID_column INT NOT NULL IDENTITY(1,1) PRIMARY KEY,
...
);
The IDENTITY property will auto-increment the column up from number 1. (Note that the data type of the column has to be an integer.) If you want to add this to an existing column, use an ALTER TABLE command.
Edit:
Tested a bit, and I can't find a way to change the Identity properties via the Column Properties window for various tables. I guess if you want to make a column an identity column, you HAVE to use an ALTER TABLE command.
You have to expand the Identity section to expose increment and seed.
Edit: I assumed that you'd have an integer datatype, not char(10). Which is reasonable I'd say and valid when I posted this answer
Expand your database, expand your table right click on your table and select design from dropdown.
Now go Column properties below of it scroll down and find Identity Specification, expand it and you will find Is Identity make it Yes. Now choose Identity Increment right below of it give the value you want to increment in it.
CREATE TABLE Persons (
Personid int IDENTITY(1,1) PRIMARY KEY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int
);
The MS SQL Server uses the IDENTITY keyword to perform an auto-increment feature.
In the example above, the starting value for IDENTITY is 1, and it will increment by 1 for each new record.
Tip: To specify that the "Personid" column should start at value 10 and increment by 5, change it to IDENTITY(10,5).
To insert a new record into the "Persons" table, we will NOT have to specify a value for the "Personid" column (a unique value will be added automatically):
Perhaps I'm missing something but why doesn't this work with the SEQUENCE object? Is this not what you're looking for?
Example:
CREATE SCHEMA blah.
GO
CREATE SEQUENCE blah.blahsequence
START WITH 1
INCREMENT BY 1
NO CYCLE;
CREATE TABLE blah.de_blah_blah
(numbers bigint PRIMARY KEY NOT NULL
......etc
When referencing the squence in say an INSERT command just use:
NEXT VALUE FOR blah.blahsequence
More information and options for SEQUENCE
When you're using Data Type: int you can select the row which you want to get autoincremented and go to the column properties tag. There you can set the identity to 'yes'. The starting value for autoincrement can also be edited there. Hope I could help ;)
I had this issue where I had already created the table and could not change it without dropping the table so what I did was:
(Not sure when they implemented this but had it in SQL 2016)
Right click on the table in the Object Explorer:
Script Table as > DROP And CREATE To > New Query Editor Window
Then do the edit to the script said by Josien; scroll to the bottom where the CREATE TABLE is, find your Primary Key and append IDENTITY(1,1) to the end before the comma. Run script.
The DROP and CREATE script was also helpful for me because of this issue. (Which the generated script handles.)
You can use the keyword IDENTITY as the data type to the column along with PRIMARY KEY constraint when creating the table.
ex:
StudentNumber IDENTITY(1,1) PRIMARY KEY
In here the first '1' means the starting value and the second '1' is the incrementing value.
If the table is already populated it is not possible to change a column to IDENTITY column or convert it to non IDENTITY column. You would need to export all the data out then you can change column type to IDENTITY or vice versa and then import data back.
I know it is painful process but I believe there is no alternative except for using sequence as mentioned in this post.
Be carefull like if you want the ID elements to be contigius or not. As SQLSERVER ID can jump by 1000 .
Examle: before restart ID=11
after restart , you insert new row in the table, then the id will be 1012.
You could do the following: New Table Creation:
-- create new table with Column ID which is Primary Key and Auto Increment --
CREATE TABLE titles(
id INT NOT NULL IDENTITY(1,1) PRIMARY KEY, --Primary Key with Auto-Increment --
keyword VARCHAR(260),
status VARCHAR(10),
);
If you Table Already exists and need to make the changes to ID column to be auto-increment and Primary key, then see below:
ALTER TABLE table DROP COLUMN id; // drop the existing ID in the table
ALTER TABLE table ADD id int IDENTITY(1, 1) NOT NULL; // add new column ID with auto-increment
ALTER TABLE table ADD CONSTRAINT PK_ident_test PRIMARY KEY CLUSTERED (id); // make it primary key
If I have a table with an identity column as the primary key, I would use scope_identity() to retrieve latest identity value inserted during scope. What if the primary key is not an identity column, but an nvarchar(256) with a default value of newid() to generate the value. After performing the insert, is there a function that I can use to retrieve that value and store it in some variable? I'll need to insert this value into other column ID's in other tables.
Here's an example of what I'm referring to. In the aspnet_Users table the userID is described like above, if I wanted to use the userID as a FK in my own table, would it be ok to use that autogenerated newid() value or is there a better way? If this is the best way how do I store it easily?
Thank you
The OUTPUT clause of the INSERT is what you are looking for. See this MSDN article.
basically:
DECLARE #newkey TABLE (keys varchar(25));
INSERT INTO actual_table (nonAutoIncId,other1,other2,other3)
OUTPUT INSERTED.nonAutoIncId INTO #newkey
VALUES ('NewId',1,2,3)
I am using Sql Server with Composite key. In this composite key contains one identity column i.e Auto incrment value. i want to generate in this column with duplicate values. How can i do this. Please give me a solution for this.
Thanks with Regards
Saravanan.M
The identity column cannot(corrected based on feedback from #AlexKuznetsov) should not have duplicates within the column itself - it is generally meant to be a unique column and a provide non-identifying value for each row.
If you are asking how to put values into the identity column that already exist in another column, you have to do the following:
Set IDENTITY_INSERT Schema.TableName ON
Insert Into TableName (PK1, PK2, IdentityCol1, OtherCol1, OtherCol2)
SELECT FirstCol, SecondCol, SecondCol, OtherColumn1, OtherColumn2
FROM SomeOtherTable
Set IDENTITY_INSERT Schema.TableName OFF
note that PK2 and IdentityCol1 both get the same value
It would be good if you could provide more context around what you are wanting to do and why? There are some good reasons to use composite keys, but if you're already using an identity field, why not make that your primary key?
Your auto-incrementing identity column should be left untouched and should continue to uniquely identify your rows. It is generally good practice to always have an abstract identity column as your primary key.
If you have 2 other values in your data model which uniquely identify your row, they should be in 2 other columns. If one of them is an auto-incrementing number then you can generate the value either in a stored proc which is used for all insertions or in an insert trigger.
Although this is not quite an answer, several answerers have made one and the same mistake, claiming that "You cant have an identity column with duplicates". In fact, identities may easily be not unique if you do not enforce their uniqueness by an index or constraint, as follows:
CREATE TABLE identityTest(i INT IDENTITY(1,1));
GO
INSERT identityTest DEFAULT VALUES;
INSERT identityTest DEFAULT VALUES;
SET IDENTITY_INSERT identityTest ON;
INSERT INTO identityTest(i)
SELECT i FROM identityTest;
SET IDENTITY_INSERT identityTest OFF;
SELECT i FROM identityTest;
i
-----------
1
2
1
2
GO
DROP TABLE identityTest;