psycopg, double and single quotes insert - python

I ran into problems, while trying to insert to database:
ur_psql.execute("""insert into smth(data, filedate, filedby)"""
""" values('%s', NOW(), %s)""" % (data, userid))
where data=""" "5.09,448,1418112000"; d="scan'208" """(a string containing double and single quotes)
Any ideas how to insert such string to db ?
Thanks

You can read about it at: http://initd.org/psycopg/docs/usage.html#the-problem-with-the-query-parameters
Simply do not use quotes in SQL and instead of % string Python operator use 2nd parameter of execute() which is data you want to pass to SQL query:
sql = "insert into smth (data, filedate, filedby) values (%s, NOW(), %s)"
ur_psql.execute(sql, (data, userid))

Related

How to INSERT query a list of elements in python

I have tried to query all elements from a list into an insertion query, I tried by making the list into a list of tuples and directly by adding the elements from the list. But it did not work, and I don't know the best practice for this as I am no SQL shark. I have below added the two different outputs I have before I do the query. I don't know which is easier to work with for this, but the code example is for the list of elements.
Output
['testuser', 'AskeMeyer']
and
[('testuser',), ('AskeMeyer',)]
Code to query
try:
conn = psycopg2.connect(host=ENDPOINT, port=PORT, database=DBNAME, user=USER, password=PASS, sslmode='require', sslrootcert="SSLCERTIFICATE")
cur = conn.cursor()
var_string = ', '.join(map(str, res))
sql = 'INSERT INTO users_from_group(name) VALUES %s;' % var_string)
cur.execute(sql)
error from above
Database connection failed due to syntax error at or near ")"
You need to use brackets and quotes in your insert statement, for example:
var_string = ', '.join([f"(\"{name}\")" for name in ['testuser', 'AskeMeyer']])
Also, there is a bracket at the end of your sql statement which causes the syntax error:
sql = 'INSERT INTO users_from_group(name) VALUES %s;' % var_string)
Should be
sql = 'INSERT INTO users_from_group(name) VALUES %s;' % var_string
it's not the proper way to store lists.
you should save it as json :
json.dumps(['testuser', 'AskeMeyer'] )
then save it
Try this:
var_string = '(' + ','.join(map(str, res)) + ')'
sql = 'INSERT INTO users_from_group(name) VALUES %s;' % var_string

Chinese character insert issue

I have the following dataframe in pandas
need to insert all value into a datawarehouse with chinese characters but chinese characters are instered as junk (?????) (百å¨è‹±åšï¼ˆèˆŸå±±ï¼‰å•¤é…’有é™å…¬å¸
) like above one
The insert query is prepared dynamically.
I need help on how to handle the following scenerio:
Read file as UTF-8 and writte into a datawarehouse using pyodbc connection using character set UTF-8.
df=pd.read_csv(filename,dtype='str',encoding='UTF-8')
cnxn = database_connect() ##Connect to database##
cnxn.setencoding(ctype=pyodbc.SQL_CHAR, encoding='UTF-8')
cnxn.autocommit = True
cursor = cnxn.cursor()
for y in range(len(df)):
inst='insert into '+tablename+' values ('
for x in range(len(clm)):
if str(df.iloc[y,x])=='nan':
df.iloc[y,x]=''
if x!=len(clm)-1:
inst_val=inst_val+"'"+str(df.iloc[y,x]).strip().replace("'",'')+"'"+","
else:
inst_val=inst_val+"'"+str(df.iloc[y,x]).strip().replace("'",'')+"'"+")"
inst=inst+inst_val #########prepare insert statment from values inside in-memory data###########
inst_val=''
print("Inserting value into table")
try:
cursor.execute(inst) ##########Execute insert statement##############
print("1 row inserted")
except Exception as e:
print (inst)
print (e)
same like value should inserted into sql datawarehouse
You are using dynamic SQL to construct string literals containing Chinese characters, but you are creating them as
insert into tablename values ('你好')
when SQL Server expects Unicode string literals to be of the form
insert into tablename values (N'你好')
You would be better off to use a proper parameterized query to avoid such issues:
sql = "insert into tablename values (?)"
params = ('你好',)
cursor.execute(sql, params)

