Sqlite insert not working with python -

i'm working sqlite3 on python 2.7 , facing problem many-to-many relationship. have table fetching primary key this

current.execute("select extensionid tblextensionlookup extensionname = ?",[ext]) 

and fetching primary key table

current.execute("select hostid tblhostlookup hostname = ?",[host]) 

now doing have third table these 2 keys foreign keys , inserted them this

current.execute("insert tblextensionhistory values(?,?)",[hid,eid]) 

the problem don't know why last insertion not working keeps giving errors. have tried is:

first thought because have autoincrement primary id last mapping table didn't provide, isn't supposed consider it's auto incremented? went ahead , tried adding null,none,0 nothing works.

secondly thought maybe because i'm not getting values tables above tried printing out , shows works.

any suggestions doing wrong here?

edit : when don't provide primary key error as

the table has 3 columns provided 2 values 

and when provide them none,null or 0 says

parameter 0 not supported because of unsupported type 

i tried implementing @abarnet way still keeps saying parameter 0 not supported

connection = sqlite3.connect('webinfrastructurescan.db')     connection:         current = connection.cursor()         current.execute("select extensionid tblextensionlookup extensionname = ?",[ext])         eid = current.fetchone()         print eid         current.execute("select hostid tblhostlookup hostname = ?",[host])         hid = current.fetchone()         print hid          current.execute("insert tblextensionhistory(hostid,extensionid) values(?,?)",[hid,eid]) 

edit 2 :

the database schema :

table 1:

create table tblhostlookup (  hostid integer primary key autoincrement,  hostname text); 

table2:

 create table tblextensionlookup (   extensionid integer primary key autoincrement,   extensionname text); 

table3:

create table tblextensionhistory ( extensionhistoryid integer primary key autoincrement, hostid integer, foreign key(hostid) references tblhostlookup(hostid), extensionid integer, foreign key(extensionid) references tblextensionlookup(extensionid)); 

it's hard sure without full details, think can guess problem.

if use insert statement without column names, values must match columns given in schema. can't skip on of them.*

the right way fix use column names in insert statement. like:

current.execute("insert tblextensionhistory (hostid, extensionid) values (?,?)",                 [hid, eid]) 

now can skip columns want (as long they're autoincrement, nullable, or otherwise skippable, of course), or provide them in order want.

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for second problem, you're trying pass in rows if single values. can't that. code:

eid = current.fetchone() 

this return like:

[3] 

and try bind extensionid column, gives error.

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in future, may want try write , debug sql statements in sqlite3 command-line tool and/or favorite gui database manager (there's simple extension runs in firefox if don't want fancy) , them right, before try getting python right.

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* not true databases. example, in msjet/access, must skip on autoincrement columns. see sqlite documentation how sqlite interprets insert no column names, or similar documentation other databases.