Hello i'm trying to get a mysql database connection with jython.
I'm using Python 3.3.2 and Jython 2.5.3
My code looks like this:
import sys
from java.sql import *
sys.path.append("C:\\dev\\git\\LogAnalysis\\mysql-connector-java-5.0.8.jar")
con = DriveManager.getConnection("jdbc:mysql://localhost:3306/statistik", "root", "admin")
stmt = con.createStatement()
rs = stmt.executeQuery("SELECT * FROM search")
and so on. (Only a code snippet)
Each time i get the exeption:
java.sql.SQLException: java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/statistik
Can someone give me a tip?
See solution at: Jython CLASSPATH, sys.path and JDBC drivers
For me the easiest solution is to provide batch/shell script which sets CLASSPATH. This looks like:
SET CLASSPATH=C:\dev\git\LogAnalysis\mysql-connector-java-5.0.8.jar;%CLASSPATH%
CALL jython your_program.py %1 ...
Then you can remove line with:
sys.path.append(...)
Related
I am trying to connect pandas to Oracle as below(I already downloaded oracle client):
import pandas as pd
import cx_Oracle
username='a'
password='d'
host_name = 'aa.com'
service_name= 'ss'
dsn = cx_Oracle.makedsn(host=host_name,port=1535,sid=None,service_name=service_name)
con = cx_Oracle.connect(user=username, password=password, dsn= dsn ,encoding = "UTF-8", nencoding = "UTF-8")
my_sql_query=(""" SELECT * FROM schema.tbl1 WHERE ROWNUM =1 """)
##1- Directly reading SQL to Pandas
#Read SQL via Oracle connection to Pandas DataFrame
df = pd.read_sql(my_sql_query, con=con)
I get:
Cannot locate a 64-bit Oracle Client library: "C:\oracle\product\11.2.0\client_1\bin\oci.dll is not the correct architecture". See https://oracle.github.io/odpi/doc/installation.html#windows for help
When I click the link shown in the message, it asks me to run some .exe file. What is this file going to do?
You need to make sure that Python, cx_Oracle and the Oracle client libraries are all the same 64-bit or 32-bit architecture. It sounds like you have a mis-match.
The link given in the error is for HTML documentation; it doesn't run an exe file. The documentation mentions a VS Redistributable is needed - which is an exe file. This is a Microsoft package needed by Oracle Instant Client.
I am trying to trigger hive on spark using hue interface . The job works perfectly when run from commandline but when i try to run from hue it throws exceptions. In hue, I tried mainly two things:
1) when I give all the properties in .hql file using set commands
set spark.home=/usr/lib/spark;
set hive.execution.engine=spark;
set spark.eventLog.enabled=true;
add jar /usr/lib/spark/assembly/lib/spark-assembly-1.5.0-cdh5.5.1-hadoop2.6.0-cdh5.5.1.jar;
set spark.eventLog.dir=hdfs://10.11.50.81:8020/tmp/;
set spark.executor.memory=2899102923;
I get an error
ERROR : Failed to execute spark task, with exception 'org.apache.hadoop.hive.ql.metadata.HiveException(Unsupported execution engine: Spark. Please set hive.execution.engine=mr)'
org.apache.hadoop.hive.ql.metadata.HiveException: Unsupported execution engine: Spark. Please set hive.execution.engine=mr
2) when I give properties in hue properties, it just works with mr engine but not spark execution engine.
Any help would be appreciated
I have solved this issue by using a shell action in oozie.
This shell action invokes a pyspark action bearing my sql file.
Even though the job shows as MR in jobtracker, spark history server recognizes as a spark action and the output is achieved.
shell file:
#!/bin/bash
export PYTHONPATH=`pwd`
spark-submit --master local testabc.py
python file:
from pyspark.sql import HiveContext
from pyspark import SparkContext
sc = SparkContext();
sqlContext = HiveContext(sc)
result = sqlContext.sql("insert into table testing_oozie.table2 select * from testing_oozie.table1 ");
result.show()
I have a robot script which inserts some sql statements from a sql file; some of these statements contain utf8 characters. If I insert this file manually into database using navicat tool, everything's fine. But when I try to execute this file using database library of robot framework, utf8 characters go crazy!
