I'm trying to read the Table names from a database into a list using Pandas.read_sql.
I have tried different SQL queries found online:
cnxn = pyodbc.connect('DRIVER={Microsoft Access Driver (*.mdb)};DBQ=' + str(self.file_selected)+';Uid=Admin;Pwd=; ')
# sql = "SELECT * FROM SYS.TABLES" # tried this - also an error
sql = "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_SCHEMA='database_name.MDB'"
self.TableNames = pd.io.sql.read_sql(sql, cnxn)
cnxn.close()
but I get an error that it can not find the file database_name.INFORMATION_SCHEMA.TABLES
what should I use for the sql query?
In MS Access, you can retrieve metadata on a database using its system table, MSysObjects. Below is a DML call to retrieve all table names:
SELECT MSysObjects.Name
FROM MsysObjects
WHERE ((MSysObjects.Type)=1)
ORDER BY MSysObjects.Name;
However, by default this will not work with external ODBC calls such as you do in Python as permission is not allowed. To resolve, consider two routes:
Grant Permission (for Admin user)
Inside the MSAccess.exe GUI, open database and run VBA subroutine (in standalone module) which only needs to be run once:
Public Sub GrantMSysPermission()
Dim strSQL As String
strSQL = "GRANT SELECT ON MSysObjects TO Admin;"
CurrentProject.Connection.Execute strSQL
End Sub
Once done run above query in pandas read_sql call.
Saved Table
Inside MS Access.exe GUI program, run below make-table query:
SELECT MSysObjects.Name
INTO DBTables
FROM MsysObjects
WHERE ((MSysObjects.Type)=1)
ORDER BY MSysObjects.Name;
Then in Python pandas, refer to new table:
cnxn = pyodbc.connect('DRIVER={{Microsoft Access Driver (*.mdb)}};DBQ=' + \
'{};Uid=Admin;Pwd=;'.format(str(self.file_selected)))
sql = "SELECT * DBTables"
self.TableNames = pd.io.sql.read_sql(sql, cnxn)
cnxn.close()
Related
I want to access my database by using python script .
I can able to access all table by using
SELECT * FROM poorvika1.payment;
But i want to access the query by using VIEW Statement
SELECT * FROM poorvika1.pymentview;
This is my python script
import pyodbc
for py in pyodbc.drivers():
print(py)
connection =pyodbc.connect(driver='SQL Server',server='localhost',database='test',uid='test',password='root')
cursor = connection.cursor()
for row in cursor.tables():
print(row.table_name)
This Query is not working
cursor.execute('SELECT * FROM poorvika1.pymentview')
I want to access view query in pyodbc package
did you tried
cursor.execute('SELECT * FROM poorvika1..pymentview')
for row in cursor:
print(row)
Creating a list in python and inserting into oracle table , but no records found in oracle table.
Created a list in python.
Created a Oracle table using Python code.
Using executeMany inserted the list.
Run the count(*) query in python and obtained the number of rows and printed in python.
Output : Table has been created in Oracle using python code succesfully , but cannot find the records inserted using python
import cx_Oracle
con = cx_Oracle.connect('username/password#127.0.0.1/orcl')
cursor = con.cursor()
create_table = """CREATE TABLE python_modules ( module_name VARCHAR2(1000) NOT NULL, file_path VARCHAR2(1000) NOT NULL )"""
cursor.execute(create_table)
M = []
M.append(('Module1', 'c:/1'))
M.append(('Module2', 'c:/2'))
M.append(('Module3', 'c:3'))
cursor.prepare("INSERT INTO python_modules(module_name, file_path) VALUES (:1, :2)")
cursor.executemany(None,M)
con.commit
cursor.execute("SELECT COUNT(*) FROM python_modules")
print(cursor.fetchone() [0])
Executing below query "select * from python_modules " should have the 3 records in Oracle SQL Developer tool
Change your commit to con.commit().
