Somehow, my table messed up the Auto Increment value and it's giving me a duplicate key on insert with auto-increment ID. How do I set the Auto-Increment value in Access 2007?
Figure it out:
ALTER TABLE Table ALTER COLUMN Field COUNTER(1000,1)
Related
I'm new to SQL. I created a table and filled it with some data. Now I want to change the properties of my primary key, so it will auto increment every single time by itself when adding data.
I know how to do it when creating a table, but where do I add auto_increment now, when I already have a created table with filled data?
Update
Try
ALTER TABLE [TableName] DROP COLUMN ID
ALTER TABLE [TableName] ADD ID INT IDENTITY(1,1)
If you had entered data to your table review this link that have an answer to you question SQL Server, How to set auto increment after creating a table without data loss?
You can't change logical structure column when you have some filled data in column. That's impossible. You must deleting data from column and use ALTER TABLE to change properites column
Is there any way to simply add not null unique column to existing table. Something like default = 1++ ? Or simply add unique column?
I tried to add column and then put unique contrain but MS SQL says that:
The CREATE UNIQUE INDEX statement terminated because a duplicate key was found for the object name (...) The duplicate key value is ( < NULL > ).
Any way to simply add column to existing working table with unique constrain? Should MS SQL really think that null IS a value?
Add not null column with some default.
Update column to be a sequential integers (see row_number() function)
Add UNIQUE constraint or UNIQUE index over new column
You can add IDENTITY column to a table (but from question it is not clear if you need it or not).
IDENTITY is all you need:
ALTER TABLE TestTable
ADD ID INT IDENTITY(1, 1)
If you want an autonumber, you can add an identity.
If you need to populate the values yourself, you add the column allowing nulls, update the values, check to make sure they are unique and that there are no nulls, then add the unique constraint and trhe not null property. It is best to do this during a maintenance window when no one else would be changing data in that table.
I have created a table in SQL Server 2012 with primary key as auto increment. But how can I remove that auto increment property from the table using a SQL query?
If you need to keep the data in that column then create a new column on the table which is of the same type (but a different name), copy the data from the column you want to get rid of to the new one, drop the old column and rename the new. Complete example:
CREATE TABLE test(col1 INT IDENTITY (1,1) NOT NULL, col2 VARCHAR(10) NULL);
ALTER TABLE test ADD col3 INT NULL;
UPDATE test SET col3 = col1;
ALTER TABLE test DROP COLUMN col1;
EXEC sp_rename 'dbo.test.col3', 'col1', 'COLUMN';
The easiest way would be:
Open SQL Server Management Studio.
Locate Server > DataBase > Table.
Right Click on the Table > Select Design.
In the design window, Highlight the column you want to modify.
In the Column Properties Window browse to Identity Specification > Is Identity And set to No.
Go to the toolbar menu > Table Designer > Select Generate Change Script...
Walla, you got the requested script.
I Like using this method for getting scripts, since it allows me to generate scripts I'm not sure how to compose from scratch and thus learning and improving my skills...
If it's a primary key column, then you have to drop the PK first. If there's any tables referencing it, then you'll have to drop these FKs to be able to drop the PK. After that, add another column of the same type, update it with values from identity column, drop the identity column, rename the new column to whatever the name of identity column was (with sp_rename procedure), recreate the PK, recreate the FKs, check if everything went right.
I'd be very careful doing it on a production database. Ensure that noone can access the data while you're doing this.
I searched a lot to find a simple solution to remove the auto increment because i should do a lot of work if i drop the column and the primary key which was a foreign key on another table where I should remove the data that are using my foreign ... finally I ended up with a very simple solution that made my life easy:
SET IDENTITY_INSERT <table_name> ON ;
SET IDENTITY_INSERT [TABLE] OFF .. this allows to remove the auto increment to off state.., so that we have to enter the value in thatcolumn
I have an existing table where I use existing column (type INT) as PK and manually increment its value with each row inserted. I wanted to change it to IDENTITY with auto increment. I found a thread here (http://stackoverflow.com/questions/4862385/sql-server-add-auto-increment-primary-key-to-existing-table) that seems to achieve exactly what I want. But every time I run the ALTER statement, Mgmt Studio crashes.
I had also tried to achieve my above goal by changing the column properties manually (Identity specification/Is Identity:yes) as in this thread (http://stackoverflow.com/questions/3876785/sql-server-cant-insert-null-into-primary-key-field). But every time I close the table after changing properties, I get an error
'Pix' table
Unable to modify table.
Cannot insert the value NULL into column 'picID', table 'photo.dbo.Tmp_Pix'; column does not allow nulls. INSERT fails.
The statement has been terminated.
Not sure what's going on.
You cannot change an existing column to become an IDENTITY column.
What you need to do is:
create a new column with INT IDENTITY
drop the primary key constraint
drop the old column
add the primary key constraint on the new column
The trouble might be - if you already have data in that table - that the new identity values don't necessarily match the old values in your manual ID column.
If you need to preserve those, then it gets even more involved:
create a new table with the proper structure, and make sure that the ID column is INT IDENTITY
turn on IDENTITY_INSERT for that table
insert all the rows from the old table into the new one (and in the process, insert the old ID values into the new ID IDENTITY column)
turn off IDENTITY_INSERT for that table
drop the old table
possibly rename the new table
In my table I want to have an ID column that is going to be unique and it is going to be autoincremented. I want to start from 0.
How can I implement it?
Basically, create a column of type INTEGER PRIMARY KEY or a column called ROWID, then don't specify the value when inserting a row.
Full details are on the SQLite page on Autoincrement.