在iPhone中打开数据库时应用崩溃

Question

I am using FMDB APIS to use database in my project using the following link:https://github.com/ccgus/fmdb

in the First Step i Create and object of FMDatabase and get the DB linked:

FMDatabase *dbObject = [FMDatabase databaseWithPath:dbPath];

Now I open the Database using the following code:

 if (![dbObject open]) {
    NSLog(@"Could not Open Database");
}else {
    NSLog(@"Database Opened!");
    [dbObject executeUpdate:@"create table user(id integer primary key autoincrement, f_name text, l_name text, session_id text)"];
    [dbObject close];
}   

Now i want to write the data On Clik of button from fields. i Write the following code:

if (![dbObject open]) {
    NSLog(@"Could not Open Database");
}else {
    NSLog(@"Database Opened!");
    [dbObject executeUpdate:@"insert into user(f_name, l_name, session_id) values(?,?,?)",loginObject.fName, loginObject.lName, loginObject.sessionId,nil];
    [dbObject close];
}

Now when i reopen the DB here. in the same view controller. it gives me the following error. please note First time its opening the Database and next times its not. I dont know whats the problem. Please guide.

the Error i got is:

[NSCFString open]: unrecognized selector sent to instance 0x4e21630

Answer 1

It looks as though you're not retaining dbObject at some point. The error message says that you're sending the open message to an instance of NSString . This means that the memory that used to contain your FMDatabase object is now ocupied by a string.