How to fix Python putting wrong value in MySQL database

I am trying to add the value to MySQL database using Python, but for some reason it puts different number than it should.
I tried many syntax and look for help online but no luck. I am using mysql.connector, Python 3.7.
I expected the output:
(12, 'TEST_JOB', 'SOME_TESTING', '20/7/2019')
but I got:
(12, 'TEST_JOB', 'SOME_TESTING', '0.001415127715205547')
Code:
TODAY = date.today().strftime("%d/%m/%Y")
def add_row_to_database(row = ''):
if row == '': return "This is not gonna happened, wrong row"
query = f"INSERT INTO my_table (col1, col2, col3) VALUES (%s, %s, {TODAY})"
cursor.execute(query, row)
connection.commit()
add_row_to_database('TEST_JOB', 'SOME_TESTING')
Answer from #furas solved the problem.
you should use ' ' like in '12345' - '{TODAY}'. If you don't use ' ' then date 20/7/2019 is treated by SQL as division which gives result 0.001415127715205547

How to Insert csv files to database using python_ columns

This is my code
import pymysql
import csv
conn=pymysql.connect("localhost", "root","****","finance")
cursor=conn.cursor()
print "done"
csv_data = csv.reader(file('naver_loan_output.csv'))
for row in csv_data:
cursor.execute('INSERT INTO 'daily_new' (date,cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond )' 'VALUES("%s", "%s", "%s", "%s", "%s", "%s")',row)
conn.commit()
cursor.close()
print "Done"
And this is the error:
File "D:\dropbox\Dropbox\lab\7_0218\insert_daily_new.py", line 13
cursor.execute('INSERT INTO 'daily_new' (date,cust_bal, cust_credit,
fund_stock, fund_hyb, fund_bond )' 'VALUES("%s", "%s", "%s", "%s",
"%s", "%s")',row)
^ SyntaxError: invalid syntax [Finished in 0.104s]
I tried a lot, but I'm not sure about the proper SQL insert query syntax. How do I get columns from csv? There are 6 columns in my csv file.
With this updated example, code works:
import pymysql
import csv
csv_data= csv.reader(file('naver_loan_output.csv'))
conn=pymysql.connect("localhost","finance")
cursor=conn.cursor()
print "Done"
for row in csv_data:
#cursor.execute('INSERT INTO \'daily_new\' (date, cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond ) VALUES({}, {}, {}, {}, {}, {})'.format(row[0], row[1], row[2], row[3], row[4], row[5]))
sql="INSERT INTO daily_n (date,cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond ) VALUES('2017-01-01','2','2','2','2','2')"
cursor.execute(sql)
conn.commit()
cursor.close()
So, I think the for row or %s is the problem.
Mainly, your quotes is the issue.
You need to escape single quotes if larger sql string is wrapped in single quotes; or simply wrap larger string in double quotes like your updated example. And note: the SyntaxError is a Python compile error (not MySQL runtime exception).
For parameterized queries, do not quote the placeholder, %s.
MySQL (and practically for all RDMS's) do not use single quotes to enclose table and column name references as you do with 'daily_new'. Use backticks for names in MySQL. A few databases and the ANSI standard allows the double quote for object identifiers (not string literals).
Consider the following adjustment with a more efficient read process of csv file using with() as opposed to all at once as you have it with file(). And as shown with parameterization, you can prepare the sql statement once and then just bind values iteratively in loop.
strSQL = "INSERT INTO `daily_new` (`date`, cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond )" + \
" VALUES(%s, %s, %s, %s, %s, %s)"
with open('naver_loan_output.csv', 'r') as f:
csv_data = csv.reader(f)
for row in csv_data:
cursor.execute(strSQL, row)
conn.commit()
cursor.close()
conn.close()
print "Done"
I think that you can try something like this:
query = """'INSERT INTO 'daily_new' (date,cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond )' 'VALUES("""+row+""")'"""
cursor.execute(query)
Just see this code fragment from CSV File Reading and Writing doc:
>>> import csv
>>> with open('eggs.csv', 'rb') as csvfile:
... spamreader = csv.reader(csvfile, delimiter=' ', quotechar='|')
... for row in spamreader:
... print ', '.join(row)
Spam, Spam, Spam, Spam, Spam, Baked Beans
Spam, Lovely Spam, Wonderful Spam
I hope it is useful to you or that puts you in the way.
There are three problems tripping you up:
String escape characters
In your code is that the single quote before daily_new is stopping the string and python is interpreting daily_new as a variable, which is not defined.
To solve this you should use the escape character "\" directly before each single quote you want in the string like this:
cursor.execute('INSERT INTO \'daily_new\' (date,cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond ) VALUES("%s", "%s", "%s", "%s", "%s", "%s")',row)
Column access
The csv module returns rows as a list. To access an element in a list (or row in your case), use bracket notation. For row[0] accesses the first element (column) in a row, and row[5] accesses the 6th column.
String substitution
The third problem you are facing is how to pass the values into the string substitution correctly. While there are many ways to do this, an easy one is the format() method. For example: if I wanted to build a string that says "Count is 1", I could run "Count is {}".format(1).
In your case you want to add 6 values to the string, so you add a pair of {} wherever you want a value substituted into a string and add another parameter to the format() function.
Putting it all together
So, to correct your loop code you would want something like this:
csv_data = csv.reader(file('naver_loan_output.csv'))
for row in csv_data:
cursor.execute('INSERT INTO daily_new (date, cust_bal, cust_credit, fund_stock, fund_hyb, fund_bond ) VALUES ({}, {}, {}, {}, {}, {})'.format(row[0], row[1], row[2], row[3], row[4], row[5]))

