I want to create an event than immediately register the user who created that event in an events attendance table. No field for the event is unique, except the primary key and this is assigned by the database. Is there anyway to get a row number or specific field from the last row affected by a non-query on an active database connection?
If you insert a record into a table that contains an AUTO_INCREMENT column, you can obtain the value stored into that column by calling the mysql_insert_id() function.
See the MySQL documentation for more info: 28.6.28.3 How to Get the Unique ID for the Last Inserted Row
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
I'm trying to insert a new row into a database which has four fields, the first is a primary key set as auto incrementing (integer) and the other three are strings.
I insert a new with the following statement:
INSERT INTO Manufacturer VALUES
('Test1','Test2','01332232321')
But I am given the following exception:
"SQLite error\r\ntable Manufacturer
has 4 columns but 3 values were
supplied"
I assumed that the primary key field can be omitted as the database would automatically assign and increment the value for me.
How would I go about fixing this? Is this a simple syntatical error or do I need to rethink my approach completely?
You have to specify columns:
INSERT INTO Manufacturer (col2, col3, col4) VALUES ('Test1','Test2','01332232321')
or pass the NULL value for primary key column.
I think you're looking for how to AUTOINCREMENT in sqllite
also How do I create an AUTOINCREMENT field
hello sir
In a Project of C# .net i have code to generate auto index, it it working fine. I have used logic as below;
1st count how many rows in table then retrieve what value has been stored in the table.
Then whatever the value it will be incremented by 1 for next field and hence it is next index.
There is problem occurs when index is more than 10. index in table is stored like this
1
10
11
2
3
4
5
6
7
8
9
so the last value in the table is 9 and next increment will produce 10, that is already
generated so it will be Primary key violation error.
So plz guide how to achieve auto index generation in my project.
Why dont you make the Column an Identity column like this
CREATE TABLE [dbo].[Foo](
[Foo] [int] IDENTITY(1,1) NOT NULL,
//Other columns
)
or alter if database already created
ALTER TABLE [dbo].[Foo](
[Foo] [int] IDENTITY(<Enter your last maximum number in the database>,1) NOT NULL,
//Other columns
)
Hope it helps
Instead of COUNTING ROWS, You need to get MAX value from table for that field/column, here as per given values it would be 11 and then increament it by +1.
So you need to use following query in your code,
Select Max(Key Field) + 1 from [table name]//this will give you new key value i.e. 12
I suggest you to use Identity column, so you don't have to worry about increamenting primary key values.
Check the datatype of your autoindex... I have a doubt it is treated as a string. First thing you need to do is define the datatype to integer. So far your seeding is ok.
Is there an easy way to add an ID (Identity(1,1) & PK) column to a table that already has data?
I have picked up a project that was freelanced out to a horrible developer that didn't put a PK, index or anything on the tables he made.
Now that I am LINQ-ifying it, I have no PK to insert or update off of.
ALTER TABLE MyTable ADD id INT IDENTITY(1,1) PRIMARY KEY CLUSTERED
I'd be tempted to do it in three stages -
Create a new table with all the same
columns, plus you primary key column
(script out the table and then alter
it to add a PK field)
Insert into the new table all of the
values from the old table
Once your happy with it, delete the
old table and rename your new one
with the Primary Key the same as the
old table.
Open up SQL Server Management Studio
Right click the table
Click Modify
Add the Column
Set the Properties ((Is Identity) Yes, Identity Seed 1, Identity Increment 1)
Right click the Column
Click Set Primary Key
Ctrl-S