I am troubleshooting a db (not my forte) that has some tables that are auto incrementing on the id column and some tables are not?
Now all the tables are set as identity and marked to disallow null. I am using SSMS what else can I check or do to get these tables back to auto incrementing?
TIA
Interestingly to me...probably old news to you guys. The issue had to do with existing data. So for example a table that had 100 rows in did NOT have the identity column setup. So I would go in and make it an identity with a seed of 1 incrementing 1. Well the seed was somehow having trouble because there was already 100 rows in there. So for all my tables I had to do a row count and seed the identity from the next row. Now it is working as expected.
Having an IDENTITY column is pretty straightforward for a table, and if you are not seeing the auto incrementing behavior of a column on inserts, then I'd first verify that your column is indeed an IDENTITY column:
use <Your Database Name>;
go
select
name,
is_identity
from sys.columns
where object_id = object_id('<Your Table Name>')
order by column_id;
Substitute <Your Database Nam> and <Your Table Name> for their appropriate values.
The other possibility is that data that "appears" to be non-incrementing could have been pushed out to that with a session that set identity insert and pushed out explicit values.
ALTER TABLE YourTable MODIFY COLUMN YourTable_id int(4) auto_increment
Related
I have set some script that inserts data from an XML file into a SQL database. I am getting the following error.
Cannot insert the value NULL into column 'fighterID', table 'MMA Database.dbo.FIGHTERStemp'; column does not allow nulls. INSERT fails.
I have fighterID set as the primary key and will not allow NULLS. My intention is to have it number each row as they are inserted. I found one answer that advises to modify the column properties to be the identifier. However it will not let me adjust the columns properties without dropping and adding the table again.
I can do that - but what is the SQL syntax to set the identity specification settings? Am I going about this the right way?
It's pretty simple, just set the field with datatype INT (integer) and follow it with keyword IDENTITY. You can include the seed and increment values; e.g. start at 1, increment by 1, or just use the keyword IDENTITY for a 1,1 default.
CREATE TABLE MMA (FighterID INT IDENTITY (1,1), FighterInfo VARCHAR(MAX))
While inserting data into Primary key you can check the previous max id value and then increment it to next value before you insert a new row.
In SQL, you need to drop table before altering its specification. You can do this by taking backup into temp table then drop your main table and then re insert data from temp table.
I've already read the following answers about the impossibility to alter a column into identity once has been created as a regular int.
Adding an identity to an existing column
How to Alter a table for Identity Specification is identity SQL Server
How to alter column to identity(1,1)
But the thing is I have a table which has been migrated to a new one where the ID was not declared as identity from the beginning, because the old table which was created with an ID identity a long time ago has missing rows due to a purge of historical data. So as far as I know, if I add a new column as identity on my new table, it will automatically create the column sequentially and I need to preserve the IDs from the old table as-is because there is already data linked to these previous IDs.
How can I do transform my ID column from the new table as identity but not sequentially, but with the IDs from the old table?
You could try this approach:
Insert rows with old ID with SET IDENTITY_INSERT <new table> ON. This allows you to insert your own ID.
Reseed the Identity, setting it to the highest ID value +1 with DBCC CHECKIDENT ('<new table>', RESEED, <max ID + 1>). This will allow your Identity to increase from the highest ID and forward.
Something like this in code:
-- Disable auto increment
SET IDENTITY_INSERT <new table> ON
-- <INSERT STUFF HERE>
SET IDENTITY_INSERT <new table> OFF
-- Reseed Identity from max ID
DECLARE #maxval Int
SET #maxval = ISNULL(
(
SELECT
MAX(<identity column>) + 1
FROM <new table>
), 0)
DBCC CHECKIDENT ('<new table>', RESEED, #maxval)
EDIT: This approach requires your ID-column to be an Identity, of course.