Using a Python dict for a SQL INSERT statement

I am trying to use a dict to do a SQL INSERT. The logic would basically be:
INSERT INTO table (dict.keys()) VALUES dict.values()
However, I am having a tough time figuring out the correct syntax / flow to do this. This is what I currently have:
# data = {...}
sorted_column_headers_list = []
sorted_column_values_list = []
for k, v in data.items():
sorted_column_headers_list.append(k)
sorted_column_values_list.append(v)
sorted_column_headers_string = ', '.join(sorted_column_headers_list)
sorted_column_values_string = ', '.join(sorted_column_values_list)
cursor.execute("""INSERT INTO title (%s)
VALUES (%s)""",
(sorted_column_headers_string, sorted_column_values_string))
From this I get a SQL exception (I think related to the fact that commas are also included in some of the values that I have). What would be the correct way to do the above?
I think the comment on using this with MySQL is not quite complete. MySQLdb doesn't do parameter substitution in the columns, just the values (IIUC) - so maybe more like
placeholders = ', '.join(['%s'] * len(myDict))
columns = ', '.join(myDict.keys())
sql = "INSERT INTO %s ( %s ) VALUES ( %s )" % (table, columns, placeholders)
# valid in Python 2
cursor.execute(sql, myDict.values())
# valid in Python 3
cursor.execute(sql, list(myDict.values()))
You're not getting escaping on the columns though, so you might want to check them first....
See http://mail.python.org/pipermail/tutor/2010-December/080701.html for a more complete solution
You want to add parameter placeholders to the query. This might get you what you need:
qmarks = ', '.join('?' * len(myDict))
qry = "Insert Into Table (%s) Values (%s)" % (qmarks, qmarks)
cursor.execute(qry, myDict.keys() + myDict.values())
Always good answers here, but in Python 3, you should write the following:
placeholder = ", ".join(["%s"] * len(dict))
stmt = "insert into `{table}` ({columns}) values ({values});".format(table=table_name, columns=",".join(dict.keys()), values=placeholder)
cur.execute(stmt, list(dict.values()))
Don't forget to convert dict.values() to a list because in Python 3, dict.values() returns a view, not a list.
Also, do NOT pour the dict.values() in stmt because it tears a quote out of a string by joining it, which caused MySQL error in inserting it. So you should always put it in cur.execute() dynamically.
I'm a little late to the party but there is another way that I tend to prefer since my data is usually in the form of a dict already. If you list the bind variables in the form of %(columnName)s you can use a dictionary to bind them at execute. This partially solves the problem of column ordering since the variables are bound in by name. I say partially because you still have to make sure that the columns & values portion of the insert are mapped correctly; but the dictionary itself can be in any order (since dicts are sort of unordered anyway)
There is probably a more pythonic way to achieve all this, but pulling the column names into a list and working off it ensures we have a static ordering to build the columns & values clauses.
data_dict = {'col1': 'value 1', 'col2': 'value 2', 'col3': 'value 3'}
