This is the error:
mysql.connector.errors.ProgrammingError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'database' at line 1
Here is the code that I use to create the database:
import mysql.connector
mydb = mysql.connector.connect(
host="localhost",
user="root",
passwd = "password12",
)
my_cursor = mydb.cursor()
my_cursor.execute("CREATE DATABASE database")
my_cursor.execute("SHOW DATABASES")
for db in my_cursor:
print(db)
I tried using a different name for the database, but I still got the same error.
You have an extraneous comma after your password parameter. Change your mydb connection string to the following:
import mysql.connector
mydb = mysql.connector.connect(
host = 'localhost',
user = 'root',
password = 'password12'
)
my_cursor = mydb.cursor()
my_cursor.execute("CREATE DATABASE database")
my_cursor.execute("SHOW DATABASES")
for db in my_cursor:
print(db)
You should use the word password over passwd. Even though they're synonymous, according to the MySQL documentation here: Connector/Python Connection Arguments
An asterisk (*) following an argument indicates a synonymous argument
name, available only for compatibility with other Python MySQL
drivers. Oracle recommends not to use these alternative names.
Argument Name
Default
Description
user (username*)
The user name used to authenticate with the MySQL server.
password (passwd*)
The password to authenticate the user with the MySQL server.
password1, password2, and password3
For Multi-Factor Authentication (MFA); password1 is an alias for password. Added in 8.0.28.
database (db*)
The database name to use when connecting with the MySQL server.
host
127.0.0.1
The host name or IP address of the MySQL server.
Also, as mentioned in the comments above, you should not use the word database as your actual database name. I understand you may be doing it as an example, but its worth noting that it is a Reserved Keyword.
import pyhdb
connect = pyhdb.connect(
host="example.com",
port=30015,
user="user",
password="secret"
)
From the official explanation
Pyhdb only gives four parameters. Without the parameter database name, I can't understand how the system knows which database you want to connect to in this case?
And when i connect in this way, Program error："pyhdb.exceptions.DatabaseError: authentication failed",
it looks like my password is wrong, so i let friends use JAVA(jdbc) to connect with four parameters,
it failed too, but if he add database name, it worked! so my parameters is right , and question is how to specify database name in pyhdb?
Or there are other ways to connect to Hana, Thankyou!
Looking at the __init__.py file of the pyhdb package shows that DATABASENAME is not supported when creating a connection:
[...]
def connect(host, port, user, password, autocommit=False):
conn = Connection(host, port, user, password, autocommit)
conn.connect()
return conn
[...]
The good news here is that pyhdb is not what you should be using to connect to HANA anyhow as it is the old and unsupported client library.
Use hdbcli instead as described in the documentation.
With hdbcli it's no problem at all to use the DATABASENAME:
from hdbcli import dbapi
connection =dbapi.connect(address="hxehost", port=39013, databasename="HXE", user="xxxxx", password="xxxxx")
cursor = connection.cursor()
cursor.execute("SELECT 'Hello, Python world' FROM DUMMY")
print(cursor.fetchone())
connection.close()
Using the psycopg2 module to connect to the PostgreSQL database using python. Able to execute all queries using the below connection method. Now I want to specify a different schema than public to execute my SQL statements. Is there any way to specify the schema name in the connection method?
conn = psycopg2.connect(host="localhost",
port="5432",
user="postgres",
password="password",
database="database",
)
I tried to specify schema directly inside the method.
schema="schema2"
But I am getting the following programming error.
ProgrammingError: invalid dsn: invalid connection option "schema"
When we were working on ThreadConnectionPool which is in psycopg2 and creating connection pool, this is how we did it.
from psycopg2.pool import ThreadedConnectionPool
db_conn = ThreadedConnectionPool(
minconn=1, maxconn=5,
user="postgres", password="password", database="dbname", host="localhost", port=5432,
options="-c search_path=dbo,public"
)
You see that options key there in params. That's how we did it.
When you execute a query using the cursor from that connection, it will search across those schemas mentioned in options i.e., dbo,public in sequence from left to right.
You may try something like this:
psycopg2.connect(host="localhost",
port="5432",
user="postgres",
password="password",
database="database",
options="-c search_path=dbo,public")
Hope this might help you.
If you are using the string form you need to URL escape the options argument:
postgresql://localhost/airflow?options=-csearch_path%3Ddbo,public
(%3D = URL encoding of =)
This helps if you are using SQLAlchemy for example.
sqlplus sys/Oracle_1#pdborcl as sysdba;
i'm using this command to connect to Oracle 12c from Command Prompt.
How can i connect to the db using cx_Oracle. I'm new to Oracle DB.
