Can a sql server table have two identity columns? - sql

I need to have one column as the primary key and another to auto increment an order number field. Is this possible?
EDIT: I think I'll just use a composite number as the order number. Thanks anyways.

CREATE TABLE [dbo].[Foo](
[FooId] [int] IDENTITY(1,1) NOT NULL,
[BarId] [int] IDENTITY(1,1) NOT NULL
)
returns
Msg 2744, Level 16, State 2, Line 1
Multiple identity columns specified for table 'Foo'. Only one identity column per table is allowed.
So, no, you can't have two identity columns. You can of course make the primary key not auto increment (identity).
Edit: msdn:CREATE TABLE (Transact-SQL) and CREATE TABLE (SQL Server 2000):
Only one identity column can be created per table.

You can use Sequence for second column with default value IF you use SQL Server 2012
--Create the Test schema
CREATE SCHEMA Test ;
GO
-- Create a sequence
CREATE SEQUENCE Test.SORT_ID_seq
START WITH 1
INCREMENT BY 1 ;
GO
-- Create a table
CREATE TABLE Test.Foo
(PK_ID int IDENTITY (1,1) PRIMARY KEY,
SORT_ID int not null DEFAULT (NEXT VALUE FOR Test.SORT_ID_seq));
GO
INSERT INTO Test.Foo VALUES ( DEFAULT )
INSERT INTO Test.Foo VALUES ( DEFAULT )
INSERT INTO Test.Foo VALUES ( DEFAULT )
SELECT * FROM Test.Foo
-- Cleanup
--DROP TABLE Test.Foo
--DROP SEQUENCE Test.SORT_ID_seq
--DROP SCHEMA Test
http://technet.microsoft.com/en-us/library/ff878058.aspx

Add one identity column and then add a computed column whose formula is the name of the identity column
Now both will increment at the same time

No it is not possible to have more than one identity column.
The Enterprise Manager does not even allow you to set > 1 column as identity. When a second column is made identity
Also note that ##identity returns the last identity value for the open connection which would be meaningless if more than one identity column was possible for a table.

create table #tblStudent
(
ID int primary key identity(1,1),
Number UNIQUEIDENTIFIER DEFAULT NEWID(),
Name nvarchar(50)
)
Two identity column is not possible but if you accept to use a unique identifier column then this code does the same job as well. And also you need an extra column - Name column- for inserting values.
Example usage:
insert into #tblStudent(Name) values('Ali')
select * from #tblStudent
Ps: NewID() function creates a unique value of type uniqueidentifier.

The primary key doesn't need to be an identity column.
You can't have two Identity columns.
You could get something close to what you want with a trigger...

in sql server it's not possible to have more than one column as identity.

I've just created a code that will allow you inserting two identities on the same table. let me share it with you in case it helps:
create trigger UpdateSecondTableIdentity
On TableName For INSERT
as
update TableName
set SecondIdentityColumn = 1000000+##IDENTITY
where ForstId = ##IDENTITY;
Thanks,

A workaround would be to create an INSERT Trigger that increments a counter.
So I have a table that has one identity col : applicationstatusid. its also the primary key.
I want to auto increment another col: applicationnumber
So this is the trigger I write.
create trigger [applicationstatus_insert] on [ApplicationStatus] after insert as
update [Applicationstatus]
set [Applicationstatus].applicationnumber =(applicationstatusid+ 4000000)
from [Applicationstatus]
inner join inserted on [applicationstatus].applicationstatusid = inserted.applicationstatusid

Related

SQL Server Insert with no specified columns

I have a table with an auto-generated ID column (and that's all!)
CREATE TABLE [dbo].[EmailGroup](
[EmailGroupGuid] [uniqueidentifier] NOT NULL
CONSTRAINT [PK_EmailGroup] PRIMARY KEY CLUSTERED ([EmailGroupGuid] ASC)
) ON [PRIMARY]
ALTER TABLE [dbo].[EmailGroup]
ADD CONSTRAINT [DF_EmailGroup_EmailGroupGuid] DEFAULT (newsequentialid()) FOR [EmailGroupGuid]
I want to INSERT into this table and extract the generated ID. but, I can't work out if it's possible. It seems to complain about the lack of values/columns.
DECLARE #Id TABLE (Id UNIQUEIDENTIFIER)
INSERT INTO EmailGroup
OUTPUT inserted.EmailGroupID INTO #Id
Is there any way to do this? I mean I could add a dummy column to the table and easily do this:
INSERT INTO EmailGroup (Dummy)
OUTPUT inserted.EmailGroupID INTO #Id
VALUES (1)
however I don't really want to.
I could also specify my own ID and insert that, but again, I don't really want to.
Though I'm not sure why would you need such a table, the answer to your question is to use the keyword DEFAULT:
INSERT INTO EmailGroup (EmailGroupGuid)
OUTPUT inserted.EmailGroupGuid INTO #Id
VALUES(DEFAULT);
Another option is to use DEFAULT VALUES, as shown in Pawan Kumar's answer.
The key difference between these two options is that specifying the columns list and using the keyword default gives you more control.
It doesn't seem much when the table have a single column, but if you will add columns to the table, and want to insert specific values to them, using default values will no longer be a valid option.
From Microsoft Docs on INSERT (Transact-SQL):
DEFAULT
Forces the Database Engine to load the default value defined for a column.
If a default does not exist for the column and the column allows null values, NULL is inserted.
For a column defined with the timestamp data type, the next timestamp value is inserted.
DEFAULT is not valid for an identity column.
DEFAULT VALUES
Forces the new row to contain the default values defined for each column.
So as you can see, default is column based, while default values is row based.
Please use this.
CREATE TABLE [dbo].[EmailGroup]
(
[EmailGroupGuid] [uniqueidentifier] NOT NULL CONSTRAINT [PK_EmailGroup] PRIMARY KEY CLUSTERED ([EmailGroupGuid] ASC)
) ON [PRIMARY]
ALTER TABLE [dbo].[EmailGroup]
ADD CONSTRAINT [DF_EmailGroup_EmailGroupGuid] DEFAULT (newsequentialid()) FOR [EmailGroupGuid]
DECLARE #Id TABLE (Id UNIQUEIDENTIFIER)
INSERT INTO EmailGroup
OUTPUT inserted.EmailGroupGuid INTO #Id DEFAULT VALUES
SELECT * FROM #Id
last 3 OUTPUTs from my Laptop
--92832040-7D52-E811-B049-68F728AE8695
--2B6ADC5F-7D52-E811-B049-68F728AE8695
--0140AF66-7D52-E811-B049-68F728AE8695

