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Table of Contents
In Berkeley DB, a database is a collection of records. Records, in turn, consist of key/data pairings.
Conceptually, you can think of a Database as containing a two-column table where column 1 contains a key and column 2 contains data. Both the key and the data are managed using DatabaseEntry class instances (see Database Records for details on this class ). So, fundamentally, using a DB Database involves putting, getting, and deleting database records, which in turns involves efficiently managing information encapsulated by DatabaseEntry objects. The next several chapters of this book are dedicated to those activities.
You open a database by instantiating a Database object.
Note that by default, DB does not create databases if they do not already exist. To override this behavior, set the creation property to true.
The following code fragment illustrates a database open:
package db.GettingStarted;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.Database;
import com.sleepycat.db.DatabaseConfig;
import java.io.FileNotFoundException;
...
Database myDatabase = null;
...
try {
// Open the database. Create it if it does not already exist.
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setAllowCreate(true);
myDatabase = new Database ("sampleDatabase.db",
null,
dbConfig);
} catch (DatabaseException dbe) {
// Exception handling goes here
} catch (FileNotFoundException fnfe) {
// Exception handling goes here
}