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96 lines
2.6 KiB
Markdown
96 lines
2.6 KiB
Markdown
1 year ago
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---
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title: "Aplicacion web Oracle"
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date: 2022-10-30T17:08:54+01:00
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draft: false
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---
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Aplicación web Oracle programada en python.
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## Preparación
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Antes de crear el fichero que va a ser la aplicación, vamos a crear un **Entorno virtual** (Venv) de python para contener ahí los módulos que nos descarguemos
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```bash
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mkdir aplicacion_web_oracle && cd aplicacion_web_oracle
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python3 -m venv /home/roberto/aplicacion_web_oracle
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source bin/activate
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```
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Ahora vamos a descargar los módulos necesarios:
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```bash
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pip install cx_oracle
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pip install flask
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```
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Ahora, usando **flask**, se ha escrito la siguiente aplicación sencilla, que permite, al introducirle el nombre de un empleado en la dirección `/emp/`, mostrar los datos de dicho empleado. Es importante que, cuando se define **pool** se introduzcan los mismo datos que en el acceso remoto a oracle, ya que esta aplicación se ha creado desde una máquina distina a la de oracle.
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```python
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import os
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import sys
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import cx_Oracle
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from flask import Flask
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def init_session(connection, requestedTag_ignored):
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cursor = connection.cursor()
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cursor.execute("""
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ALTER SESSION SET
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TIME_ZONE = 'UTC'
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NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI'""")
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# start_pool(): starts the connection pool
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def start_pool():
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pool_min = 4
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pool_max = 4
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pool_inc = 0
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pool_gmd = cx_Oracle.SPOOL_ATTRVAL_WAIT
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print("Connecting to", "192.168.122.105:1521/ORCLCDB")
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pool = cx_Oracle.SessionPool(user="roberto",
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password="roberto",
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dsn="192.168.122.105:1521/ORCLCDB",
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min=pool_min,
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max=pool_max,
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increment=pool_inc,
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threaded=True,
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getmode=pool_gmd,
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sessionCallback=init_session)
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return pool
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app = Flask(__name__)
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@app.route('/')
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def index():
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return "Entra en /emp/nombreempleado para ver los datos del empleado"
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# Show the username for a given id
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@app.route('/emp/<string:name>')
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def show_username(name):
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connection = pool.acquire()
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cursor = connection.cursor()
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cursor.execute("select * from emp where ename = (:name)", [name])
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r = cursor.fetchone()
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r = str(r)
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return (r)
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################################################################################
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#
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# Initialization is done once at startup time
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#
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if __name__ == '__main__':
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# Start a pool of connections
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pool = start_pool()
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# Start a webserver
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app.run(port=int(os.environ.get('PORT', '8080')))
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```
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