I would like to read row by row in python from Oracle Select query. I have to build a logic based on the data I am getting from Oracle for specific columns.
I am using cx_Oracle.connect
dsnStr = cx_Oracle.makedsn("xxxx.net", "6000", "XVTRR") # Dev envrionment
con = cx_Oracle.connect(user="SCOTT", password="TIGER", dsn=dsnStr)
print con.version
cursor = con.cursor()
cursor.execute("select * from user_tables where rownum<=1 order by TABLE_NAME")
rows = cursor.fetchall()
col_names=[]
for i in range(0, len(cursor.description)):
col_names.append(cursor.description[i][0])
pp = pprint.PrettyPrinter(width=1024)
pp.pprint(col_names)
pp.pprint(rows)
cursor.close()
con.close()
Please help me.
Related
import mysql.connector
connection = mysql.connector.connect(user="REMOVED",
password="REMOVED",
host="REMOVED",
database="REMOVED")
cur = connection.cursor()
# Latitude - remove letter A
cur.execute("UPDATE tau._inm_exportados_test_csv SET latitud = REPLACE (latitud, 'a=','');")
print("Latitude change remove letter A - executed!")
# Longitude - remove letter A
cur.execute("UPDATE tau._inm_exportados_test_csv SET longitud = REPLACE (longitud, 'a=','');")
print("Longitude change remove letter A - executed!")
# Latitude - MODIFY COLUMN
cur.execute("ALTER TABLE tau._inm_exportados_test_csv MODIFY COLUMN latitud DECIMAL(10,6);")
print("Latitude - MODIFY COLUMN - executed!")
# Longitude - MODIFY COLUMN
cur.execute("ALTER TABLE tau._inm_exportados_test_csv MODIFY COLUMN longitud DECIMAL(10,6);")
print("Longitude - MODIFY COLUMN - executed!")
# Post Code data type change
cur.execute("ALTER TABLE tau._inm_exportados_test_csv MODIFY COLUMN codigo_postal varchar(255);)")
print("Post Code data type change to varchar(255) - executed!")
connection.commit()
cur.close()
connection.close()
I'm trying to make this simple list of statements work without success. What makes it more confusing is that the first four statements work whereas the final one doesn't work even when I comment out the rest! The final statement gets the following reponse:
mysql.connector.errors.InterfaceError: Use multi=True when executing multiple statements
The datatype for codigo_postal is int(11) unlike latitud and longitud which are varchar.
I have tried creating new connections, new cursors, new connections AND cursors. I have tried adding multi="True" and combining statements into one operation. I have tried adding multi="True" to each cur.execute() as both the second and third parameter. I have run the statement in Workbench to ensure the statement is valid and it works.
No success with it here though...
You can use commit after you executed DML (Data Manipulation Language) commands. Also using multi=True can be more convenient to complete this job, but you need to run the generator which created by execute. doc.
Ordinary method:
cur = connection.cursor()
def alter(state,msg):
try:
cur.execute(state)
connection.commit()
except Exception as e:
connection.rollback()
raise e
print(msg)
alter("ALTER TABLE address MODIFY COLUMN id int(15);","done")
alter("ALTER TABLE address MODIFY COLUMN email varchar(35);","done")
alter("ALTER TABLE address MODIFY COLUMN person_id int(35);","done")
With multi=True:
cur = connection.cursor()
def alter(state,msg):
result = cur.execute(state,multi=True)
result.send(None)
print(msg,result)
try:
alter("ALTER TABLE address MODIFY COLUMN id int(45)","done")
alter("ALTER TABLE address MODIFY COLUMN email varchar(25)","done")
alter("ALTER TABLE address MODIFY COLUMN person_id int(25);","done")
connection.commit()
except Exception as e:
connection.rollback()
raise e
I had the same problem.
I wanted my code to be clean and I wanted to have all my commands in a list and just run them in a sequence.
I found this link and this link and finally was able to write this code:
import mysql.connector as sql
from mysql.connector import Error
commands = [
'''
USE sakila;
SELECT * FROM actor;
''',
'''
USE sakila;
SELECT * FROM actor WHERE actor_id < 10;
'''
]
connection_config_dict = {
'user': 'username',
'password': 'password',
'host': '127.0.0.1',
}
try:
connection = sql.connect(**connection_config_dict)
if connection.is_connected():
db_Info = connection.get_server_info()
print("Connected to MySQL Server version ", db_Info, '\n')
cursor = connection.cursor()
for command in commands:
for result in cursor.execute(command, multi=True):
if result.with_rows:
print("Rows produced by statement '{}':".format(
result.statement))
print(result.fetchall())
else:
print("Number of rows affected by statement '{}': {}".format(
result.statement, result.rowcount), '\n')
record = cursor.fetchall()
except Error as e:
print("Error while connecting to MySQL", e, '\n')
finally:
if connection.is_connected():
cursor.close()
connection.close()
print("MySQL connection is closed", '\n')
I am very new to sql and intermediate at python. Using sqlite3, how can I get a print() list of of primary and foreign keys (per table) in my database?
