我们如何打开一个已经存在的数据库fmdb以及在哪里包含它？

Question

我正在使用fmdb,但我不知道在哪里添加db文件.我发现这个旧的答案,我认为它不适合xcode 4.2(因为我们不再有'Resources'文件夹了).

我在'Lita'中创建了一个数据库,添加了扩展名.sqlite并添加了db文件,如下所示:

然后尝试使用以下内容

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *path = [docsPath stringByAppendingPathComponent:@"db.sqlite"];
FMDatabase *database = [FMDatabase databaseWithPath:path];
[database open];
FMResultSet *results = [database executeQuery:@"select * from tbl"];
printf("hi");
while([results next]) {
    printf("hi2");
NSString *name = [results stringForColumn:@"clm1"];
NSString *text  = [results stringForColumn:@"clm2"];        
NSLog(@"test: %@ - %@",name, text);
}
printf("done");

我正在接受'hi''完成'但从未'hi2'......

谁有人可以帮忙？

Answer 1

您希望将(已编译的)数据库作为资源添加到项目中,然后在首次启动时将其复制到应用程序的documents文件夹中.

下面是一个执行工作的示例方法,从applicationDidFinishLaunching调用它,并为所有查询使用生成的FMDatabase*.

- (FMDatabase *)openDatabase
{
    NSFileManager *fm = [NSFileManager defaultManager];
    NSString *documents_dir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *db_path = [documents_dir stringByAppendingPathComponent:[NSString stringWithFormat:@"database.s3db"]];
    NSString *template_path = [[NSBundle mainBundle] pathForResource:@"template_db" ofType:@"s3db"];

    if (![fm fileExistsAtPath:db_path])
        [fm copyItemAtPath:template_path toPath:db_path error:nil];
    FMDatabase *db = [FMDatabase databaseWithPath:db_path];
    if (![db open])
        NSLog(@"Failed to open database!");
    return db;
}