Lindorm:Use DBUtils to develop applications

Preparations

Run the following code to install phoenixdb V1.2.0 and DBUtils V3.0.2:

pip install phoenixdb==1.2.0
pip install DBUtils==3.0.2

Sample code

#!/usr/bin/python3

from dbutils.pooled_db import PooledDB
import importlib


class DBUtilsDemo:

    def __init__(self, url, user, password, database):
        config = {
            'url': url,
            'lindorm_user': user,
            'lindorm_password': password,
            'database': database,
            'autocommit': True
        }
        db_creator = importlib.import_module("phoenixdb")
        # Create a connection pool based on DBUtils.
        self.pooled = PooledDB(db_creator,
                               maxcached=10,
                               # Specify the maximum number of idle connections in the connection pool based on business requirements.
                               maxconnections=50,
                               # Specify the maximum number of connections in the connection pool based on business requirements.
                               blocking=True,
                               # Specify whether the client waits if no idle connection is available in the connection pool. True indicates that the client waits until a connection is available. False indicates that the client does not wait for an idle connection. 
                               ping=1,
                               # Check whether the server can be accessed.
                               **config)

    # Obtain a connection from the connection pool.
    def _connect(self):
        try:
            r = self.pooled.connection()
            return r
        except Exception as e:
            print("Failed to connect:" + str(e))

    # Return a connection to the connection pool.
    def _close(self, conn, stmt):
        if stmt:
            stmt.close()
        if conn:
            conn.close()

    # Query a single row of data.
    def select_row(self, sql):
        connection = self._connect()
        statement = None
        try:
            statement = connection.cursor()
            statement.execute(sql)
            row = statement.fetchone()
            return row
        except Exception as e:
            print(e)
        finally:
            self._close(connection, statement)

    # Query multiple rows of data.
    def select_rows(self, sql):
        connection = self._connect()
        statement = None
        try:
            statement = connection.cursor()
            print(sql)
            statement.execute(sql)
            rows = statement.fetchall()
            return rows
        except Exception as e:
            print(e)
        finally:
            self._close(connection, statement)

    # Update and insert data to a table.
    def upsert_data(self, sql_upsert):
        connection = self._connect()
        statement = None
        try:
            statement = connection.cursor()
            statement.execute(sql_upsert)
            connection.commit()
        except Exception as e:
            print(e)
        finally:
            self._close(connection, statement)

    # Update and insert data to a table by specifying parameters.
    def upsert_data_prams(self, sql_upsert, prams):
        connection = self._connect()
        statement = None
        try:
            statement = connection.cursor()
            statement.execute(sql_upsert, prams)
            connection.commit()
        except Exception as e:
            print(e)
        finally:
            self._close(connection, statement)

if __name__ == '__main__':
    # Specify the endpoint that is used to connecte to LindormTable by using SQL. 
    url = 'http://ld-bp1p7e07ohamf****-proxy-lindorm-pub.lindorm.rds.aliyuncs.com:30060'
    # Specify the actual username used to connect to LindormTable. You can view the username and password used to connect to LindormTable in the LindormTable cluster management system. 
    user = 'root'
    # Specify the actual password used to connect to LindormTable.
    password = 'root'
    # Specify the name of the database to which you want to connect.
    database = 'test'

    poolUtils = DBUtilsDemo(url, user, password, database)
    poolUtils.upsert_data("upsert into tb(id,name,address) values ('i001','n001','a001')")

    params = ['i002', 'n002', 'a002']
    poolUtils.upsert_data_prams("upsert into tb(id,name,address) values (?,?,?)", params)

    rows = poolUtils.select_rows("select * from tb")
    print(rows)

    row = poolUtils.select_row("select * from tb limit 1")
    print(row)

    row = poolUtils.select_row("select * from tb where id = 'i001' limit 1")
    print(row)