columns = data_dict.keys()
cols_comma_separated = ', '.join(columns)
binds_comma_separated = ', '.join(['%(' + item + ')s' for item in columns])
sql = f'INSERT INTO yourtable ({cols_comma_separated}) VALUES ({binds_comma_separated})'
cur.execute(sql, data_dict)
Now whether or not it is a good idea to dynamically build your columns & values clause like this is a topic for a SQL injection thread.
table='mytable'
columns_string= '('+','.join(myDict.keys())+')'
values_string = '('+','.join(map(str,myDict.values()))+')'
sql = """INSERT INTO %s %s
VALUES %s"""%(table, columns_string,values_string)
I tried #furicle's solution but it still inputs everything as a string - if your dict is a mixed one then this may not work as you would want it to. I had a similar issue and this is what I came up with - this is only a query builder and you could use it (with changes) to work with any database of your choice. Have a look!
def ins_query_maker(tablename, rowdict):
keys = tuple(rowdict)
dictsize = len(rowdict)
sql = ''
for i in range(dictsize) :
if(type(rowdict[keys[i]]).__name__ == 'str'):
sql += '\'' + str(rowdict[keys[i]]) + '\''
else:
sql += str(rowdict[keys[i]])
if(i< dictsize-1):
sql += ', '
query = "insert into " + str(tablename) + " " + str(keys) + " values (" + sql + ")"
print(query) # for demo purposes we do this
return(query) #in real code we do this
This is crude and still needs sanity checks, etc, but it works as intended.
for a dict:
tab = {'idnumber': 1, 'fname': 'some', 'lname': 'dude', 'dob': '15/08/1947', 'mobile': 5550000914, 'age' : 70.4}
running the query I get the following output
results of query generated by the suite
This code worked for me (Python 3):
fields = (str(list(dictionary.keys()))[1:-1])
values = (str(list(dictionary.values()))[1:-1])
sql = 'INSERT INTO Table (' + fields + ') VALUES (' + values + ')'
cursor.execute(sql)
It does rely on the dictionary outputting its keys and values in the same order. I'm unclear if this is always true :)
When constructing queries dynamically it's important to ensure that both identifiers and values are correctly quoted. Otherwise you risk
SQL injection if untrusted data is processed
Errors if the column names require quoting (for example embedded spaces)
Data corruption or errors if values are incorrectly quoted (for example 2021-07-11 unquoted may be evaluated as 2003)
Quoting values is best delegated to the DB-API connector. However connector packages don't always provide a way to quote identifiers, so you may need to do this manually. MySQL uses backticks (`) to quote identifiers.
This code quotes identifiers and values. It works for MySQLdb, mysql.connector and pymysql and works for Python 3.5+.
data = {'col1': val1, 'col2': val2, ...}
# Compose a string of quoted column names
cols = ','.join([f'`{k}`' for k in data.keys()])
# Compose a string of placeholders for values
vals = ','.join(['%s'] * len(data))
# Create the SQL statement
stmt = f'INSERT INTO `tbl` ({cols}) VALUES ({vals})'
# Execute the statement, delegating the quoting of values to the connector
cur.execute(stmt, tuple(data.values()))
