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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

Query regarding python database programming

I am using the below code to delete a row from sqlite table.
def deleteFromTable(item):
conn = sqlite3.connect("lite.db")
cur = conn.cursor()
cur.execute("DELETE FROM store WHERE item=?", (item,))
conn.commit()
conn.close()
Why do i need to use comma after item (item,) while passing the argument?

('String') evaluates into string, but ('string',) evaluates into tuple. that's why you need comma.

Using Python see if Table exists

I have to connect to an Oracle database and see if a table exists. While I can get a list of the tables, I'm having trouble seeing if the table I'm looking for is in the list. Some tables have associated table which I'll have to join on, some do not, thus I have to check.
What is in my list: ('NYSDOH_CI_EI_HOSPITAL',)
sql = "SELECT table_name FROM all_tables"
cur.execute(sql)
searchstr = 'NYSDOH_CI_EI_HOSPITAL'
p = re.compile(searchstr)
#create data array to load in SQL results in.
ciDataSet = []
cxRows = cur.fetchall()
for i in cxRows:
#print i # list of tables
if p.match(str(i)):
print i
It doesn't find it, even if I use a wildcard.

fetchall() returns a list of tuples.
So when you do
for i in cxRows:
'i' is of type tuple. In your case, this tuple will have only single value. You can access it using i[0] and match it with p.
Currently you are converting a tuple to string so regular expression will not match.
Corrected code:
sql = "SELECT table_name FROM all_tables"
cur.execute(sql)
searchstr = 'NYSDOH_CI_EI_HOSPITAL'
p = re.compile(searchstr)
#create data array to load in SQL results in.
ciDataSet = []
cxRows = cur.fetchall()
for i in cxRows:
#print i # list of tables
if p.match(str(i[0])):
print i

To improve on the syntax of #vaichidrewar, you could simplify the fetch loop to:
for tabname, in cur:
if p.match(str(tabname)):
print(tabname)
But it's going to be more efficient to do the reg exp matching in the query:
sql = "select table_name from all_tables where regexp_like(table_name, :tn, 'i')"
searchstr = 'EMP'
cur.execute(sql, (searchstr,))
for tabname, in cur:
print(tabname)
The 'i' option does a case-insensitive match. You can adjust the regexp as you like.

MySQL and PYTHON. How to query an WHERE 'column' IN tuple

I have a tuple of integer, I want to query all rows with column value found within the tuple. It's easy to construct the query, but I want it to be sql injection proof. I normally use prepared statement, but I don't see how to deal with both needs.
My query construction looks like that :
filterList = (1, 2, 4) #Taken as input. Should be integers
sqlRequest = 'SELECT * FROM table'
if filterList != None and len(filterList) > 0:
sqlRequest += ' WHERE column IN ('
addComa = False
for filter in filterList:
if addComa:
sqlRequest += ','
else:
addComa = True
sqlRequest += '%s'%(int(filter)) #casted to int to avoid SQL injection. Still not as good as I would like
sqlRequest += ')'
#At this point sqlRequest == 'SELECT * FROM table WHERE column IN (1,2,4)'
sqlResult = cursor.execute(sqlRequest)
I would love to have a query more like :
sqlRequest = 'SELECT * FROM table WHERE column IN (%s, %s, %s)'
And to execute it with prepared statement :
sqlResult = cursor.execute(sqlRequest, filterList[0], filterList[1], filterList[2])
But filterList as a variable length. Is there any way to do something like?
sqlResult = cursor.execute(sqlRequest, filterList) #where filterList is the whole tuple

You can use string formatting to generate your placeholders:
statement = "SELECT * FROM table WHERE column IN ({0})".format(
', '.join(['%s'] * len(filterList)))
cursor.execute(statement, filterList)
You may still want to test that filterList is not empty, and omit the WHERE clause altogether in that case:
statement = "SELECT * FROM table"
if filterList:
statement += " WHERE column IN ({0})".format(
', '.join(['%s'] * len(filterList)))
cursor.execute(statement, filterList)

you should be able to insert it as a complete string into a mysql in clause like so.
inList = "','".join(str(i) for i in filterList)
inList = r"'%s'" % inList
sqlRequest = 'SELECT * FROM table WHERE column IN (%s)'
sqlResult = cursor.execute(sqlRequest, inList)

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(']', '')
...