This is my utf8 included sql statement:
INSERT INTO "MY_TABLE" VALUES (2, 'تست1');
This is how I use database library:
Connect To Database Using Custom Params cx_Oracle ${dbConnection}
Execute Sql Script ${sqlFile}
Disconnect From Database
This is what I get in the database:
������������ 1
I have tried to execute the SQL file using cx_Oracle directly and it's still failing! It seems there is a problem in the original library. This is what I've used for importing SQL file:
import cx_Oracle
if __name__ == "__main__":
dsn_tns = cx_Oracle.makedsn(ip, port, sid)
db = cx_Oracle.connect(username, password, dsn_tns)
sql_commands = open(sql_file_addr, 'r').read().split(";")
cr = db.cursor()
for command in sql_commands:
if not command in ["", "\t", "\n", "\r", "\n\r", "\r\n", None]:
print "Executing SQL command:", command
cr.execute(command)
db.commit()
I have found that I can define character-set in the connection string. I've done it for mysql database and it the framework successfully inserted UTF8 characters into database; this is my connection string for MySQL:
database='db_name', user='db_username', password='db_password', host='db_ip', port=3306, charset='utf8'
But I don't know how to define character-set for Oracle connection string. I have tried this:
'db_username','db_password','db_ip:1521/db_sid','utf8'
And I've got this error:
TypeError: an integer is required
As #Yu Zhang suggested, I read discussion in this link and I found out that I should set an environment variable NLS_LANG in order to have a UTF-8 connection to the database. So I've added below line in my test setup:
os.environ["NLS_LANG"] = "AMERICAN_AMERICA.AL32UTF8"
Would any of links below help?
http://docs.oracle.com/cd/B19306_01/server.102/b14225/ch6unicode.htm#i1006779
http://www.theserverside.com/news/thread.tss?thread_id=39575
https://community.oracle.com/thread/502949
There can be several problems in here...
The first problem might be that you don't save the test files using UTF-8 encoding.
Robot framework expects plain text test files to be saved using UTF-8 encoding, yet most text editors will not save by default using UTF-8.
Verify that your editor saves that way - for example, by opening the file using NotePad++ and choosing Encoding -> UTF-8
Another problem might be the connection to the Oracle database. It doesn't seem like you can configure the connection custom properties to explicitly state UTF-8
This means you probably need to state that the database schema itself is UTF-8
I'm trying to dump my data to SQL statements.
the django-admin.py dumpdata provides only json,xml,yaml.
so:
does someone know a good way to do it?!
I tried that:
def sqldumper(model):
result = ""
units = model.objects.all().values()
for unit in units:
statement = "INSERT INTO myapp.model "+str(tuple(unit.keys())).replace("'", "")+" VALUES " + str(tuple(unit.values()))+"\r\n"
result+=statement
return result
so I'm going over the model values myself, and make the INSERT statement myself.
then I thought of using "django-admin.py sql" to get the "CREATE" statement.. but then I don't know how to use this line from inside my code (and not through the command-line).
I tried os.popen and os.system, but it doesn't really work..
any tips about that?
I'll put it clearly:
how do you use the "manage.py sql " from inside your code?
I add something like this to my view:
import os, sys
import imp
from django.core.management import execute_manager
sys_argv_backup = sys.argv
imp.find_module("settings")
import settings
sys.argv = ['','sql','myapp']
execute_manager(settings)
sys.argv = sys_argv_backup
the thing is - it works.. but it writes the statements to the stdout...
it's something, but not perfect. I'll try using django.core.management.sql.sql_create directly, we'll see how it goes..
thanks
I suggest to use SQL-specific dump program (e.g. mysqldump for MySQL).
For sqlite embedded in Python, you can look this example not involving Django:
# Convert file existing_db.db to SQL dump file dump.sql
import sqlite3, os
con = sqlite3.connect('existing_db.db')
with open('dump.sql', 'w') as f:
for line in con.iterdump():
f.write('%s\n' % line)
How can I execute whole sql file into database using SQLAlchemy? There can be many different sql queries in the file including begin and commit/rollback.
sqlalchemy.text or sqlalchemy.sql.text
The text construct provides a straightforward method to directly execute .sql files.
from sqlalchemy import create_engine
from sqlalchemy import text
# or from sqlalchemy.sql import text
engine = create_engine('mysql://{USR}:{PWD}#localhost:3306/db', echo=True)
with engine.connect() as con:
with open("src/models/query.sql") as file:
query = text(file.read())
con.execute(query)
SQLAlchemy: Using Textual SQL
text()
I was able to run .sql schema files using pure SQLAlchemy and some string manipulations. It surely isn't an elegant approach, but it works.
# Open the .sql file
sql_file = open('file.sql','r')
# Create an empty command string
sql_command = ''
# Iterate over all lines in the sql file
for line in sql_file:
# Ignore commented lines
if not line.startswith('--') and line.strip('\n'):
# Append line to the command string
sql_command += line.strip('\n')
# If the command string ends with ';', it is a full statement
if sql_command.endswith(';'):
# Try to execute statement and commit it
try:
session.execute(text(sql_command))
session.commit()
# Assert in case of error
except:
print('Ops')
# Finally, clear command string
finally:
sql_command = ''
It iterates over all lines in a .sql file ignoring commented lines.
