I am trying to send data to PostgreSQL, data is a tuple of strings i.e (time, price).
The problem is when I send data using a simple query (not parametrized) it works fine!
Following is the simple query working perfectly.
cur.execute("INSERT INTO paxos (date,price) VALUES ('2020-04-09 14:39:58.145804', '$1,664.08');");
But as those values aren't fixed, so I want to store them in variable and use a parameterized query for sending data, but the parameterized query isn't working for me. Here is the parameterized query.
cur.execute("INSERT INTO paxos (date, price) values (?, ?)",(time, price))
Here is the complete function I am trying to implement:
def insert_data(time, price):
con = psycopg2.connect(database="", user="", password="", host="", port="5432")
print("Database opened successfully")
cur = con.cursor()
data_tuple = (time, price)
cur.execute("insert into paxos (date, price) values (?, ?)",(time, price))
con.commit()
print("Record inserted successfully")
con.close()
insert_data("2020-04-09 14:39:58.145804", "$1,664.08")
Here is the error message:
It seems like this is a python syntax error. I think you should use the format method of the string object (see codesnippet below).
I can't test it right now, but according to some old code of mine, I always "built" a query string first and then passed the string object to the cursor. Try something like that:
artist = "Aphex Twin"
title = "Windowlicker"
query = '''SELECT EXISTS(SELECT * FROM tracks
WHERE artist ILIKE \'{}\'AND
title ILIKE \'{}\')'''.format(artist, title)
cursor.execute(query)
Related
This connection works, but the result is just the text of the query itself:
Connection = cx_Oracle.connect(user=username, password=password, dsn=dsn, encoding=enc)
query = 'simple select statement'
cursor = Connection.cursor()
cursor.execute(query)
Connection.commit()
cursor.close()
print(query)
The result in the dataframe prints 'SELECT RECV_MBR_ID...' instead of the ID's. What am I missing?
This is not unexpected! You are simply printing the value to which you set that variable! You need to fetch the results. You can do this in one of several ways. I'll show a couple of the more common ones here:
for row in cursor.execute(query):
print(row)
OR
cursor.execute(query)
print(cursor.fetchall())
I am trying to convert my sql query output into a list to look a certain way.
Here is my code:
def get_sf_metadata():
import sqlite3
#Tables I want to be dynamically created
table_names=['AcceptedEventRelation','Asset', 'Book']
#SQLIte Connection
conn = sqlite3.connect('aaa_test.db')
c = conn.cursor()
#select the metadata table records
c.execute("select name, type from sf_field_metadata1 limit 10 ")
print(list(c))
get_sf_metadata()
Here is my output:
[('Id', 'id'), ('RelationId', 'reference'), ('EventId', 'reference')]
Is there any way to make the output looks like this:
[Id id, RelationId reference, EventId reference]
You can try
print(["{} {}".format(i[0], i[1]) for i in list(c)])
That will print you
['Id id', 'RelationId reference', 'EventId reference']
Sorry for this but I'm real new to sqlite: i've created a database from an excel sheet I had, and I can't seem to fetch the values of the column I need
query = """ SELECT GNCR from table"""
cur.execute(query)
This actually works, but
query = """ SELECT ? from table"""
cur.execute(query, my_tuple)
doesn't
Here's my code:
def print_col(to_print):
db = sqlite3.connect('my_database.db')
cur = db.cursor()
query = " SELECT ? FROM my_table "
cur.execute(query, to_print)
results = cur.fetchall()
print(results)
print_col(('GNCR',))
The result is:
[('GNCR',), ('GNCR',), ('GNCR',), ('GNCR',), [...]]
instead of the actual values
What's the problem ? I can't figure it out
the "?" character in query is used for parameter substitution. Sqlite will escape the parameter you passed and replace "?" with the send text. So in effect you query after parameter substitution will be SELECT 'GNCR' FROM my_table where GNCR will be treated as text so you will get the text for each row returned by you query instead of the value of that column.
Basically you should use the query parameter where you want to substitute the parameter with escaped string like in where clause. You can't use it for column name.
I'm converting a postgres script into asyncpg.
im getting "asyncpg.exceptions.PostgresSyntaxError: syntax error at or near "%""
i assume my placeholder format is incorrect but i cant find an example of a correct format.