I think this is the equivalent of the sqlplus command line that you posted:
import cx_Oracle
connect_string = "sys/Oracle_1#pdborcl"
con = cx_Oracle.connect(connect_string,mode=cx_Oracle.SYSDBA)
I tried it with a non-container database and not with a pdb so I can't verify that it would work with a pdb. You may not want to connect as sys as sysdba unless you know that you need that level of security.
Bobby
You can find the documentation here cx_Oracle docs
To query the database, use the below algorithm
import cx_Oracle
dsn = cx_Oracle.makedsn(host, port, sid)
connection = cx_Oracle.connect(dsn,mode = cx_Oracle.SYSDBA)
query = "SELECT * FROM MYTABLE"
cursor = connection.cursor()
cursor.execute(query)
resultSet=cursor.fetchall()
connection.close()
The above code works to fetch data from MYTABLE connecting to the above dsn.
Better to go through cx_Oracle docs.
How can I access Oracle from Python? I have downloaded a cx_Oracle msi installer, but Python can't import the library.
I get the following error:
import cx_Oracle
Traceback (most recent call last):
File "<pyshell#1>", line 1, in <module>
import cx_Oracle
ImportError: DLL load failed: The specified module could not be found.
I will be grateful for any help.
Here's what worked for me. My Python and Oracle versions are slightly different from yours, but the same approach should apply. Just make sure the cx_Oracle binary installer version matches your Oracle client and Python versions.
My versions:
Python 2.7
Oracle Instant Client 11G R2
cx_Oracle 5.0.4 (Unicode, Python 2.7, Oracle 11G)
Windows XP SP3
Steps:
Download the Oracle Instant Client package. I used instantclient-basic-win32-11.2.0.1.0.zip. Unzip it to C:\your\path\to\instantclient_11_2
Download and run the cx_Oracle binary installer. I used cx_Oracle-5.0.4-11g-unicode.win32-py2.7.msi. I installed it for all users and pointed it to the Python 2.7 location it found in the registry.
Set the ORACLE_HOME and PATH environment variables via a batch script or whatever mechanism makes sense in your app context, so that they point to the Oracle Instant Client directory. See oracle_python.bat source below. I'm sure there must be a more elegant solution for this, but I wanted to limit my system-wide changes as much as possible. Make sure you put the targeted Oracle Instant Client directory at the beginning of the PATH (or at least ahead of any other Oracle client directories). Right now, I'm only doing command-line stuff so I just run oracle_python.bat in the shell before running any programs that require cx_Oracle.
Run regedit and check to see if there's an NLS_LANG key set at \HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE. If so, rename the key (I changed it to NLS_LANG_OLD) or unset it. This key should only be used as the default NLS_LANG value for Oracle 7 client, so it's safe to remove it unless you happen to be using Oracle 7 client somewhere else. As always, be sure to backup your registry before making changes.
Now, you should be able to import cx_Oracle in your Python program. See the oracle_test.py source below. Note that I had to set the connection and SQL strings to Unicode for my version of cx_Oracle.
Source: oracle_python.bat
#echo off
set ORACLE_HOME=C:\your\path\to\instantclient_11_2
set PATH=%ORACLE_HOME%;%PATH%
Source: oracle_test.py
import cx_Oracle
conn_str = u'user/password#host:port/service'
conn = cx_Oracle.connect(conn_str)
c = conn.cursor()
c.execute(u'select your_col_1, your_col_2 from your_table')
for row in c:
print row[0], "-", row[1]
conn.close()
Possible Issues:
"ORA-12705: Cannot access NLS data files or invalid environment specified" - I ran into this before I made the NLS_LANG registry change.
"TypeError: argument 1 must be unicode, not str" - if you need to set the connection string to Unicode.
"TypeError: expecting None or a string" - if you need to set the SQL string to Unicode.
"ImportError: DLL load failed: The specified procedure could not be found." - may indicate that cx_Oracle can't find the appropriate Oracle client DLL.
You can use any of the following way based on Service Name or SID whatever you have.
