using-auto-generated-keys.md

title	description	author	ms.author	ms.date	ms.service	ms.subservice	ms.topic
Using auto-generated keys	Learn how the JDBC Driver for SQL Server supports retrieving automatically generated row identifiers when an application performs database operations.	David-Engel	davidengel	08/12/2019	sql	connectivity	conceptual

Using auto-generated keys

[!INCLUDEDriver_JDBC_Download]

The [!INCLUDEjdbcNoVersion] supports the optional JDBC 3.0 APIs to retrieve automatically generated row identifiers. The main value of this feature is to provide a way to make IDENTITY values available to an application that is updating a database table without a requiring a query and a second round trip to the server.

Because [!INCLUDEssNoVersion] doesn't support pseudo columns for identifiers, updates that have to use the autogenerated key feature must operate against a table that contains an IDENTITY column. [!INCLUDEssNoVersion] allows only a single IDENTITY column per table. The result set that is returned by getGeneratedKeys method of the SQLServerStatement class will have only one column, with the returned column name of GENERATED_KEYS. If generated keys are requested on a table that has no IDENTITY column, the JDBC driver will return a null result set.

As an example, create the following table in the [!INCLUDEssSampleDBnormal] sample database:

CREATE TABLE TestTable
   (Col1 int IDENTITY,
    Col2 varchar(50),
    Col3 int);  

In the following example, an open connection to the [!INCLUDEssSampleDBnormal] sample database is passed in to the function, a SQL statement is constructed that will add data to the table, and then the statement is run and the IDENTITY column value is displayed.

[!codeJDBC#UsingAutoGeneratedKeys1]

See also

Using statements with the JDBC driver