Using Python to Operate VelocityDB
VelocityDB is a high-performance Object database, which can be used to store and manage a large amount of object data. Using Python to operate a VelocityDB database requires installing the VelocityDB Python library.
The following are the steps to operate the VelocityDB database using Python:
1. Install the VelocityDB Python library:
-Open a command prompt or terminal window.
-Run the following command: ` pip install VelocityDB`
2. Connect to the VelocityDB database:
python
from VelocityDB.session import Session
#Create database session
session = Session.open("path_to_database", readOnly=False)
#Create or get Object database
database = session.database("database_name", create=True)
3. Insert data:
python
from VelocityDB.odb import ODB
from VelocityDB.typeInfo import PType
from VelocityDB.object import ObjectInstantiator
#Creating an Object Instantiator
instantiator = ObjectInstantiator(database)
#Create a Object database
odb = ODB(instantiator)
#Define a class
class Person(PType):
def __init__(self, name, age):
super().__init__()
self.name = name
self.age = age
#Create a Person object instance in the Object database
person = Person("John Doe", 30)
odb.store(person)
#Submit Changes
odb.commit()
4. Query data:
python
#Retrieve Person object instances
person = odb.queryByExample(Person).getAny()
#Print Data
print(person.name)
print(person.age)
5. Modify data:
python
#Modifying the Properties of a Person Object Instance
person.age = 31
#Submit Changes
odb.commit()
6. Delete data:
python
#Delete Person object instance
odb.delete(person)
#Submit Changes
odb.commit()
Complete Python code example:
python
from VelocityDB.session import Session
from VelocityDB.odb import ODB
from VelocityDB.typeInfo import PType
from VelocityDB.object import ObjectInstantiator
#Create database session
session = Session.open("path_to_database", readOnly=False)
#Create or get Object database
database = session.database("database_name", create=True)
#Creating an Object Instantiator
instantiator = ObjectInstantiator(database)
#Create a Object database
odb = ODB(instantiator)
#Define a class
class Person(PType):
def __init__(self, name, age):
super().__init__()
self.name = name
self.age = age
#Create a Person object instance in the Object database
person = Person("John Doe", 30)
odb.store(person)
#Submit Changes
odb.commit()
#Retrieve Person object instances
person = odb.queryByExample(Person).getAny()
#Print Data
print(person.name)
print(person.age)
#Modifying the Properties of a Person Object Instance
person.age = 31
#Submit Changes
odb.commit()
#Delete Person object instance
odb.delete(person)
#Submit Changes
odb.commit()
Please replace 'path_to_database' with the path of the VelocityDB database file according to the actual situation, and modify 'databasename' and other relevant information as needed.