I have this situation where I created a method that will insert rows in database. I provide to that method columns, values and table name.
COLUMNS = [['NAME','SURNAME','AGE'],['SURNAME','NAME','AGE']]
VALUES = [['John','Doe',56],['Doe','John',56]]
TABLE = 'people'
This is how I would like to pass but it doesn't work:
db = DB_CONN.MSSQL() #method for connecting to MS SQL or ORACLE etc.
cursor = db.cursor()
sql = "insert into %s (?) VALUES(?)" % TABLE
cursor.executemany([sql,[COLUMNS[0],VALUES[0]],[COLUMNS[1],VALUES[1]]])
db.commit()
This is how it will pass query but problem is that I must have predefined column names and that's not good because what if the other list has different column sort? Than the name will be in surname and surname in name.
db = DB_CONN.MSSQL() #method for connecting to MS SQL or ORACLE etc.
cursor = db.cursor()
sql = 'insert into %s (NAME,SURNAME,AGE) VALUES (?,?,?)'
cursor.executemany(sql,[['John','Doe',56],['Doe','John',56]])
db.commit()
I hope I explained it clearly enough.
Ps. COLUMNS and VALUES are extracted from json dictionary
[{'NAME':'John','SURNAME':'Doe','AGE':56...},{'SURNAME':'Doe','NAME':'John','AGE':77...}]
if that helps.
SOLUTION:
class INSERT(object):
def __init__(self):
self.BASE_COL = ''
def call(self):
GATHER_DATA = [{'NAME':'John','SURNAME':'Doe','AGE':56},{'SURNAME':'Doe','NAME':'John','AGE':77}]
self.BASE_COL = ''
TABLE = 'person'
#check dictionary keys
for DATA_EVAL in GATHER_DATA:
if self.BASE_COL == '': self.BASE_COL = DATA_EVAL.keys()
else:
if self.BASE_COL != DATA_EVAL.keys():
print ("columns in DATA_EVAL.keys() have different columns")
#send mail or insert to log or remove dict from list
exit(403)
#if everything goes well make an insert
columns = ','.join(self.BASE_COL)
sql = 'insert into %s (%s) VALUES (?,?,?)' % (TABLE, columns)
db = DB_CONN.MSSQL()
cursor = db.cursor()
cursor.executemany(sql, [DATA_EVAL.values() for DATA_EVAL in GATHER_DATA])
db.commit()
if __name__ == "__main__":
ins = INSERT()
ins.call()
You could take advantage of the non-random nature of key-value pair listing for python dictionaries.
You should check that all items in the json array of records have the same fields, otherwise you'll run into an exception in your query.
columns = ','.join(records[0].keys())
sql = 'insert into %s (%s) VALUES (?,?,?)' % (TABLE, columns)
cursor.executemany(sql,[record.values() for record in records])
References:
https://stackoverflow.com/a/835430/5189811
Related
I am trying to create a method in python insert records into a table passing in a list of column names, and an associated list of records.
I was able to set it up where the column names populated dynamically via a for loop, but I can't figure out how to do the same thing with values because the psycopg2.executemany function relies on having %s's as placeholders.
Is it possible to have the number of %s's in the string populate dynamically via a loop? Is there another way to do this?
def load_table(dbname,table_name,fields,records):
try:
#Variable Qty Column Loop
sql_fields = []
for i in fields:
i = sql.Identifier(i)
sql_fields.append(i)
#Need similar loop to replace %s values
#Replace (%s,%s,%s) ???
#.....
#.....
sql_values = []
for i in fields:
sql_values.append('%s')
print(sql_values)
flist = sql.SQL(',').join(sql_fields)
connection, cursor = create_connection(dbname)
insert_query = sql.SQL('INSERT INTO {table_name} ({fields}) VALUES (%s,%s,%s)').format(
table_name = sql.Identifier(table_name),
fields = flist,
cursor.executemany(insert_query,records)
print('Records Loaded Successfully')
except (Exception,psycopg2.Error) as error:
print("Failed to insert record into table {error}".format(error = error))
finally:
# closing database connection.
if (connection):
close_connection(connection,cursor)
You can use sql.Placeholder, to populate the sql statement with the amount of %s-placeholders you need:
def load_table(dbname,table_name,fields,records):
con, cur = create_connection('foo')
query = sql.SQL("insert into {} ({}) values ({})").format(
sql.Identifier(table_name),
sql.SQL(', ').join(map(sql.Identifier, fields)),
sql.SQL(', ').join(sql.Placeholder() * len(fields)))
print(query.as_string(con))
if __name__ == '__main__':
dbname = '...'
table_name = 'messages'
fields = ['user_id', 'message_type', 'message_title']
records = [['12345', 'json', 'my first message'], ]
load_table(dbname,table_name,fields,records)
Output:
insert into "messages" ("user_id", "message_type", "message_title") values (%s, %s, %s)
I have an ever growing and changing database that reflects a permits passed by the State and EPA.
As the database changes and updates I need to transfer the relevant information.
The script does two things; first it checks which fields are the same and creates a list of fields and data that will be inserted into the new database. Second to insert the data into the new database.