With SID:
import cx_Oracle
dsn_tns = cx_Oracle.makedsn('server', 'port', 'sid')
conn = cx_Oracle.connect(user='username', password='password', dsn=dsn_tns)
c = conn.cursor()
c.execute('select count(*) from TABLE_NAME')
for row in c:
print(row)
conn.close()
OR
With Service Name:
import cx_Oracle
dsn_tns = cx_Oracle.makedsn('server', 'port', service_name='service_name')
conn = cx_Oracle.connect(user='username', password='password', dsn=dsn_tns)
c = conn.cursor()
c.execute('select count(*) from TABLE_NAME')
for row in c:
print(row)
conn.close()
Here is how my code looks like. It also shows an example of how to use query parameters using a dictionary. It works on using Python 3.6:
import cx_Oracle
CONN_INFO = {
'host': 'xxx.xx.xxx.x',
'port': 12345,
'user': 'SOME_SCHEMA',
'psw': 'SECRETE',
'service': 'service.server.com'
}
CONN_STR = '{user}/{psw}#{host}:{port}/{service}'.format(**CONN_INFO)
QUERY = '''
SELECT
*
FROM
USER
WHERE
NAME = :name
'''
class DB:
def __init__(self):
self.conn = cx_Oracle.connect(CONN_STR)
def query(self, query, params=None):
cursor = self.conn.cursor()
result = cursor.execute(query, params).fetchall()
cursor.close()
return result
db = DB()
result = db.query(QUERY, {'name': 'happy'})
import cx_Oracle
dsn_tns = cx_Oracle.makedsn('host', 'port', service_name='give service name')
conn = cx_Oracle.connect(user='username', password='password', dsn=dsn_tns)
c = conn.cursor()
c.execute('select count(*) from schema.table_name')
for row in c:
print row
conn.close()
Note :
In (dsn_tns) if needed, place an 'r' before any parameter in order to address any special character such as '\'.
In (conn) if needed, place an 'r' before any parameter in order to address any special character such as '\'. For example, if your user name contains '\', you'll need to place 'r' before the user name: user=r'User Name' or password=r'password'
use triple quotes if you want to spread your query across multiple lines.
Note if you are using pandas you can access it in following way:
import pandas as pd
import cx_Oracle
conn= cx_Oracle.connect('username/pwd#host:port/service_name')
try:
query = '''
SELECT * from dual
'''
df = pd.read_sql(con = conn, sql = query)
finally:
conn.close()
df.head()
In addition to the Oracle instant client, you may also need to install the Oracle ODAC components and put the path to them into your system path. cx_Oracle seems to need access to the oci.dll file that is installed with them.
Also check that you get the correct version (32bit or 64bit) of them that matches your: python, cx_Oracle, and instant client versions.
In addition to cx_Oracle, you need to have the Oracle client library installed and the paths set correctly in order for cx_Oracle to find it - try opening the cx_Oracle DLL in "Dependency Walker" (http://www.dependencywalker.com/) to see what the missing DLL is.
Ensure these two and it should work:-
Python, Oracle instantclient and cx_Oracle are 32 bit.
Set the environment variables.
Fixes this issue on windows like a charm.
If you are using virtualenv, it is not as trivial to get the driver using the installer. What you can do then: install it as described by Devon. Then copy over cx_Oracle.pyd and the cx_Oracle-XXX.egg-info folder from Python\Lib\site-packages
into the Lib\site-packages from your virtual env. Of course, also here, architecture and version are important.
import cx_Oracle
from sshtunnel import SSHTunnelForwarder
# remote server variables
remote_ip_address = "<PUBLIC_IP_ADDRESS_OF_DB_SERVER>"
remote_os_username = "<OS_USERNAME>"
ssh_private_key = "<PATH_TO_PRIVATE_KEY>"
# Oracle database variables
database_username = "<DATABASE_USER>"
database_password = "<DATABASE_USER_PASSWORD>"
database_server_sid = "<ORACLE_SID>"
def server_connection():
server = SSHTunnelForwarder(
remote_ip_address,
ssh_username=remote_os_username,
ssh_password=ssh_private_key,
remote_bind_address=('localhost', 1521) # default Oracle DB port
)
return server
def database_connection():
data_source_name = cx_Oracle.makedsn("localhost",
server.local_bind_port,
service_name=database_server_sid)
connection = cx_Oracle.connect(database_username,
database_password,
data_source_name,
mode=cx_Oracle.SYSDBA) # If logging in with SYSDBA privs,
# leave out if not.
return connection
def database_execute():
connection = database_connection()
cursor = connection.cursor()
for row in cursor.execute("SELECT * FROM HELLO_WORLD_TABLE"):
print(row)
if __name__ == '__main__':
server = server_connection()
server.start() # start remote server connection
connection = database_connection() # create Oracle database connection
database_execute() # execute query
connection.close() # close Oracle database connection
server.stop() # close remote server connection
If you're accessing the Oracle database via a bastion tunnel, you just need to modify this piece of code:
def server_connection():
server = SSHTunnelForwarder(
remote_ip_address, # public IP of bastion server
ssh_username=remote_os_username,
ssh_password=ssh_private_key,
remote_bind_address=('localhost', 1521),
local_bind_address=('0.0.0.0', 3333) # Suppose local bind is '3333'
)
return server