SQL Server Database unique number generation on any record insertion

I have like 11 columns in my database table and i am inserting data in 10 of them. i want to have a unique number like "1101 and so on" in the 11th column.
Any idea what should i do?? Thanks in advance.
SQL Server 2012 and above you can generate Sequence
Create SEQUENCE RandomSeq
start with 1001
increment by 1
Go
Insert into YourTable(Id,col1...)
Select NEXT VALUE FOR RandomSeq,col1....
or else you can use Identity
Identity(seed,increment)
You can start the seed from 1101 and increment the sequence by 1
Create table YourTable
(
id INT IDENTITY(1101,1),
Col varchar(10)
)
If you want to have that unique number in a different field then you can manipulate that field with primary key and insert that value.
If you want in primary key value, then open the table in design mode, go to 'Identity specification', set 'identity increment' and 'identity seed' as you want.
Alternatively you can use table script like,
CREATE TABLE Persons
(
ID int IDENTITY(12,1) PRIMARY KEY,
FName varchar(255) NOT NULL,
)
here the primary key will start seeding from 12 and seed value will be 1.
If you have your table definition already in place you can alter the column and add Computed column marked as persisted as:
ALTER TABLE tablename drop column column11;
ALTER TABLE tablename add column11 as '11'
+right('000000'+cast(ID as varchar(10)), 2) PERSISTED ;
--You can change the right operator value from 2 to any as per the requirements.
--Also replace ID with the identity column in your table.
create table inc
(
id int identity(1100,1),
somec char
)

Inserting a new column for serial number

I have table with 500 records in it and want to insert new column as "serial number" starting with 1.
If you care about the order in which the identity values are assigned, you are best off doing this:
CREATE TABLE dbo.NewTable
(
SerialNumber INT IDENTITY(1,1),
... other columns from original table ...
);
INSERT dbo.NewTable(...other columns...)
SELECT ...other columns...
FROM dbo.OriginalTable
ORDER BY ...ordering criteria...
OPTION (MAXDOP 1); -- to prevent parallelism from messing with identity
DROP TABLE dbo.OriginalTable;
EXEC sp_rename N'dbo.NewTable', N'OriginalTable', N'OBJECT';
You may have to deal with constraints etc. and you will want to do this in a transaction. The point is that just adding an identity column to the table with assign the identity values in an arbitrary order. If you don't care about how the existing values are assigned serial numbers, then just use Kyle's answer.
This could be achieved as follows:
alter table YourTable
add SrNo int identity(1,1)
in PostgreSQL just do:
ALTER TABLE ttaabbllee ADD COLUMN columnName serial NOT NULL; and done!..

Why is SQL server throwing this error: Cannot insert the value NULL into column 'id'?