Problem is I cannot get it to insert. I have matched everything like it says online in various ways but i get error ('42000', '[42000] [Microsoft][ODBC Microsoft Access Driver] Syntax error in INSERT INTO statement. (-3502) (SQLExecDirectW)').
I cannot figure out how to prevent it.
Code:
import pyodbc
importDatabase = r"J:\ENVIRO FIELD\AccessDatabases\MS4\MS4 Town Databases\~Template\MS4_Apocalypse Import DEV 1.accdb"
"Create the Import Database Connection"
connectionImport = pyodbc.connect(r'Driver={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=%s;' %(importDatabase))
cursorImport = connectionImport.cursor()
"####---Outfall Section---####"
"Import the outfall names into the new database"
tbl = "tbl_Outfall_1_Profile"
exportList = []
importList = []
for row in cursorImport.columns(table = "tblExportMigration_Outfall_1_Profile"):
field = row.column_name
exportList.append(field)
for row in cursorImport.columns(table = "tbl_Outfall_1_Profile"):
field = row.column_name
importList.append(field)
matchingList = []
for field in exportList:
if field != "outfallID":
if field in importList:
matchingList.append(field)
else:
continue
sqlValue = ""
for field in matchingList:
sqlValue += "[%s], " %(field)
sqlValue = sqlValue[:-2]
sql = "SELECT %s from %s" %(sqlValue, "tblExportMigration_Outfall_1_Profile")
for rowA in cursorImport.execute(sql):
tupleList = list(rowA)
tupleList = ["" if i == None else i for i in tupleList]
tupleValues = tuple(tupleList)
sqlUpdate = """INSERT INTO tbl_Outfall_1_Profile (%s) Values %s;""" %(sqlValue, tupleValues)
cursorImport.execute(sqlUpdate)
cursorImport.close()
This is the sql string I create
"INSERT INTO tbl_Outfall_1_Profile ([profile_OutfallName], [profile_HistoricalName1], [profile_HistoricalName2], [profile_HistoricalName3], [profile_HistoricalName4]) Values ('756', '', '', '', '');"
Taking what #Gord Thompson said I was actually able to create a dynamic parameter flow
First created a module to create the ?
def Defining_Paramters(length):
parameterString = ""
for x in range(1,length):
parameterString += "?, "
parameterString += "?"
return parameterString
Then stuck it into the string for the sql update
sqlUpdate = sqlUpdate = "INSERT INTO %s (%s) Values (%s);" %(table, sqlFrameworkSubStr, parameters)
Run the cursor and commit it
cursorTo.execute(sqlUpdate, (dataTuple))
connectionTo.commit()
It would seem that you have to create the query in its entirety then have your data in tuple format for entry
This is the sql string [I think] I create
Try this:
sqlUpdate = """INSERT INTO tbl_Outfall_1_Profile (%s) Values (%s);""" %(sqlValue, tupleValues)
or perhaps:
sqlUpdate = "INSERT INTO tbl_Outfall_1_Profile (%s) Values (%s);" %(sqlValue, tupleValues)
I am trying to create a method in python insert records into a table passing in a list of column names, and an associated list of records.
I was able to set it up where the column names populated dynamically via a for loop, but I can't figure out how to do the same thing with values because the psycopg2.executemany function relies on having %s's as placeholders.
Is it possible to have the number of %s's in the string populate dynamically via a loop? Is there another way to do this?
def load_table(dbname,table_name,fields,records):
try:
#Variable Qty Column Loop
sql_fields = []
for i in fields:
i = sql.Identifier(i)
sql_fields.append(i)
#Need similar loop to replace %s values
#Replace (%s,%s,%s) ???
#.....
#.....
sql_values = []
for i in fields:
sql_values.append('%s')
print(sql_values)
flist = sql.SQL(',').join(sql_fields)
connection, cursor = create_connection(dbname)
insert_query = sql.SQL('INSERT INTO {table_name} ({fields}) VALUES (%s,%s,%s)').format(
table_name = sql.Identifier(table_name),
fields = flist,
cursor.executemany(insert_query,records)
print('Records Loaded Successfully')
except (Exception,psycopg2.Error) as error:
print("Failed to insert record into table {error}".format(error = error))
finally:
# closing database connection.
if (connection):
close_connection(connection,cursor)
You can use sql.Placeholder, to populate the sql statement with the amount of %s-placeholders you need:
def load_table(dbname,table_name,fields,records):
con, cur = create_connection('foo')
query = sql.SQL("insert into {} ({}) values ({})").format(
sql.Identifier(table_name),
sql.SQL(', ').join(map(sql.Identifier, fields)),
sql.SQL(', ').join(sql.Placeholder() * len(fields)))
print(query.as_string(con))
if __name__ == '__main__':
dbname = '...'
table_name = 'messages'
fields = ['user_id', 'message_type', 'message_title']
records = [['12345', 'json', 'my first message'], ]
load_table(dbname,table_name,fields,records)
Output:
insert into "messages" ("user_id", "message_type", "message_title") values (%s, %s, %s)
I have two variables to insert in my table.