This is based on other answers here, but it uses back ticks around column names for cases in which you are using reserved words as column names and it it ensures that column names only contain letters, numbers, and underscores to thwart SQL injection attacks.
I've also written a similar upsert that works the same way as the insert but which overwrites data that duplicates the primary key.
import mysql.connector
import re
cnx = mysql.connector.connect(...)
def checkColumnNames(data):
for name in data.keys():
assert re.match(r'^[a-zA-Z0-9_]+$',name), "Bad column name: " + name
def insert(table, data):
checkColumnNames(data)
assert table, "No table specified"
placeholders = ', '.join(['%s'] * len(data))
columns = '`,`'.join(data.keys())
sql = "INSERT INTO `%s` (`%s`) VALUES (%s);" % (table, columns, placeholders)
cnx.cursor().execute(sql, list(data.values()))
def upsert(table, data):
checkColumnNames(data)
assert table, "No table specified"
placeholders = ', '.join(['%s'] * len(data))
columns = '`,`'.join(data.keys())
updates = '`' + '`=%s,`'.join(data.keys()) + '`=%s'
sql = "INSERT INTO `%s` (`%s`) VALUES (%s) ON DUPLICATE KEY UPDATE %s" % (table, columns, placeholders, updates)
cnx.cursor().execute(sql, list(data.values()) + list(data.values()))
Example usage
insert("animals", {
"id": 1,
"name": "Bob",
"type": "Alligator"
})
cnx.commit()
I used this thread for my usage and tried to keep it much simpler
ins_qry = "INSERT INTO {tablename} ({columns}) VALUES {values};" .format(
tablename=my_tablename,
columns=', '.join(myDict.keys()),
values=tuple(myDict.values())
)
cursor.execute(ins_qry)
Make sure to commit the data inserted, either using db_connection.commit() and use cursor.lastrowid, if you need the primary key of the inserted row
This works for me
cursor.execute("INSERT INTO table (col) VALUES ( %(col_value) )",
{'col_value': 123})
if you have list in which there are number of dictionaries
for example: lst=[d1,d2,d3,d4]
then below one will worked for me:
for i in lst:
placeholders = ', '.join(['%s'] * len(i))
columns = ', '.join(i.keys())
sql = "INSERT INTO %s ( %s ) VALUES ( %s )" % (table, columns, placeholders)
cursor.execute(sql,list(i.values()))
conn.commit()
Note:Dont ever forget to commit otherwise you wont be able to see columns and values inserted in table
columns = ', '.join(str(x).replace('/', '_') for x in row_dict.keys())
values = ', '.join("'" + str(x).replace('/', '_') + "'" for x in row_dict.values())
sql = "INSERT INTO %s ( %s ) VALUES ( %s );" % ("tablename", columns, values)
applicable for python3
Let's say our data is:
data = {
"name" : "fani",
"surname": "dogru",
"number" : 271990
}
This is my shorter version:
tablo = "table_name"
cols = ','.join([f" {k}" for k in data.keys()])
vals = ','.join([f"'{k}'" for k in data.values()])
stmt = f'INSERT INTO {tablo} ({cols}) VALUES ({vals})'
What about:
keys = str(dict.keys())
keys.replace('[', '(')
keys.replace(']', ')')
keys.replace("'",'')
vals = str(dict.values())
vals.replace('[', '(')
vals.replace(']', ')')
cur.execute('INSERT INTO table %s VALUES %s' % (keys, vals))
For python 3:
keys = str(dict.keys())[9:].replace('[', '').replace(']', '')
vals = str(dict.values())[11:].replace('[', '').replace(']', '')
...

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