I'm using the following query:
INSERT INTO role (name, created) VALUES ('Content Coordinator', GETDATE()), ('Content Viewer', GETDATE())
However, I'm not specifying the primary key (which is id). So my questions is, why is sql server coming back with this error:
Msg 515, Level 16, State 2, Line 1
Cannot insert the value NULL into column 'id', table 'CMT_DEV.dbo.role'; column does not allow nulls. INSERT fails.
The statement has been terminated.
I'm assuming that id is supposed to be an incrementing value.
You need to set this, or else if you have a non-nullable column, with no default value, if you provide no value it will error.
To set up auto-increment in SQL Server Management Studio:
Open your table in Design
Select your column and go to Column Properties
Under Indentity Specification, set (Is Identity)=Yes and Indentity Increment=1
use IDENTITY(1,1) while creating the table
eg
CREATE TABLE SAMPLE(
[Id] [int] IDENTITY(1,1) NOT NULL,
[Status] [smallint] NOT NULL,
CONSTRAINT [PK_SAMPLE] PRIMARY KEY CLUSTERED
(
[Id] ASC
)
)
If the id column has no default value, but has NOT NULL constraint, then you have to provide a value yourself
INSERT INTO dbo.role (id, name, created) VALUES ('something', 'Content Coordinator', GETDATE()), ('Content Viewer', GETDATE())
Encountered the same issue. This is something to do with your table creation. When you created table you have not indicate 'ID' column to be Auto Increment hence you get this error. By making the column Primary Key it cannot be null or contain duplicates hence without Auto Increment pretty obvious to throw column does not allow nulls. INSERT fails.
There are two ways you could fix this issue.
1). via MS SQL Server Management Studio
Got to MS SQL Server Management Studio
Locate your table and right click and select Design
Locate your column and go to Column Properties
Under Indentity Specification: set (Is Identity)=Yes and Indentity
Increment=1
2). via ALTER SQLs
ALTER TABLE table DROP COLUMN id; // drop the existing ID
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
You either need to specify an ID in the insert, or you need to configure the id column in the database to have Identity Specification = Yes.
As id is PK it MUST be unique and not null.
If you do not mention any field in the fields list for insert it'll be supposed to be null or default value.
Set identity (i.e. autoincrement) for this field if you do not want to set it manualy every time.
You need to set autoincrement property of id column to true when you create the table or you can alter your existing table to do this.
you didn't give a value for id. Try this :
INSERT INTO role (id, name, created) VALUES ('example1','Content Coordinator', GETDATE()), ('example2', 'Content Viewer', GETDATE())
Or you can set the auto increment on id field, if you need the id value added automatically.
I had a similar problem and upon looking into it, it was simply a field in the actual table missing id (id was empty/null) - meaning when you try to make the id field the primary key it will result in error because the table contains a row with null value for the primary key.
This could be the fix if you see a temp table associated with the error. I was using SQL Server Management Studio.
WARNING! Make sure the target table is locked when using this method
(As per #OnurOmer's comment)
if you can't or don't want to set the autoincrement property of the id, you can set value for the id for each row like this:
INSERT INTO role (id, name, created)
SELECT
(select max(id) from role) + ROW_NUMBER() OVER (ORDER BY name)
, name
, created
FROM (
VALUES
('Content Coordinator', GETDATE())
, ('Content Viewer', GETDATE())
) AS x(name, created)
RULE: You cannot IGNORE those colums that do not allow null values, when inserting new data.
Your Case
You're trying to insert values, while ignoring the id column, which does not allow nulls. Obviously this won't work.
Gladly for you the "Identity Specification" seems to automatically fill the not nullable id values for you (see selected answer), when you later execute the insert query.
My Case
The problem (while using SSMS): I was having this error when trying to add a new non-nullable column to an already existing table with data. The error I'd got was:
Cannot insert the value NULL into column 'id_foreign', table 'MyDataBase.dbo.Tmp_ThisTable'; column does not allow nulls. INSERT fails.
The statement has been terminated.
The solution:
I created the column I needed id_foreign, allowing nulls.
I edited/inserted all the required values for id_foreign.
Once the values where in place, I went back and unchecked the "Allow Nulls" checkbox. Now the error was gone.

Link a sequence with to an identity in hsqldb

In PostgreSql, one can define a sequence and use it as the primary key of a table. In HsqlDB, one can still accomplish creating an auto-increment identity column which doesn't link to any user defined sequence. Is it possible to use a user defined sequence as the generator of an auto-increment identity column in HsqlDB?
Sample sql in PostgreSql:
CREATE SEQUENCE seq_company_id START WITH 1;
CREATE TABLE company (
id bigint PRIMARY KEY DEFAULT nextval('seq_company_id'),
name varchar(128) NOT NULL CHECK (name <> '')
);
What's the equivalent in HsqlDB?
Thanks.
In version 2.0, there is no direct feature for this. You can define a BEFORE INSERT trigger on the table to do this:
CREATE TABLE company ( id bigint PRIMARY KEY, name varchar(128) NOT NULL CHECK (name <> '') );
CREATE TRIGGER trigg BEFORE INSERT
ON company REFERENCING NEW ROW AS newrow
FOR EACH ROW
SET newrow.id = NEXT VALUE FOR seq_company_id;
and insert without using any vlue for id
INSERT INTO company VALUES null, 'test'
Update for HSQLDB 2.1 and later: A feature has been added to support this.
CREATE SEQUENCE SEQU
CREATE TABLE company ( id bigint GENERATED BY DEFAULT AS SEQUENCE SEQU PRIMARY KEY, name varchar(128) NOT NULL CHECK (name <> '') );
See the Guide under CREATE TABLE http://hsqldb.org/doc/2.0/guide/databaseobjects-chapt.html#dbc_table_creation
In addition, 2.1 and later has a PostgreSQL compatibility mode in which it accepts the PostgreSQL CREATE TABLE statement that references the sequence in the DEFAULT clause and translates it to HSQLDB syntax.