How to output the concrete contents of a QsqlQuery before execution - sql

Question

For debuging prurpose I wouls like to print a sql query I am executing.
Here is my code:
QSqlQuery query;
query.prepare("INSERT INTO GeoAndEnergies VALUES(:smi,:chismi,:index,:rank,:comp,:met,:ba,:nha, :na, :gr, :gconv, :scfconv, :ener,:chemf,:prog,:ver,:cha,:mult,:sol,:geo, :freq, :enth, :free_e, :wei)");;
query.bindValue(":smi",QVariant(SMILES));
query.bindValue(":chismi",QVariant(ChiralSMILES));
query.bindValue(":index",QVariant(IndexCS));
query.bindValue(":rank",QVariant(Confrank));
query.bindValue(":comp",QVariant(Comptype));
query.bindValue(":met",QVariant(Method));
query.bindValue(":ba",QVariant(BASE));
query.bindValue(":nha",QVariant(NheavyAtom));
query.bindValue(":na",QVariant(NAtoms));
query.bindValue(":gr",QVariant(Grid));
query.bindValue(":gconv",QVariant(GeoConvergence));
query.bindValue(":scfconv",QVariant(SCFConvergence));
query.bindValue(":ener",QVariant(Energy));
query.bindValue(":chemf",QVariant(ChemicalFormula));
query.bindValue(":prog",QVariant(SOFTWARE));
query.bindValue(":ver",QVariant(VERSION));
query.bindValue(":cha",QVariant(Charge));
query.bindValue(":mult",QVariant(Multiplicity));
query.bindValue(":sol",QVariant(SOLVANT));
query.bindValue(":geo",QVariant(Geometry));
query.bindValue(":freq",QVariant(freq));
query.bindValue(":enth",QVariant(enthalpy));
query.bindValue(":free_e",QVariant(free_enthalpy));
query.bindValue(":wei",QVariant(weight));
if (!query.exec()){
std::cout << "Une erreur s'est produite. :(" << std::endl << q2c(query.lastError().text()) << std::endl;
}
return;
Thanks for tips.

Answer 1

query.executedQuery() will return the text of the last query that was successfully executed, with placeholder values replaced with concrete values. Hopefully, it'll also work if there was an error due to bad values, etc.
Note also that the explicit QVariant constructions are never necessary. For types that are handled by QVariant, the conversion will be done automatically. For custom types, there's no QVariant constructor available and the code won't compile anyway. You'd need to use QVariant::fromValue(xyz), where xyz has a custom type that has been Q_DECL_METATYPE'd in the header where the type is declared.
Your code could be rewritten as follows:
QSqlQuery query;
query.prepare("INSERT INTO GeoAndEnergies VALUES(:smi,:chismi,:index,:rank,:comp,:met,:ba,:nha, :na, :gr, :gconv, :scfconv,"
":ener,:chemf,:prog,:ver,:cha,:mult,:sol,:geo, :freq, :enth, :free_e, :wei)");
query.bindValue(":smi", SMILES);
query.bindValue(":chismi", ChiralSMILES);
query.bindValue(":index", IndexCS);
query.bindValue(":rank", Confrank);
query.bindValue(":comp", Comptype);
query.bindValue(":met", Method);
query.bindValue(":ba", BASE);
query.bindValue(":nha", NheavyAtom);
query.bindValue(":na", NAtoms);
query.bindValue(":gr", Grid);
query.bindValue(":gconv", GeoConvergence);
query.bindValue(":scfconv", SCFConvergence);
query.bindValue(":ener", Energy);
query.bindValue(":chemf", ChemicalFormula);
query.bindValue(":prog", SOFTWARE);
query.bindValue(":ver", VERSION);
query.bindValue(":cha", Charge);
query.bindValue(":mult", Multiplicity);
query.bindValue(":sol", SOLVANT);
query.bindValue(":geo", Geometry);
query.bindValue(":freq", freq);
query.bindValue(":enth", enthalpy);
query.bindValue(":free_e", free_enthalpy);
query.bindValue(":wei", weight);
if (!query.exec()) {
qWarning() << "The query has failed:" << query.executedQuery();
}