Using Python2.7, SQLite3, PyCharm.
sqlite3.version = 2.6.0
sqlite3.sqlite_version = 3.8.11
Also note: when I set up the database, I enabled FKs as such:
conn = sqlite3.connect(db_file)
conn.execute('pragma foreign_keys=ON')
I tried the following:
conn=sqlite3.connect(db_path)
print(conn.execute("PRAGMA table_info"))
print(conn.execute("PRAGMA foreign_key_list"))
Which returned:
<sqlite3.Cursor object at 0x0000000002FCBDC0>
<sqlite3.Cursor object at 0x0000000002FCBDC0>
I also tried the following, which prints nothing (but I think this may be because it's a dummy database with tables and fields but no records):
conn=sqlite3.connect(db_path)
rows = conn.execute('PRAGMA table_info')
for r in rows:
print r
rows2 = conn.execute('PRAGMA foreign_key_list')
for r2 in rows2:
print r2
Unknown or malformed PRAGMA statements are ignored.
The problem with your PRAGMAs is that the table name is missing. You have to get a list of all tables, and then execute those PRAGMAs for each one:
rows = db.execute("SELECT name FROM sqlite_master WHERE type = 'table'")
tables = [row[0] for row in rows]
def sql_identifier(s):
return '"' + s.replace('"', '""') + '"'
for table in tables:
print("table: " + table)
rows = db.execute("PRAGMA table_info({})".format(sql_identifier(table)))
print(rows.fetchall())
rows = db.execute("PRAGMA foreign_key_list({})".format(sql_identifier(table)))
print(rows.fetchall())
SELECT
name
FROM
sqlite_master
WHERE
type ='table' AND
name NOT LIKE 'sqlite_%';
this sql will show all table in database, for eache table run sql PRAGMA table_info(your_table_name);, you can get the primary key of the table.
Those pictures show what sql result like in my database:
first sql result
second sql result
I am using
Python 2.7
cx_Oracle 6.0.2
I am doing something like this in my code
import cx_Oracle
connection_string = "%s:%s/%s" % ("192.168.8.168", "1521", "xe")
connection = cx_Oracle.connect("system", "oracle", connection_string)
cur = connection.cursor()
print "Connection Version: {}".format(connection.version)
query = "select *from product_information"
cur.execute(query)
result = cur.fetchone()
print result
I got the output like this
Connection Version: 11.2.0.2.0
(1, u'????????????', 'test')
I am using following query to create table in oracle database
CREATE TABLE product_information
( product_id NUMBER(6)
, product_name NVARCHAR2(100)
, product_description VARCHAR2(1000));
I used the following query to insert data
insert into product_information values(2, 'दुःख', 'teting');
Edit 1
Query: SELECT * from NLS_DATABASE_PARAMETERS WHERE parameter IN ( 'NLS_LANGUAGE', 'NLS_TERRITORY', 'NLS_CHARACTERSET');
Result
NLS_LANGUAGE: AMERICAN, NLS_TERRITORY: AMERICA, NLS_CHARACTERSET:
AL32UTF8
I solved the problem.
First I added NLS_LANG=.AL32UTF8 as the environment variable in the system where Oracle is installed
Second I passed the encoding and nencoding parameter in connect function of cx_Oracle like below.
cx_Oracle.connect(username, password, connection_string,
encoding="UTF-8", nencoding="UTF-8")
This issue is also discussed here at https://github.com/oracle/python-cx_Oracle/issues/157
I'm a newbie to python and i am trying to insert some data in to a mysql table .Seems the query executed with out any issues, however i don't see any record added on to the table.
Any help would be greatly appreciated.
Cheers,
Aditya
connection = mysql.connector.connect(user='sandboxbeta2503', password='XXX',
host='myreleasebox.com',
database='iaas')
print ("Updating the history in bulk_notification_history")
cursor = connection.cursor()
timestamp = time.strftime("%Y-%m-%d %X")
notification_type = "Notify Inactive users"
usercount= 45
query = ("INSERT INTO iaas.bulk_notification_history"
"(nty_date,notification_type,user_count)"
"VALUES (%s,%s,%s)")
data = (time.strftime('%Y-%m-%d %H:%M:%S'),notification_type, usercount)
linker1 = cursor.execute(query,data)
print (linker1)
cursor.close()
connection.close()
I found put that I open the database at every request.Is there a way to simplify and improve this code to increase the sqlite speed?
name3 = ' '.join(name2)
import sqlite3
id = 0
location = ""
conn = sqlite3.connect("keywords.db")
c = conn.cursor()
c.execute('select * from kmedicals')
records = c.fetchall()
for record in records:
id = record[0]
location = record[15]
if id == name3:
print name3.capitalize(),':' '\n',location
break
sys.exit()
Do not use import in the middle of your program.
Open the database once at the start of your program.
Select only the records you actually need.
Select only the columns you actually need.
Do not use fetchall; read only the records you actually need.
Do not fetch into a temporary variable if you can use the cursor directly.
import sqlite3
# at startup
conn = sqlite3.connect("keywords.db")
def search_location(name2):
name3 = ' '.join(name2)
c = conn.cursor()
c.execute('SELECT location FROM kmedicals WHERE id = ?', (name3,))
for (location,) in c:
print name3.capitalize(),':' '\n',location
break
else:
pass # not found