Then it concatenates lines that form a full statement and tries to execute the statement. You just need a file handler and a session object.
You can do it with SQLalchemy and psycopg2.
file = open(path)
engine = sqlalchemy.create_engine(db_url)
escaped_sql = sqlalchemy.text(file.read())
engine.execute(escaped_sql)
Unfortunately I'm not aware of a good general answer for this. Some dbapi's (psycopg2 for instance) support executing many statements at a time. If the files aren't huge you can just load them into a string and execute them on a connection. For others, I would try to use a command-line client for that db and pipe the data into that using the subprocess module.
If those approaches aren't acceptable, then you'll have to go ahead and implement a small SQL parser that can split the file apart into separate statements. This is really tricky to get 100% correct, as you'll have to factor in database dialect specific literal escaping rules, the charset used, any database configuration options that affect literal parsing (e.g. PostgreSQL standard_conforming_strings).
If you only need to get this 99.9% correct, then some regexp magic should get you most of the way there.
If you are using sqlite3 it has a useful extension to dbapi called conn.executescript(str), I've hooked this up via something like this and it seemed to work: (Not all context is shown but it should be enough to get the drift)
def init_from_script(script):
Base.metadata.drop_all(db_engine)
Base.metadata.create_all(db_engine)
# HACK ALERT: we can do this using sqlite3 low level api, then reopen session.
f = open(script)
script_str = f.read().strip()
global db_session
db_session.close()
import sqlite3
conn = sqlite3.connect(db_file_name)
conn.executescript(script_str)
conn.commit()
db_session = Session()
Is this pure evil I wonder? I looked in vain for a 'pure' sqlalchemy equivalent, perhaps that could be added to the library, something like db_session.execute_script(file_name) ? I'm hoping that db_session will work just fine after all that (ie no need to restart engine) but not sure yet... further research needed (ie do we need to get a new engine or just a session after going behind sqlalchemy's back?)
FYI sqlite3 includes a related routine: sqlite3.complete_statement(sql) if you roll your own parser...
You can access the raw DBAPI connection through this
raw_connection = mySqlAlchemyEngine.raw_connection()
raw_cursor = raw_connection() #get a hold of the proxied DBAPI connection instance
but then it will depend on which dialect/driver you are using which can be referred to through this list.
For pyscog2, you can just do
raw_cursor.execute(open("my_script.sql").read())
but pysqlite you would need to do
raw_cursor.executescript(open("my_script").read())
and in line with that you would need to check the documentation of whichever DBAPI driver you are using to see if multiple statements are allowed in one execute or if you would need to use a helper like executescript which is unique to pysqlite.
Here's how to run the script splitting the statements, and running each statement directly with a "connectionless" execution with the SQLAlchemy Engine. This assumes that each statement ends with a ; and that there's no more than one statement per line.
engine = create_engine(url)
with open('script.sql') as file:
statements = re.split(r';\s*$', file.read(), flags=re.MULTILINE)
for statement in statements:
if statement:
engine.execute(text(statement))
In the current answers, I did not found a solution which works when a combination of these features in the .SQL file is present:
Comments with "--"
Multi-line statements with additional comments after "--"
Function definitions which have multiple SQL-queries ending with ";" butmust be executed as a whole statement
A found a rather simple solution:
# check for /* */
with open(file, 'r') as f:
assert '/*' not in f.read(), 'comments with /* */ not supported in SQL file python interface'
# we check out the SQL file line-by-line into a list of strings (without \n, ...)
with open(file, 'r') as f:
queries = [line.strip() for line in f.readlines()]
# from each line, remove all text which is behind a '--'
def cut_comment(query: str) -> str:
idx = query.find('--')
if idx >= 0:
query = query[:idx]
return query
# join all in a single line code with blank spaces
queries = [cut_comment(q) for q in queries]
sql_command = ' '.join(queries)
# execute in connection (e.g. sqlalchemy)
conn.execute(sql_command)
Code bellow works for me in alembic migrations
from alembic import op
import sqlalchemy as sa
from ekrec.common import get_project_root
def upgrade():
path = f'{get_project_root()}/migrations/versions/fdb8492f75b2_.sql'
op.execute(open(path).read())
I had success with David's answer here, with two slight modifications:
Use get_bind() as I was working with a Session rather than an Engine
Call cursor() on the raw connection
raw_connection = myDbSession.get_bind().raw_connection()
raw_cursor = raw_connection.cursor()
raw_cursor.execute(open("my_script.sql").read())