If you don't have nulls in the field that you want to copy over from your previous version, you could first figure out what the largest ID is by just doing a max(Id) select. Then using SSMS go add your new field and when you set it as identity, just set the SEED value to something higher than what your current max is so you don't have collisions on new inserts.
I have a process where a temp table is used between a source file, CSV and the production table. The temp table has to match the CSV file columns, there is no PK in this data.
To find a set of rows before and after where the Azure Data Factory was failing, I imported over 2,000,000 rows into a temp table. The process stopped in Azure at 1,500,000 rows.
The error was that an integer or string would be truncated.
This line of code added a PK to the temp table and incremented it:
ALTER TABLE ##FLATFILETEMPBDI ADD ROWNUM INT IDENTITY
That would be the simplest solution to get a row number. I was then able to do this query to find the rows just before and after 1,500,000:
SELECT
ROWNUM
, PARTDESCRIPTION
, LEN(PARTDESCRIPTION) AS LENDESCR
, QUANTITY
, ONORDER
, PRICE
, MANUFACTURERPARTNUMBER
FROM ##FLATFILETEMPBDI
WHERE ROWNUM BETWEEN 1499990 AND 1500005
Works perfectly -- was not planning on it to be that easy, was surprised as anyone to see that the ALTER TABLE with IDENTITY worked to do the numbering for me.
I have a table filled with data and one of the columns - TrackingNumber - is an integer value. I have gotten a request to change it to auto-increment and to have it start the identity seed at 1000000. I know that I cannot alter a column to be an identity column in an existing table with data, so I have two options: either create an entirely new table and then move data from the old table into that new table or add an new identity column and update it with data from the old column.
The problem is that I need to retain all the existing values in column TrackingNumber. I have tried the following:
1) ALTER TABLE [dbo].[Table1]
ADD [TrackingNumber2] [bigint] IDENTITY (1000000, 1) NOT NULL
2) UPDATE [dbo].[Table1]
SET [TrackingNumber2]=[TrackingNumber]
3) ALTER TABLE [dbo].[Table1]
DROP COLUMN [TrackingNumber]
GO
4) EXEC sp_rename 'Table1.TrackingNumber2', 'TrackingNumber','COLUMN'
I got an error on step 2 - Updating new column with the value from the old column: "Cannot update identity column 'TrackingNumber2'"
Can anyone recommend a workaround?
You just need to set identity_insert on for this table so you can update the values. Make sure you turn it back off when you complete the update. :)
https://msdn.microsoft.com/en-us/library/ms188059.aspx
Are you sure you need to use an identity column? There are alternatives. For example, since SQL Server 2012 (and azure, too), there are these things called sequences. You can define a sequence to start at any number you like:
create sequence dbo.TrackingSequence
as int
start with 1000000
increment by 1
no maxvalue
no cycle
no cache
Then, you can alter the table such that the default value for the column in question defaults from the sequence:
alter table dbo.MyTable
add constraint [MyTable.TrackingNumber.Default.TrackingSequence]
default( next value for dbo.TrackingSequence ) for TrackingNumber
(If the column already has a default value, you need to remove that first - in a separate statement.)
A sequence works a lot like an identity, but you don't have to disrupt existing values or the column definition per se.
The only trick is to remember to not specify the value for TrackingNumber, and let the DB do its thing.
Sequences are cool in that you can have one sequence that is used by multiple tables, giving you somewhat shorter db-wide unique IDs than alternatives in the past. For such an application, you'd probably be better off with a bigint column - or know that the tables in question aren't going to be terribly long.
I ended up creating a new table and moving data in there
Is there any way of changing the identity seed for an identity column permanently? Using DBCC CHECKIDENT just seems to set the last_value. If the table is truncated all values are reset.
dbcc checkident ('__Test_SeedIdent', reseed, 1000)
select name, seed_value, increment_value, last_value
from sys.identity_columns
where [object_id] = OBJECT_ID('__Test_SeedIdent');
returns
name seed_value increment_value last_value
-------------------------------------------------
idIdent 1 1 1000
I was hoping that some syntax like
alter table dbo.__Test_SeedIdent alter column idIdent [int] identity(1000,1) NOT NULL
would exist.
