I'm porting a SQL Server based app to Oracle. Our Oracle DBA has given me a schema that was supposed to be identical to the original SQL Server schema (and generated from it), but the auto generated keys are missing. I am trying to alter these table PK's from a normal INT to incrementing. I am doing so with Oracle SQL Developer 4.0.3 and Oracle 12c.
The error I receive is ORA-01442: column to be modified to NOT NULL is already NOT NULL
I get this after editing the table, selecting the column and setting it's Identity dropdown to 'Generated as Identity'. I am not sure why SQl Developer is attempting to make it not null when it's already a PK.
My questions are: Is this the proper way to setup a generated key? How can I get around this? If I go alter all the required columns, can the DBA use the schema to regenerate whatever procedure he used to create it in the first place to allow proper generated keys and is there a better solution for creating a good schema to go forward with?
Thanks.
If the column is already definied as NOT NULL there is no need to re-defined it as NOT NULL. Therefore you get the error ora-01442.
The best way to obtain sequence values, such as identity in SQL Server, is define the column with default sequence, before inserting row:
CREATE SEQUENCE SEQ_NAME
START WITH 1
INCREMENT BY 1
NOCACHE
NOCYCLE;
ALTER TABLE table_name MODIFY column_name INT DEFAULT SEQ_NAME.NEXTVAL;
PD: This DEFAULT works with 12 c. To 11g or less, you must create a trigger
Related
I'm trying to alter my table named Vettura to modify field ID and making it both Primary and Auto increment, i have already looked in other answers on other similiar conversation, but i can't find the right answer, can you pls help me?
You might not be able to alter the table this way depending on what data is there and if there are dependencies.
If you are using SSMS, I would recommend scripting the database to an SQL file including both the schema and the data and setting DROP and CREATE. Then you can edit the table definition(s) and regenerate the database.
By the way, for SQL-Server, the Auto increment is called IDENTITY.
When I add a new record I want SQL Server to automatically add a fresh ID.
There are already some records which have been migrated over (from Access) and until I finish preparing the server for other required functionality I will be manually migrating further records over (if this affects any possible answers).
What are the simplest ways to implement this.
The simplest way would be to make the column an IDENTITY column. Here is an example of how to do this (it's not as simple as ALTER TABLE).
Make use of the Identity field type. This will automatically create a value for you using the next available number in the sequence.
Here is an example of how to create an Identity column (add a new column) on an existing table
ALTER TABLE MyTable ADD IdColumn INT IDENTITY(1,1)
I've got a new website moved to my server. This website uses PHP and MySQL, and is built very poorly.
The problem is - it needs non-null values inserted into new records where ever I don't specify a value, though the default value is null.
I've been told it has been done on the previous server, but they have no idea how. I'd be glad to receive some help on this.
You could update the default values of the fields of your database to prevent problems using:
ALTER TABLE `table` ALTER `field` SET DEFAULT 'value'
More information on ALTER TABLE for specific fields and parameters can be found in the documentation.
You need to add default values for the columns, either recreate the tables with defaults or alter the table definitions.
http://dev.mysql.com/doc/refman/5.1/en/alter-table.html
http://dev.mysql.com/doc/refman/5.1/en/create-table.html
I wanted to modify a column in a sql server 2005 table to IDENTITY(1,1)
Incidentally this table is empty and the column to be changed is a primary key.
This column is also a foreign key for two other tables.
After googling I found that you cannot use Alter table syntax to modify a column and make it an indentity column.
Link #1 : How do I add the identity property to an existing column in SQL Server
Link #2 : Adding an identity to an existing column -SQL Server
I ended up checking the dependent tables (2 of them) removing the foreign keys (generated the script from SSMS) then dropping the main table then re-creating with identity. (could try the rename option here as well)
Then re-created the foreign keys for the earlier dependent two tables.
But all this was manual work, any scripts or SPs out there to make this easier.
Ideally all these steps would be done by such a script/tool/utility:
Check dependent tables keys
Generate Create and drop foreign key scripts for this
Generate create script for the main table
drop the main table (or rename the table if the table has data)
re-create the table with identity column enabled
re-create foreign keys
You can use SSMS to generate a script (Edit a table, save script), but otherwise it's a manual process as you identified.
The SSMS scripts will pick up dependencies etc. For this kind of work, I tend to use SSMS to generate a basic script, pimp it a bit, run it carefully, then use a comparison tool (such as Red Gate compare) to generate a safer version.
