How should I specify the path for an sqlite db in

问题:

After adding it as a resource, the database file itself is in the project root.

I've only been able to open it by specifying the full path as OS X sees it, i.e., "/Users/Louis/Documents/Test Project/test.db".

But of course there is no such path on an iPhone.

I think I should define the path as "application root/test.db" but I don't know how, or if that would even work anywhere else besides my development machine.

Thanks for any ideas.

回答1:

To get the path of the file you've added in XCode you would use pathForResource:ofType: with your mainBundle.

NSString *path = [[NSBundle mainBundle] pathForResource:@"yourDb" ofType:@"sqlite"];

But you can't change files in the mainBundle. So you have to copy it to another location. For example to the library of your app.

You could do it like this:

NSString *libraryPath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, YES) lastObject];
NSString *targetPath = [libraryPath stringByAppendingPathComponent:@"yourDB.sqlite"];

if (![[NSFileManager defaultManager] fileExistsAtPath:targetPath]) {
    // database doesn't exist in your library path... copy it from the bundle
    NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"yourDb" ofType:@"sqlite"];
    NSError *error = nil;

    if (![[NSFileManager defaultManager] copyItemAtPath:sourcePath toPath:targetPath error:&error]) {
        NSLog(@"Error: %@", error);
    }
}

回答2:

Don't just use the SQLite API, use this amazing wrapper called FMDB: https://github.com/ccgus/fmdb

回答3:

Getting Paths to Standard Application Directories