Original working psycopg2 code:
async def commit_trade_postgres(response_data_input):
conn = await psycopg2.connect(
"dbname='postgres' user='postgres' password = 'postgres123' host='localhost' port= '5432'")
cur = conn.cursor()
cur.execute(
"CREATE TABLE IF NOT EXISTS trade_{symbol} (time timestamptz NOT NULL ,side text, size float, price float, tick_direction text)".format(**response_data_input))
conn.commit()
cur.execute(
"SELECT create_hypertable('trade_{symbol}', 'time', if_not_exists => TRUE)".format(**response_data_input))
conn.commit()
cur.execute("INSERT INTO trade_{symbol} (time, side, size, price, tick_direction) VALUES (now(), %(side)s, %(size)s, %(price)s, %(tick_direction)s)".format(
**response_data_input), (response_data_input))
conn.commit()
print("commited trade")
My attempt as per the example code supplied int he docs:
async def commit_trade_postgres(response_data_input):
conn = await asyncpg.connect(database='postgres', user='postgres', password='postgres123', host='localhost', port='5432')
await conn.execute(
"CREATE TABLE IF NOT EXISTS trade_{symbol} (time timestamptz NOT NULL ,side text, size float, price float, tick_direction text)".format(**response_data_input))
await conn.execute(
"SELECT create_hypertable('trade_{symbol}', 'time', if_not_exists => TRUE)".format(**response_data_input))
await conn.execute("INSERT INTO trade_{symbol} (time, side, size, price, tick_direction) VALUES (now(), %(side)s, %(size)s, %(price)s, %(tick_direction)s)".format(
**response_data_input), (response_data_input))
print("commited trade")
EDIT: Sample Query, Which i'm extracting 'data' as a dict.
response_dict_instrument = {'topic': 'instrument.BTCUSD', 'data': [{'symbol': 'BTCUSD', 'mark_price': 12367.29, 'index_price': 12360.1}]}
You're formatting query by yourself. You never should do that. Also I would suggest you to create table for every incoming symbol beforehand, do not do this dynamically.
Asyncpg template uses $ sign with number to substitute values to query for you. doc
So, syntax should be like this, if input is dictionary.
async def save_input(input):
# create connection
conn = ...
trade_symbol = input['symbol']
query = "create table if not exists trade_{trade_symbol} ... ".format(trade_symbol=trade_symbol) # your column names go here
await conn.execute(query)
query = "SELECT create_hypertable('trade_{trade_symbol} ...".format(trade_symbol=trade_symbol)
await conn.execute(query)
# i'm not copyng your exact keys, you should do it yourself
values = (input['key1'], input['key2'], input['key3'])
query = "insert into trade_{trade_symbol} (key1, key2, key3) values ($1, $2, $3);".format(trade_symbol=trade_symbol)
await conn.execute(query, *values)
await conn.close()
I'm trying to create a code piece that inserts an object I've created to store data in a very specific way into an SQL table as a blob type, and it keeps giving me an ' sqlite3.InterfaceError: Error binding parameter 1 - probably unsupported type.' error.
Has any of you encountered something similar before? Do you have any ideas how to deal with it?
conn = sqlite3.connect('my_database.db')
c = conn.cursor()
params = (self.question_id, i) #i is the object in question
c.execute('''
INSERT INTO '''+self.current_test_name+''' VALUES (?, ?)
''',params)
conn.commit()
conn.close()
For starters, this would be a more appropriate execute statement as it is way cleaner:
c.execute("INSERT INTO "+self.current_test_name+" VALUES (?, ?)", (self.question_id, i))
You are also missing the table you are inserting into (or the columns if self.current_test_name is the table name.)
Also, Is the column in the database setup to handle the data type for the provided input for self.question_id and i? (Not expecting TEXT when you provided INT?)
Example of a working script to insert into a table that has 2 columns named test and test2:
import sqlite3
conn = sqlite3.connect('my_database.db')
c = conn.cursor()
c.execute("CREATE TABLE IF NOT EXISTS test(test INT, test2 INT)")
conn.commit()
for i in range(10):
params = (i, i) # i is the object in question
c.execute("INSERT INTO test (test, test2) VALUES (?, ?)", params)
conn.commit()
conn.close()