I'm currently trying to query a deltadna database. Their Direct SQL Access guide states that any PostgreSQL ODBC compliant tools should be able to connect without issue. Using the guide, I set up an ODBC data source in windows
I have tried adding Set nocount on, changed various formats for the connection string, changed the table name to be (account).(system).(tablename), all to no avail. The simple query works in Excel and I have cross referenced with how Excel formats everything as well, so it is all the more strange that I get the no query problem.
import pyodbc
conn_str = 'DSN=name'
query1 = 'select eventName from table_name limit 5'
conn = pyodbc.connect(conn_str)
conn.setdecoding(pyodbc.SQL_CHAR,encoding='utf-8')
query1_cursor = conn.cursor().execute(query1)
row = query1_cursor.fetchone()
print(row)
Result is ProgrammingError: No results. Previous SQL was not a query.
Try it like this:
import pyodbc
conn_str = 'DSN=name'
query1 = 'select eventName from table_name limit 5'
conn = pyodbc.connect(conn_str)
conn.setdecoding(pyodbc.SQL_CHAR,encoding='utf-8')
query1_cursor = conn.cursor()
query1_cursor.execute(query1)
row = query1_cursor.fetchone()
print(row)
You can't do the cursor declaration and execution in the same row. Since then your query1_cursor variable will point to a cursor object which hasn't executed any query.
I am saving MS Access tables as CSV files using Python. There is a table in the MS Access database that is named 'Perm_Site Info'. There is a space in the naming in MS Access. When I run the below snippet, the code blows up. I have tried having single and as well as double quotes in the cursor.execute but no fruition. I request your kind assistance in order to understand how to fix this.
import pyodbc
import csv
conn_string = ("DRIVER={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=C:\\Access\\permissions.accdb")
conn = pyodbc.connect(conn_string)
cursor = conn.cursor()
cursor.execute("select * from Perm_Site Info;")
with open('C:\\Desktop\\Python Files\\Perms_Site_Info.csv','wb') as csvfile:
writer = csv.writer(csvfile)
writer.writerow([i[0] for i in cursor.description])
writer.writerows(cursor)
cursor.close()
conn.close()
print 'All done for now'
The error:
cursor.execute("select * from Perm_Site Info;")
ProgrammingError: ('42S02', "[42S02] [Microsoft][ODBC Microsoft Access Driver] The Microsoft Access database engine cannot find the input table or query 'Perm_Site'. Make sure it exists and that its name is spelled correctly. (-1305) (SQLExecDirectW)")
Try using brackets around the entire table name. It's barking because it doesn't know what to do with the space.
cursor.execute("select * from [Perm_Site Info];")
I am trying to load a big list of sql queries into a table in Vertica using PYODBC. Here's my code:
tablename = DVXTEMP.my_table_name
sql = my_sql_query.strip().strip(';')
samplesize = 1000
createstring = 'CREATE TABLE %s AS %s \n limit %s;' %(tablename, sql, samplesize)
cursor.execute(createstring)
when I print createstring and run it in Toad, it works fine. when I try to execute it in pyodbc, it gives me the following error:
'Syntax error at or near "DVXTEMP" at character 1\n (4856) (SQLExecDirectW)'
We are using Vertica Analytic Database v7.1.2-6
Any ideas what might be causing this?
Thanks
1) did you import pyodbc?
2) did you define "cursor" from "pyodbc.connect"?
import pyodbc
DB = '[string for dbfile]'
DRV = '[string of which driver you are going to use]'
con = pyodbc.connect('DRIVER={};DBQ={}'.format(DRV,DB))
cursor = con.cursor()
##build SQL code and execute as you have done
Try SQL commands after you can connect without an error.
3) I use pyodbc for mdb files (MS Access) and some of my queries will not run unless I put single quotes outside double quotes on table/field names.
mytbl_1 = "mytbl"
SQL = 'SELECT * FROM ' + mytbl_1
print SQL
print result -> SELECT * FROM mytbl
(this fails)
mytbl_2 = '"mytbl"' #single quotes outside of double quote
SQL = 'SELECT * FROM ' + mytbl_2
print SQL
print result -> SELECT * FROM "mytbl"
(this string gets passed w/o error works for me with MDB files)