What is problem with qQuery.lastInsertId().toInt() ? why below function return -1 for u32FileId variable ?

Qt embedded developer

QSqlError FileLog::InsertData(UINT32 &u32FileId)
{
FUNCTION_IN;
QSqlQuery qQuery;

qQuery.prepare("INSERT INTO "+sDBTableName[DBTABLE_FILELOG]+"\
                 (FilePath,\
                  FileType,\
                  FileTagName,\
                  Comment,\
                  InsertedDate,\
                  IsDirty)"
                        "VALUES (?, ?, ?, ?, ?, ?)");
qQuery.addBindValue(sFilePath);
qQuery.addBindValue(u8FileType);
qQuery.addBindValue(sFileTagName);
qQuery.addBindValue(sComment);
qQuery.addBindValue(dCurrentDate);
qQuery.addBindValue(u8Dirty);

if(!pMainApp.ObjDbOperations.ExecuteQuery(qQuery))
    return qQuery.lastError();

u32FileId = qQuery.lastInsertId().toInt();  //Get Last Auto Increment ID
FUNCTION_OUT;
return QSqlError();

}

jsulm

@Qt-embedded-developer According to https://doc.qt.io/qt-5/qsqlquery.html#lastInsertId not every database supports returning last insert id. You should check whether yours does using https://doc.qt.io/qt-5/qsqldriver.html#hasFeature

Qt embedded developer

@Qt-embedded-developer

so what i need to do to get the last auto increment id of data base in my case

jsulm

@Qt-embedded-developer Did you check whether your database supports this using https://doc.qt.io/qt-5/qsqldriver.html#hasFeature as I suggested?

Qt embedded developer

@jsulm yes it gives positive values but some time why -1 it return. actually it need to return 0 or positive last id

jsulm

@Qt-embedded-developer If it returns -1 is the new row actually inserted?

Qt embedded developer

@jsulm no new row not inserted but realtional data base table contains new row which has -1 value due to u32FileId

jsulm

@Qt-embedded-developer said in What is problem with qQuery.lastInsertId().toInt() ? why below function return -1 for u32FileId variable ?:

no new row not inserted but realtional data base table contains new row which has -1

Sorry, I don't understand this.
If you execute the INSERT query - is there new row in your table afterwards or not?

"//Get Last Auto Increment ID" - do you have an autoincrement id column in that table?

Qt embedded developer

@jsulm

Qt embedded developer about 3 hours ago

QSqlError FileLog::InsertData(UINT32 &u32FileId)
{
FUNCTION_IN;
QSqlQuery qQuery;

qQuery.prepare("INSERT INTO "+sDBTableName[DBTABLE_FILELOG]+"
(FilePath,
FileType,
FileTagName,
Comment,
InsertedDate,
IsDirty)"
"VALUES (?, ?, ?, ?, ?, ?)");
qQuery.addBindValue(sFilePath);
qQuery.addBindValue(u8FileType);
qQuery.addBindValue(sFileTagName);
qQuery.addBindValue(sComment);
qQuery.addBindValue(dCurrentDate);
qQuery.addBindValue(u8Dirty);

if(!pMainApp.ObjDbOperations.ExecuteQuery(qQuery))
return qQuery.lastError();

u32FileId = qQuery.lastInsertId().toInt(); //Get Last Auto Increment ID
FUNCTION_OUT;
return QSqlError();

}

above function is called by below function
void Camera::MakeFileEntry(QString sFilePath, CAPTURED_FILETYPE eFileType)
{
FileLog *ObjFileLog = NULL;
ObjFileLog = new FileLog();
if(IS_VALID_OBJ(ObjFileLog))
{
ObjFileLog->sFilePath = sFilePath;
ObjFileLog->u8FileType = eFileType;
ObjFileLog->dCurrentDate = QDate::currentDate();
ObjFileLog->u8Dirty = DIRTYBIT_SET;

    ObjFileLog->InsertData(u32CamFileId);
    DELETE_OBJ(ObjFileLog);
}

}

now we have used this u32CamFileId to insert in readinglog table

ObjReadingLog->u32FileId = u32CamFileId;

why above code return -1 for u32CamFileId ?

jsulm

@Qt-embedded-developer said in What is problem with qQuery.lastInsertId().toInt() ? why below function return -1 for u32FileId variable ?:

why above code return -1 for u32CamFileId ?

If you do not answer my questions I cannot help you...

Qt embedded developer

@jsulm

no new row inserted in file log

yes we get auto increment id where -1 not returned

why above code return -1 for u32CamFileId ? this questions answer i not get it. why it comes i want to know

jsulm

@Qt-embedded-developer said in What is problem with qQuery.lastInsertId().toInt() ? why below function return -1 for u32FileId variable ?:

why above code return -1 for u32CamFileId ?

I guess because nothing was inserted?
"no new row inserted in file log"

Qt embedded developer

@jsulm thank you