user_id - int
marks - float
and I am having this data for multiple users like this:
user_ids = (-,-,-,-,-,-,-) **TUPLE**
marks = (-,-,-,-,-,-,-,-) **TUPLE**
I want to insert this data into my table using executemany and I am executing this query in my flask snippet:
con = pymysql.connect(
host=host,
user=user,
password=password,
db=db,
charset=charset,
cursorclass=pymysql.cursors.DictCursor,
port=port,
)
cur = con.cursor()
percs = calcattnonull()
# percs contains list of dictionaries.
# {[<'user_id'>: <'marks'>], [<'user_id'>: <'marks'>]........}
id_ = []
perc_ = []
final = []
for perc in tqdm(percs):
id_.append(perc["user_id"])
perc_.append(perc["att_perc"])
id_ = tuple(id_)
perc_ = tuple(perc_)
final.append(id_)
final.append(perc_)
cur.executemany(
"UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
final,
)
con.commit()
I am getting this error again and again:
TypeError: not all arguments converted during string formatting
Thanks in advance for helping me.
executemany takes an iterable of the same placeholders you would use when calling execute several times.
So if your original query would be
cur.execute(
"UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
(user_id, att_perc),
)
the equivalent executemany would be
cur.executemany(
"UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
[(user_id, att_perc)],
)
So that said, simply
cur.executemany(
"UPDATE dream_offline_calculate SET (user_id,att_percentage) VALUES (?,?)",
[(perc["user_id"], perc["att_perc"]) for perc in percs],
)
should do the trick.
I'm trying to insert dummy data into a mysql database.
The database structure looks like:
database name: messaround
database table name: test
table structure:
id (Primary key, auto increment)
path (varchar(254))
UPDATED 2 method below, and error.
I have a method to try to insert via:
def insert_into_db(dbcursor, table, *cols, **vals):
try:
query = "INSERT INTO {} ({}) VALUES ('{}')".format(table, ",".join(cols), "'),('".join(vals))
print(query)
dbcursor.execute(query)
dbcursor.commit()
print("inserted!")
except pymysql.Error as exc:
print("error inserting...\n {}".format(exc))
connection=conn_db()
insertstmt=insert_into_db(connection, table='test', cols=['path'], vals=['test.com/test2'])
However, this is failing saying:
INSERT INTO test () VALUES ('vals'),('cols')
error inserting...
(1136, "Column count doesn't match value count at row 1")
Can you please assist?
Thank you.
If you use your code:
def insert_into_db(dbcursor, table, *cols, **vals):
query = "INSERT INTO {} ({}) VALUES ({})".format(table,",".join(cols), ",".join(vals))
print(query)
insert_into_db('cursor_here', 'table_here', 'name', 'city', name_person='diego', city_person='Sao Paulo')
Python returns:
INSERT INTO table_here (name,city) VALUES (name_person,city_person)
Now with this other:
def new_insert_into_db(dbcursor, table, *cols, **vals):
vals2 = ''
for first_part, second_part in vals.items():
vals2 += '\'' + second_part + '\','
vals2 = vals2[:-1]
query = "INSERT INTO {} ({}) VALUES ({})".format(table,",".join(cols), vals2)
print(query)
new_insert_into_db('cursor_here', 'table_here', 'name', 'city', name_person='diego', city_person='Sao Paulo')
Python will return the correct SQL:
INSERT INTO table_here (name,city) VALUES ('diego','Sao Paulo')
Generally in Python you pass a parameterized query to the DB driver. See this example in PyMySQL's documentation; it constructs the INSERT query with placeholder characters, then calls cursor.execute() passing the query, and a tuple of the actual values.
Using parameterized queries is also recommended for security purposes, as it defeats many common SQL injection attacks.
you should print the sql statement which you've generated, that makes it a lot easier to see what's wrong.
But I guess you need quotes ' around string values for your ",".join(vals) (in case there are string values.
So your code is producing
insert into test (path,) values (test.com/test2,);
but it should produce
insert into test (`path`) values ('test.com/test2');
Otherwise try https://github.com/markuman/MariaSQL/ which makes it super easy to insert data to MariaDB/MySQL using pymysql.
Change your query as below
query = "INSERT INTO {} ({}) VALUES ('{}')".format(table, ",".join(cols), "'),('".join(vals))
As you are using join, the variable is expected to be a list but not a string
table = 'test'
cols = ['path']
vals = ['test.com/test2', 'another.com/anothertest']
print(query)
"INSERT INTO test (path) VALUES ('test.com/test2'),('another.com/anothertest')"
Update:
def insert_into_db(dbconnection=None, table='', cols=None, vals=None):
mycursor = dbconnection.cursor()
if not (dbconnection and table and cols and vals):
print('Must need all values')
quit()
try:
query = "INSERT INTO {} ({}) VALUES ('{}')".format(table, ",".join(cols), "'),('".join(vals))
mycursor.execute(query)
dbconnection.commit()
print("inserted!")
except pymysql.Error as exc:
print("error inserting...\n {}".format(exc))
connection=conn_db()
insertstmt=insert_into_db(dbconnection=connection, table='test', cols=['path'], vals=['test.com/test2'])