double record insertion

I've got the follow problem with this query:

Code:

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QSqlQuery *cola2 = new QSqlQuery( "INSERT INTO preguntas ( pregunta, dificultad, referencia, respuesta ) VALUES ( ?, ?, ?, ? )" );
            cola2->bindValue( 0, c->texto );
            cola2->bindValue( 1, c->dificultad );
            cola2->bindValue( 2, c->referencia );
            cola2->bindValue( 3, c->respuesta );
            if( !cola2->exec() )
            {
               cout<<"agregar_pregunta()::Error al ejecutar la cola de insercion "<<endl;
               cout<<"agregar_pregunta()::Descripcion del error: "<<cola2->lastError().text()<<endl;
               TElog->append( "No se pudo agregar la pregunta a la db" );
            }
            else
            {
               cout<<"agregar_pregunta()::Registro Agregado"<<endl;
               agregadas++;
            }
            delete(cola2);

---

this query is ona cycle for each record that must be inserted... but at doing a export of the table gets one empty record and a good record..
chequed that this query is executed only once in each record insertion.
Thanks in advance...:)

Show us your full cycle

It should be:

Code:

---

QSqlQuery *cola2 = new QSqlQuery();
cola2->prepare( "INSERT INTO preguntas ( pregunta, dificultad, referencia, respuesta ) VALUES ( ?, ?, ?, ? )" );
cola2->bindValue( 0, c->texto );
cola2->bindValue( 1, c->dificultad );
...

---

BTW. Why do you allocate that query on the heap, if you delete it immediately? Won't it be simplier to create it on the stack?

Quote:

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Originally Posted by jacek

It should be:

Code:

---

QSqlQuery *cola2 = new QSqlQuery();
cola2->prepare( "INSERT INTO preguntas ( pregunta, dificultad, referencia, respuesta ) VALUES ( ?, ?, ?, ? )" );
cola2->bindValue( 0, c->texto );
cola2->bindValue( 1, c->dificultad );
...

---

BTW. Why do you allocate that query on the heap, if you delete it immediately? Won't it be simplier to create it on the stack?

---

thanks, the prepare function works fine now. About the deletion it`s necesary because Sqlite block the while db with each query, cursor, o whatever that uses the database.:rolleyes:

Quote:

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Originally Posted by tranfuga25s

About the deletion it`s necesary because Sqlite block the while db with each query, cursor, o whatever that uses the database.

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But if you create that query object on the stack, it will be deleted too and additionally it will be faster and less error-prone.