The SQLite exception "no such table: <table> Unable to execute statement" with QSqlDatabase

[Maarouf Med Mahdi]

Hi @Stoyan that show me (), i think you saw my db i posted it ,
all tables has been created but Qt can not find it

[Maarouf Med Mahdi]

@Stoyan previously I used the encoding "system", now I've changed to UTF-8 but the same error still see

[Stoyan]

@Maarouf-Med-Mahdi
It seems that you are not connected to the database.
Try to change your code for open database.
Instead:

if(mydb.open())
        qDebug() << "connected";
    else
        qDebug() << "deconnected";

use this:

    if(!mydb.open())
    {
        qDebug() << mydb.lastError().text();
    }

BTW, what is the result from query that you use to test database connection:

select * from sqlite_master where tbl_name = 'serveurs';

[Maarouf Med Mahdi]

@Stoyan connected and that query works
select * from sqlite_master where tbl_name = 'serveurs';

[Stoyan]

@Maarouf-Med-Mahdi
OK, but what is the result? Empty set or 2-3 rows?

[Stoyan]

In SQLite a database is a single file. And I think that, if database file don't exists it is created and practically the connection is made to new empty database.
You can search on your computer for file with the name "GestionDataCenter_BD.db". I guess that there will be another such file in other folder than original database.

[Maarouf Med Mahdi]

@Stoyan i understood what you said, but i m sure i connected to the real database from a real path
mydb.setDatabaseName("D:\Applications\App Gestion Data CenterV2\GestionDataCenterV2\GestionDataCenter_BD.db");

[karlheinzreichel]

I think the answer is quite simple:
use double backslash!

instead of

 mydb.setDatabaseName("D:\Applications\App Gestion Data CenterV2\GestionDataCenterV2\GestionDataCenter_BD.db");

use

 mydb.setDatabaseName("D:\\Applications\\App Gestion Data CenterV2\\GestionDataCenterV2\\GestionDataCenter_BD.db");

regards
Karl-Heinz

[Maarouf Med Mahdi]

Hi @karlheinzreichel , i got that message
connected
invalide requette --> "file is encrypted or is not a database Unable to execute statement"

[karlheinzreichel]

@Maarouf-Med-Mahdi said in How insert data into sqlite database with Qt:

(no such table: <table> Unable to execute statement).

But before you get the error:
(no such table: <table> Unable to execute statement).

now you get
file is encrypted or is not a database Unable to execute statement

it's somehow different.

Have you tried to test the database with sqlite3 database application?

[Maarouf Med Mahdi]

@karlheinzreichel
all queries it works well with SQLiteStudio and has the same database

[Stoyan]

@Maarouf-Med-Mahdi
I'm sure there is such database in correct path. But did you found another file with the same name in other directory?
Also, you should use '/' as directory separator:

Qt uses "/" as a universal directory separator in the same way that "/" is used as a path separator in URLs. If you always use "/" as a directory separator, Qt will translate your paths to conform to the underlying operating system.

[Stoyan]

@Maarouf-Med-Mahdi
With SQLiteStudio you are connecting to real database and everything works.
With Qt you are trying to connect to wrong database and new database file is created and connected. This database is empty and that's why there is no tables in it.
Execute this query with SQLiteStudio and with Qt and compare the results.

select * from sqlite_master where tbl_name = 'serveurs';

And how much files with name "GestionDataCenter_BD.db" did you found in your computer?

[Maarouf Med Mahdi]

I copied the same database (exported) and put it in the directory of my project. and I checked with notepade that all the tables are created, in the end I gave it to QT by the way of this last database

[Maarouf Med Mahdi]

@Stoyan that query
select * from sqlite_master where tbl_name = 'serveurs';
works in the both

[Stoyan]

@Maarouf-Med-Mahdi
It always works. The question is how many rows returns in each case.

[Maarouf Med Mahdi]

@Stoyan -1
QString text_req = "select * from sqlite_master where tbl_name='serveurs'";
if(requette.exec(text_req))
qDebug()<<"requette valide"<<requette.size();
else
qDebug()<<"invalide requette"<<" --> "<<requette.lastError().text();
connected
requette valide -1

[Stoyan]

@Maarouf-Med-Mahdi
Unfortunately, SQLite doesn't support QSqlQuery::size() function.
Instead you can use this:

if(requette.exec(text_req))
{
    requette.last();
    qDebug() << requette.at() + 1;
}

[Maarouf Med Mahdi]

@Stoyan that give me -1 again

[Stoyan]

@Maarouf-Med-Mahdi
You should just change directory separator in your code from "\" to "/".
I make some tests with this code:

    QSqlDatabase mydb = QSqlDatabase::addDatabase("QSQLITE");
    mydb.setDatabaseName("C:\Projects\Test\BD.db");
    if(!mydb.open())
    {
        qDebug() << mydb.lastError().text();
    }
    qDebug() << "Tables: " << mydb.tables();
    quint16 cnt = 0;
     QSqlQuery q;
     QString text_req = "select * from sqlite_master where tbl_name='serveurs'";
     if(q.exec(text_req))
     {
         while(q.next())
         {
             cnt++;
         }
         qDebug() << "Records count: " << cnt;
     }
     else
         qDebug()<<"Invalide query"<<" --> " << q.lastError().text();

On compile it give warnings:

warning: unknown escape sequence: '\P'
warning: unknown escape sequence: '\T'
warning: unknown escape sequence: '\B'

The result was this (just like yours):

Tables:  ()
Records count:  0

When I change this row:

    mydb.setDatabaseName("C:\Projects\Test\BD.db");

with this:

    mydb.setDatabaseName("C:/Projects/Test/BD.db");

there are no warnings, everything works and the result is:

Tables:  ("serveurs", "historiques")
Records count:  2