Sqlite3.ProgrammingError: cannot work with a closed database. (python / sqlite)

Question

I use a generic function to execute all sqlite queries in a class. Everything works until I use a for loop with more than one item in the list.

Here's a generic function that executes SQL queries:

def executeQuery(self, query, params = ()):
        results = {}
        try:
            cur = self.conn.cursor()
            cur.execute(query, params)
            self.conn.commit()
            rows = cur.fetchall()

            results['status'] = 'success'
            result = []
            if rows:
                column = map(lambda x: x[0], cur.description)
                for row in rows:
                    result.append( dict(zip(column, row)) )

            results['results'] = result

        except self.conn.Error, e:
            if self.conn:
                self.conn.rollback()

            print "Error: %s" % e.args[0]
            results['status'] = 'failure'
            results['results'] = e.args[0]

        finally:
            if self.conn:
                self.conn.close()

        return results

And here is the loop that causes me an error with a closed database:

stages = self.getStageByDate(2000)
        for stage in stages['results']:
            print stage['name']
            additives = self.getStageAdditives(stage['name'])
            print additives
            for additive in additives['results']:
                print additive

The error seems to come from "getStageAdditives ()" because it returns 4 elements, and "getStageByDate ()" returns only 1.

It seems to me that the database connection does not close before trying a second connection. Why is this happening? This did not happen when used with a MySQL database. What are the solutions to this problem?

Answer 1

" , ", " " . , , , (__init__) not-show-in-your-example, execute_query.

( ) conn __init__, . .

.close(), .commit() . finally, try. , ( ), ( , ).

.close() , , , .close() , . finally .

Answer 2

- ? ? , , executeQuery, , .

Answer 3

Remove this from code

 self.conn.close()

It will solve the problem, because when you want to get information from a database, you cannot write

conn.Close ()