SQLite database: what is the right way to know if an object was initialized?

Question

Hi, I have a trouble in my database - somehow at some point it appears that a database is being closed even before it was opened.

If a database was not opened I am using the following statement: if (!database) then break;

when *database is being set to nil (database = nil) when it was not opened.

Am I doing it in a right way? Or there is some other error in my code?

Here is my code:

-(BOOL) loadDB: (NSString*) dbPath {

//Database was opened before
if (database) {
 sqlite3_close(database);
 database = nil;
}

//Opening database
if (sqlite3_open([dbPath UTF8String], &database) != SQLITE_OK)
{
 database = nil;
 return FALSE;
}

return TRUE;

}

The code is being called for multiple times and at some time it throws an exception. Why may this happen?

When I am using debugger to see where a problem occured, it shows me: sqlite3_close(database);

Thank you in advance.

Answer 1

Your close brace is too early (but I don't think that's the problem because it wouldn't compile.

As a style note, please only return ONE time from a function (and make that at the bottom). Create a BOOL, initialize it to TRUE and change it's value to FALSE when necessary.

Answer 2

Try setting the database pointer to NULL instead of nil.

-(BOOL) loadDB: (NSString*) dbPath {
    BOOL retVal = TRUE

    //Database was opened before
    if (database) {
        sqlite3_close(database);
        database = NULL; // <-- NULL not nil
    }

    //Opening database
    if (sqlite3_open([dbPath UTF8String], &database) != SQLITE_OK) {
        database = NULL; // <-- NULL not nil
        retVal = FALSE;
    }
    return retVal;
}

In Objective C nil is a nil pointer on an object. But database is a pointer to a struct, so use NULL instead.