Edit: The SSMS error is not an error, it's a safety check that can be switched off
(This is merely a follow-up to gbn's post with more details -- it isn't all that easy to figure this stuff out.)(
It isn't impossible to write a utility to do this, just very complex and very hard. Fortunately, Microsoft has already done it -- its called SSMS (or SMO?). To generate such a script:
In the Object Explorer, drill down to the database and table that you want to modify
Right click and select Design
Make the desired changes to the one table in the design screen. It's reasonably intuitive.
To add/remove the identity property, select the column in the upper pane, and in the lower pane/"Column Properties" tab, expand and configure the settings under "Identity Specification".
To generate a script to implement all your changes, incorporating all the dependent key changes, click on the "Generate Change Script" toolbar button. This is also an option under the "Table Designer" menu.
I also do this to generate scripts (that I later modify--SSMS doesn't always produce the most efficient code.) Once done, you can exit out without saving your changes -- leaving you a DB you can test your new script on.
drop the pk and build the same datatype column
copy the data of the column which you want to set identity to the new column.
drop the old column
reset primary key
ALTER TABLE UserRole
DROP CONSTRAINT PK_XX
ALTER TABLE XX
ADD newX int not null identity(1,1) primary key
update XX set newX = oldX
alter table XX
DROP COLUMN oldX
this is the simplest way to set identity column.
if you don't want to use the long generated script.
I'm trying to change the size of a column in sql server using:
ALTER TABLE [dbo].[Address]
ALTER COLUMN [Addr1] [nvarchar](80) NULL
where the length of Addr1 was originally 40.
It failed, raising this error:
The object 'Address_e' is dependent on column 'Addr1'.
ALTER TABLE ALTER COLUMN Addr1 failed because one or more objects access
this column.
I've tried to read up on it and it seems that because some views are referencing this column and it seems that SQL Server is actually trying to drop the column that raised the error.
Address_e is a view created by the previous DB Administrator.
Is there any other way I can change the size of the column?
ALTER TABLE [table_name] ALTER COLUMN [column_name] varchar(150)
The views are probably created using the WITH SCHEMABINDING option and this means they are explicitly wired up to prevent such changes. Looks like the schemabinding worked and prevented you from breaking those views, lucky day, heh? Contact your database administrator and ask him to do the change, after it asserts the impact on the database.
From MSDN:
SCHEMABINDING
Binds the view to the schema of the underlying table or tables. When
SCHEMABINDING is specified, the base
table or tables cannot be modified in
a way that would affect the view
definition. The view definition itself
must first be modified or dropped to
remove dependencies on the table that
is to be modified.
If anyone wants to "Increase the column width of the replicated table" in SQL Server 2008, then no need to change the property of "replicate_ddl=1". Simply follow below steps --
Open SSMS
Connect to Publisher database
run command -- ALTER TABLE [Table_Name] ALTER COLUMN [Column_Name] varchar(22)
It will increase the column width from varchar(x) to varchar(22) and same change you can see on subscriber (transaction got replicated). So no need to re-initialize the replication
Hope this will help all who are looking for it.
See this link
Resize or Modify a MS SQL Server Table Column with Default Constraint using T-SQL Commands
the solution for such a SQL Server problem is going to be
Dropping or disabling the DEFAULT Constraint on the table column.
Modifying the table column data type and/or data size.
Re-creating or enabling the default constraint back on the sql table column.
Bye
here is what works with the version of the program that I'm using: may work for you too.
I will just place the instruction and command that does it. class is the name of the table. you change it in the table its self with this method. not just the return on the search process.
view the table class
select * from class
change the length of the columns FacID (seen as "faci") and classnumber (seen as "classnu") to fit the whole labels.
alter table class modify facid varchar (5);
alter table class modify classnumber varchar(11);
view table again to see the difference
select * from class;
(run the command again to see the difference)
This changes the the actual table for good, but for better.
P.S. I made these instructions up as a note for the commands. This is not a test, but can help on one :)
Check the column collation. This script might change the collation to the table default. Add the current collation to the script.
You can change the size of the column in 3 steps:
Alter view Address_e and take in comment column /*Addr1*/
Run your script
ALTER TABLE [dbo].[Address]
ALTER COLUMN [Addr1] [nvarchar](80) NULL
Then again alter view Address_e, in order to uncomment column Addr1