as mentioned in the title i get this error when i try to execute a prepared statement. The full error is:
RuntimeError: No matching overloads found for prepareStatement in find. at native\common\jp_method.cpp:127
As far as i can understand is, that propably that since i am trying to use a prepared statement, that the compiler can not find something to overload the ? placeholder.
Code snippet:
curs = self.dbconn.cursor()
sqlLogin = ("SELECT name,email FROM BENUTZER where name=? and email=?", ( benutzerObjekt.name,benutzerObjekt.email))
curs.execute(sqlLogin)
The error seems to happen at curs.execute(sqlLogin), which is shown to me in the traceback when debugging.
I'm trying to use the input of an html input, which is stored in benutzerObjekt.name and benutzerObjekt.email as input for the select SQL statement. So most probably something is wrong with either my SQL statement, or the execution of the statement, which is underlined when debugging. I am using db2.
Thanks in advance!
You need to pass parameters as second argument in cursor.execute. Right now your query is a nested tuple of two items with first being a string and second item being a tuple of two values.
Consider separating the arguments for function call:
curs = self.dbconn.cursor()
# SINGLE STRING VALUE
sqlLogin = "SELECT name,email FROM BENUTZER WHERE name=? AND email=?"
# TUPLE OF TWO VALUES
vals = (benutzerObjekt.name, benutzerObjekt.email)
# PASS SQL AND PARAMS SEPARATELY
curs.execute(sqlLogin, vals)
Alternatively, you can unpack your nested tuple using asterisk, *:
sqlLogin = (
"SELECT name,email FROM BENUTZER where name=? and email=?",
(benutzerObjekt.name, benutzerObjekt.email)
)
curs.execute(*sqlLogin)
Related
I'm having a problem executing this SQL statement with a python list injection. I'm new to teradata SQL, and I'm not sure if this is the appropriate syntax for injecting a list into the where clause.
conn = teradatasql.connect(host='PROD', user='1234', password='1234', logmech='LDAP')
l = ["Comp-EN Routing", "Comp-COLLABORATION"]
l2 = ["PEO", "TEP"]
l3 = ["TCV"]
crsr = conn.cursor()
query = """SELECT SOURCE_ORDER_NUMBER
FROM DL_.BV_DETAIL
WHERE (LEVEL_1 IN ? AND LEVEL_2 IN ?) or LEVEL_3 IN ?"""
crsr.executemany(query, [l,l2,l3])
conn.autocommit = True
I keep getting this error
Version 17.0.0.2] [Session 308831600] [Teradata Database] [Error 3939] There is a mismatch between the number of parameters specified and the number of parameters required.
Late to answer this, but if I found the question someone else will in the future too.
executemany in teradatasql requires that second parameter to be a "sequence of sequences". The most common type of sequence we generally use in Python is a list. Essentially you need a list that contains, for each element in the list, a list.
In your case this may look like:
myListOfLists=[['level1valueA','level1valueA','level3valueA'],['level1valueB','level1valueB','level3valueB']]
Your SQL statement will be executed twice, once for each list in your list.
In your case though I suspect you are wanting to find any combination of the values that you have stored in your three lists which is entirely different ball of wax and is going to take some creativity (generate a list of list with all possible combinations and submit to executemany OR construct a SQL statement that can take in multiple comma delimited lists of values, form a cartesian product, and test for hits)
Want to add some regarding SELECT statement and executemany method: to retrieve all records returned by your query you will need to call .nextset() followed by .fetchall() as many times as it will become False. First .fetchall() will give you only first result (first list of parameters specified).
...
with teradatasql.connect(connectionstring) as conn:
with conn.cursor() as cur:
cur.executemany("SELECT COL1 FROM THEDATABASE.THETABLE WHERE COL1 = ?;",[['A'],['B']])
result=cur.fetchall() # will bring you only rows matching 'A'
if (cur.nextset()):
result2=cur.fetchall() # results for 'B'
...
im new in programing, starting with python
I found this script in a post (link below)
query = 'SELECT * FROM {}'.format(table)
c.execute(query)
How to use variable for SQLite table name
it worked, but now i have to add some complexity and dont know how...
i had this befour:
def add(order, theme):
parameters = [order, theme]
c.execute("INSERT INTO TABLE_NAME VALUES(NULL, ?,?)", parameters)
so im trying have the same, but with de name of the table free to choose.
trying things like this, but dont really know the syntax for it:
def add(order, theme):
table = input("with what table do you want to work with? ")
parameters = [order, theme]
insert = 'INSERT INTO {} VALUES(NULL, ?,?)'.format(table, parameters)
c.execute(insert)
i suspected it woudnt work Hope you can help! :)
The following line substitutes {} with the contents of the variable table and stores the result in the variable query. format works with any string:
query = 'SELECT * FROM {}'.format(table)
On the other hand the kind of substitution done by c.execute replaces the ? in the string with the values in the list parameters:
c.execute("INSERT INTO TABLE_NAME VALUES(NULL, ?,?)", parameters)
You could combine them both to achieve the effect you want:
table = input("with what table do you want to work with? ")
query = 'INSERT INTO {} VALUES(NULL, ?, ?)'.format(table)
parameters = [order, theme]
c.execute(query, parameters)
You are mixing things.
Format is a method of Python string object used to generate dynamically your string based on variables from your code. In your first example is correct to define the name of the database.
Questions marks as a placeholder for the values of your query is proper of SQL and must be used without format as you did in the second example.
