Berkeley DB

Adding Elements to a Database

The simplest way to add elements to a database is the DB→put interface, which takes five arguments:

• db: The database handle returned by db_create.

• txnid: A transaction handle. In our simple case, we aren’t expecting to recover the database after an application or system crash, so we aren’t using transactions and will leave this argument NULL.

• key: The key item for the key/data pair that we want to add to the database.

• data: The data item for the key/data pair that we want to add to the database.

• flags: Optional flags that modify the underlying behavior of the DB→put interface.

Here’s what the code to call DB→put looks like:

 #include <sys/types.h> #include <stdio.h> #include <db.h> #define DATABASE "access.db" ...