ios - ios fmdb 从文件加载数据库

Question

我使用 sqlite 和 fmdb 包装器。我的加载数据库代码是这样的：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsPath = [paths objectAtIndex:0];
NSString *path = [docsPath stringByAppendingPathComponent:@"biscuit.sqlite"];
FMDatabase *db = [FMDatabase databaseWithPath:path]; 

我添加biscuit.sqlite到我的项目中，但此代码创建新文件而不是打开现有文件。我怎样才能加载这个文件？

Answer 1

如果您只想从数据库中读取数据，请尝试使用以下代码：

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

如果您需要读/写访问权限，则必须先将数据库复制到可写用户文件夹。

NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
NSString *dbPath = [documentsDir stringByAppendingPathComponent:@"biscuit.sqlite"];
BOOL success = [fileManager fileExistsAtPath:dbPath];
if (!success) {

    NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"biscuit.sqlite"];
    success = [fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:&error];

    if (!success) {
        NSLog(@"Failed to create writable DB. Error '%@'.", [error localizedDescription]);
    } else {
        NSLog(@"DB copied.");
    }
}else {
    NSLog(@"DB exists, no need to copy.");
}