Is it necessary to create a new column, move the values across, drop the original column and rename the new?
From Books Online:
"To change the original seed value and reseed any existing rows, you must drop the identity column and recreate it specifying the new seed value. When the table contains data, the identity numbers are added to the existing rows with the specified seed and increment values. The order in which the rows are updated is not guaranteed."
MSSQL does not allow you to add or alter an Identity on an existing column via TSQL very easily. You would have to drop the column and re-add it. Needless to say this can play hell with FK relations. You can do it directly in the enterprise manager. However that won't be fun if you have to do this to a LOT of columns.
Is it necessary to create a new
column, move the values across, drop
the original column and rename the
new?
Yup, and don't forget to fix/update all indexes, foreign key relationships, etc. that are tied to that column
You can use DBCC CHECKIDENT('tablename', RESEED, seedvalue)
example: DBCC CHECKIDENT('Customers',RESEED, 1350)
run DBCC CHECKIDENT('Customers') again to check if current seed value was set.
However as mentioned in previous answers this will not change existing values stored in the identity column. It will only change seed value so the next row that is inserted will start with that value. Identity increment remains same (not changed) and can not be changed with DBCC.
"Is it necessary to create a new column, move the values across, drop the original column and rename the new?"
Actually in Enterprise Manager, when you add an ID column to an existing table (or change an INT PK field to an INT PK ID), it does this behind the scene.
Is there a way to reserve or skip or increment value of identity column?
I Have two tables joined in one-to-one relation ship. First one has IDENTITY PK column, and second one int PK (not IDENTITY). I used to insert in first, get ID and insert in second. And it works ok.
Now I need to insert values in second table without inserting into first.
Now, how to increment IDENTITY seed, so I can insert it into second table, but leave "hole" in ID's of first table?
EDIT: More info
This works:
-- I need new seed number, but not table row
-- so i will insert foo row, get id, and delete it
INSERT INTO TABLE1 (SomeRequiredField) VALUES ('foo');
SET #NewID = SCOPE_IDENTITY();
DELETE FROM TABLE1 WHERE ID=#NewID;
-- Then I can insert in TABLE2
INSERT INTO (ID, Field, Field) VALUES (#NewID, 'Value', 'Value');
Once again - this works.
Question is can I get ID without inserting into table?
DBCC needs owner rights; is there a clean user callable SQL to do that?
This situation will make your overall data structure very hard to understand. If there is not a relationship between the values, then break the relationship.
There are ways to get around this to do what you are looking for, but typically it is in a distributed environment and not done because of what appears to be a data model change.
Then its no more a one-to-one relationship.
Just break the PK constraint.
Use a DBCC CHECKIDENT statement.
This article from SQL Server Books Online discusses the use of the DBCC CHECKIDENT method to update the identity seed of a table.
From that article:
This example forces the current identity value in the jobs table to a value of 30.
USE pubs
GO
DBCC CHECKIDENT (jobs, RESEED, 30)
GO
I would look into the OUTPUT INTO feature if you are using SQL Server 2005 or greater. This would allow you to insert into your primary table, and take the IDs assigned at that time to create rows in the secondary table.
I am assuming that there is a foreign key constraint enforced - because that would be the only reason you would need to do this in the first place.
How do you plan on matching them up later? I would not put records into the second table without a record in the first, that is why it is set up in a foreign key relationship - to stio that sort of action. Just why do you not want to insert records into the first table anyway? If we knew more about the type of application and why this is necessary we might be able to guide you to a solution.
this might help
SET IDENTITY_INSERT [ database_name . [ schema_name ] . ] table { ON | OFF }
http://msdn.microsoft.com/en-us/library/aa259221(SQL.80).aspx
It allows explicit values to be inserted into the identity column of a table.