C++ Qt sql lite database connection issue - c++

Question

The following code is used by me to connect to a database using Qt IDE. And if it successfully connects to the database Connected to db is printed on a label. But the issue is if I even given a wrong database path it returns Connected to db on the label how can i correct this issue?
QSqlDatabase mydb= QSqlDatabase::addDatabase("QSQLITE");
mydb.setDatabaseName("x");
if(!mydb.open()){
ui->label->setText("Failed to open the db");
}
else{
ui->label->setText("Connected to db");
}
Even though in the above code i put "x" which is not a valid database path I get "Connected to db' in the label when I run the program!
How can i correct this issue?

Answer 1

Qt uses as SQLite backend uses the sqlite library, so you will use one of the functions to open the database:
int sqlite3_open(
const char *filename, /* Database filename (UTF-8) */
sqlite3 **ppDb /* OUT: SQLite db handle */
);
int sqlite3_open16(
const void *filename, /* Database filename (UTF-16) */
sqlite3 **ppDb /* OUT: SQLite db handle */
);
int sqlite3_open_v2(
const char *filename, /* Database filename (UTF-8) */
sqlite3 **ppDb, /* OUT: SQLite db handle */
int flags, /* Flags */
const char *zVfs /* Name of VFS module to use */
);
According to the docs:
These routines open an SQLite database file as specified by the
filename argument. The filename argument is interpreted as UTF-8 for
sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
order for sqlite3_open16(). A database connection handle is usually
returned in *ppDb, even if an error occurs. The only exception is that
if SQLite is unable to allocate memory to hold the sqlite3 object, a
NULL will be written into *ppDb instead of a pointer to the sqlite3
object. If the database is opened (and/or created) successfully, then
SQLITE_OK is returned. Otherwise an error code is returned. The
sqlite3_errmsg() or sqlite3_errmsg16() routines can be used to obtain
an English language description of the error following a failure of
any of the sqlite3_open() routines.
From which we conclude that if the database does not exist this will create it, it will only generate the error in creating it if there are problems to allocate memory.