Question

I use this code to retreive an id. It works:

        db = MySQLdb.connect("localhost","root","","proyectoacademias" )

        cursor = db.cursor()

        sql = "SELECT id FROM test WHERE url=\'"
        sql = sql + self.start_urls[0]
        sql = sql + "\'"

        cursor.execute(sql)

        data = cursor.fetchone()

        for row in data:
            self.id_paper_web=str(row)

        db.close()

It gives me the id of the current row I have to update…

But then I try to update or to insert, it doesn’t work….

    def guardarDatos(self):
    db = MySQLdb.connect("localhost","root","","proyectoacademias" )

    cursor = db.cursor()

    sql = "UPDATE test SET abstract=\'"+str(self.abstracto)+"\', fecha_consulta=\'"+str(self.fecha_consulta)+"\', anio_publicacion=\'"+str(self.anio_publicacion)+"\', probabilidad="+str(self.probabilidad)+" WHERE id = "+str(self.id_paper_web)

    print "\n\n\n"+sql+"\n\n\n"
    cursor.execute(sql)      

    for i in range (len(self.nombres)):
        sql = "INSERT INTO test_autores VALUES (\'"+self.nombres.keys()[i]+"\', "+str(self.id_paper_web)+", \'"+self.instituciones[self.nombres[self.nombres.keys()[i]]]+"\', "+str((i+1))+")"
        print "\n\n\n"+sql+"\n\n\n"
        cursor.execute(sql)

    db.close()

I print every sql query I sent and they seem to be fine… no exceptions thrown, just no updates or inserts in the database…

Answer 1

you must commit … or set the db to auto commit

db.commit()

lots of py sqlite3 tutorials out there

By default, the sqlite3 module opens transactions implicitly before a
Data Modification Language (DML) statement (i.e.
INSERT/UPDATE/DELETE/REPLACE), and commits transactions implicitly
before a non-DML, non-query statement (i. e. anything other than
SELECT or the aforementioned).

So if you are within a transaction and issue a command like CREATE
TABLE …, VACUUM, PRAGMA, the sqlite3 module will commit implicitly
before executing that command. There are two reasons for doing that.
The first is that some of these commands don’t work within
transactions. The other reason is that sqlite3 needs to keep track of
the transaction state (if a transaction is active or not).

You can control which kind of BEGIN statements sqlite3 implicitly
executes (or none at all) via the isolation_level parameter to the
connect() call, or via the isolation_level property of connections.

If you want autocommit mode, then set isolation_level to None.

Otherwise leave it at its default, which will result in a plain
“BEGIN” statement, or set it to one of SQLite’s supported isolation
levels: “DEFERRED”, “IMMEDIATE” or “EXCLUSIVE”.

• http://docs.python.org/library/sqlite3.html Section 11.13.6