Files
EasyGA/src/database/database.py

100 lines
2.5 KiB
Python

import sqlite3
from sqlite3 import Error
import os
class database:
"""Main database class that controls all the functionality for input /
out of the database."""
def __init__(self):
self.conn = None
def create_connection(self, db_file):
"""Create a database connection to the SQLite database
specified by db_file."""
conn = None
try:
conn = sqlite3.connect(db_file)
return conn
except Error as e:
print(e)
self.conn = conn
def create_table(self, create_table_sql):
"""Create a table from the create_table_sql statement."""
try:
c = self.conn.cursor()
c.execute(create_table_sql)
except Error as e:
print(e)
def insert_chromosome(self, generation, chromosome):
""" """
# Structure the insert data
db_chromosome = (generation, chromosome.fitness, '[chromosome]')
# Create sql query structure
sql = ''' INSERT INTO data(generation,fitness,chromosome)
VALUES(?,?,?) '''
cur = self.conn.cursor()
cur.execute(sql, db_chromosome)
self.conn.commit()
return cur.lastrowid
def insert_current_population(self, ga):
""" Insert current generations population """
# For each chromosome in the population
for chromosome in ga.population.chromosome_list:
# Insert the chromosome into the database
self.insert_chromosome(ga.current_generation, chromosome)
def create_data_table(self, ga):
"""Create the data table that store generation data."""
try:
# Remove old database file if it exists.
os.remove(ga.database_name)
except:
# If the database does not exist continue
pass
# create a database connection
self.conn = self.create_connection(ga.database_name)
# create tables
if self.conn is not None:
# create projects table
self.create_table(ga.sql_create_data_structure)
else:
print("Error! cannot create the database connection.")
def query_all(self, query):
"""Query for muliple rows of data"""
cur = self.conn.cursor()
cur.execute(query)
return cur.fetchall()
def query_one_item(self, query):
"""Query for single data point"""
cur = self.conn.cursor()
cur.execute(query)
query_data = cur.fetchone()
return query_data[0]