Perm Installation and Use
Perst is a Java database system, which is an embedded Object database. The following is a detailed introduction to the installation and usage process of Perst:
1. Download Perl: First, you need to download it from the official website of Perl（ http://www.mcobject.com/perst ）Download the installation files for Perl from. Choose the installation file that is suitable for your operating system, such as' perst-4.1. zip '.
2. Unzip installation files: Unzip the installation files to the directory of your choice.
3. Add Pest to the project: Add the JAR file of Pest to your project. You can find the JAR files in the extracted directory and add them to the classpath.
4. Create a database: Use the following code snippet to create a Perl database:
import org.garret.perst.*;
...
Storage db = StorageFactory.getInstance().createStorage();
db.open("myDatabase.dbs");
This will create a database file called 'myDatabase. dbs', and if the file does not exist, create a new database file.
5. Create a data table: Use the following code to create a data table:
import org.garret.perst.*;
...
db.beginThreadTransaction();
db.getRoot().add(new PersistentSet());
db.endThreadTransaction(TransactionMode.COMMIT);
This will create a data table called 'PersistentSet' in the database.
6. Data insertion: Use the following code to insert data into the data table:
import org.garret.perst.*;
...
PersistentSet set = (PersistentSet) db.getRoot().get(0);
set.add("Data to insert");
db.beginThreadTransaction();
db.getRoot().set(0, set);
db.endThreadTransaction(TransactionMode.COMMIT);
This will insert a data named 'Data to insert' in the 'PersistentSet' data table.
7. Data Query: Use the following code to query the data in the data table:
import org.garret.perst.*;
...
PersistentSet set = (PersistentSet) db.getRoot().get(0);
Object[] data = set.toArray();
for (Object obj : data) {
System.out.println(obj);
}
This will print out all the data in the data table.
8. Data modification: Use the following code to modify the data in the data table:
import org.garret.perst.*;
...
PersistentSet set = (PersistentSet) db.getRoot().get(0);
set.remove("Data to insert");
set.add("New data");
db.beginThreadTransaction();
db.getRoot().set(0, set);
db.endThreadTransaction(TransactionMode.COMMIT);
This will replace 'Data to insert' with 'New data'.
9. Data deletion: Use the following code to delete data from the data table:
import org.garret.perst.*;
...
PersistentSet set = (PersistentSet) db.getRoot().get(0);
set.remove("Data to delete");
db.beginThreadTransaction();
db.getRoot().set(0, set);
db.endThreadTransaction(TransactionMode.COMMIT);
This will delete 'Data to delete' from the data table.
The above is a detailed introduction to the installation and usage process of the Perl database, including database creation, data table creation, data insertion, modification, query, and deletion. According to your needs, you can perform more customized operations based on these sample codes.