To fix your code, first build the string template of the query using format to define the databasename. Then, execute the resultant string with execute and passing the arguments targeting the question marks.
I am trying to do a simple query in Python with mysql and I have this error and I don't know why I have this error:
ValueError: Could not process parameters
What I am doing is this:
mycursor = mydb.cursor()
sql="SELECT pathFile FROM googlesearch where tweetid=%d LIMIT 1"
print(lastid)
print(sql)
mycursor.execute(sql,(lastid),)
mydb.commit()
myresult = mycursor.fetchall()
print(myresult)
Why I have this error?. It is a simple query as you can see. Thanks
add a comma in the line:
mycursor.execute(sql,(lastid),)
(lastid,) is a tuple, but (lastid) is not.
So use mycursor.execute(sql,(lastid,),) instead (note the comma after lastid)
for futher reference check the docs here:
It says:
Note:
In Python, a tuple containing a single value must include a comma. For example, ('abc') is evaluated as a scalar while ('abc',) is evaluated as a tuple.
Working with a newly purchased RaspberryPi and I am very new to Python/MySQL so please excuse the naive question I am posting.
I have looked at many Q&A's about this but I cannot seem to get my head around 'why' this is failing. I get error: "must be string or read-only buffer, not tuple". My variable appears as a string if I test it with TYPE so now I am lost.
import MySQLdb
import time
db = MySQLdb.connect(host="localhost", user="user",passwd="easypwd", db="imagepi")
cursor = db.cursor()
current_time = time.strftime("%H:%M:%S")
current_date = time.strftime("%Y-%m-%d")
filename = (current_time+'.jpg')
sql = ("""INSERT INTO imagelocator(batch, date, time, filename) VALUES
('1001', current_date, current_time, %s)""", filename)
cursor.execute(sql)
db.commit()
db.close()
Thanks so much for offering me a little push in the right direction.
The sql variable is a tuple. One half of it is your SQL statement, and the other half is the token value for the %s parameter in your statement. However, simply passing a tuple to an argument does not break it apart and use each element in the tuple as a separate parameter. For that, you have to use an asterisk: function_to_call(*tuple_args) ... but I think you'll have a problem with that, as well, since the database cursor expects a string for the statement argument, and a sequence for the parameters argument. The parameters argument must be a sequence (tuple, list, set, etc.) even if there is only one value.
TL;DR - You need to do something more like this:
sql = "INSERT INTO table_name (a_column, b_column) VALUES ('asdf', %s)"
args = (filename,)
cursor.execute(sql, args)
... or, if you really wanted to be tricksy and use a tuple for everything:
sql = ("INSERT INTO table_name (a_column, b_column) VALUES ('asdf', %s)", (filename,))
cursor.execute(*sql)
Edit: I guess I didn't clarify... while enclosing a string with parentheses does not create a tuple, the addition of a comma does. So, (string_var) is not a tuple, while (string_var,) is. Hopefully, that removes any confusion with how the above code operates.
Also, here's some documentation on the asterisk stuff; both the boring official docs and an easier-to-understand blog post:
Boring Python docs
Blog post
I'm trying execute a simple query, but getting this error no matter how I pass the parameters.
Here is the query (I'm using Trac db object to connect to a DB):
cursor.execute("""SELECT name FROM "%s".customer WHERE firm_id='%s'""" % (schema, each['id']))
schema and each['id'] both are simple strings
print("""SELECT name FROM "%s".customer WHERE firm_id='%s'""" % (schema, each['id']))
Result:
SELECT name FROM "Planing".customer WHERE firm_id='135'
There is on error is a remove quote after firm_id=, but that way parameter is treated a an integer and ::text leads to the very same error.
In my case I didn't realize that you had to pass a tuple to cursor.execute. I had this:
cursor.execute(query, (id))
But I needed to pass a tuple instead
cursor.execute(query, (id,))
I got this same error and couldn't for the life of me work out how to fix, in the end it was my mistake because I didn't have enough parameters matching the number of elements in the tuple:
con.execute("INSERT INTO table VALUES (%s,%s,%s,%s,%s)",(1,2,3,4,5,6))
Note that I have 5 elements in the values to be inserted into the table, but 6 in the tuple.
It is recommended to not use string interpolation for passing variables in database queries, but using string interpolation to set the table name is fine as long as it's not an external input or you restrict the allowed value. Try:
cursor.execute("""
SELECT name FROM %s.customer WHERE firm_id=%%s
""" % schema, (each['id'],))
Rules for DB API usage provides guidance for programming against the database.
Use AsIs
from psycopg2.extensions import AsIs
cursor.execute("""
select name
from %s.customer
where firm_id = %s
""",
(AsIs(schema), each['id'])
)
You could try this:
cursor.execute("INSERT INTO table_name (key) VALUES(%s)",(value1,))
You will get an error if you are missing a (,) after value1.
The correct way to pass variables in a SQL command is using the second argument of the execute() method. And i think you should remove single quotes from second parameter, read about it here - http://initd.org/psycopg/docs/usage.html#the-problem-with-the-query-parameters.
Note that you cant pass table name as parameter to execute and it considered as bad practice but there is some workarounds:
Passing table name as a parameter in psycopg2
psycopg2 cursor.execute() with SQL query parameter causes syntax error
To pass table name try this:
cursor.execute("""SELECT name FROM "%s".customer WHERE firm_id=%s""" % (schema, '%s'), (each['id'],))
Every time I have this kind of error, I am passing the wrong amount of values. Try check it