问题描述
执行rc = sqlite3_open(test.db,& db)时,我得到无法打开数据库文件;
I get "unable to open database file" when executing rc = sqlite3_open("test.db", &db); ??
sqlite3 *db; // sqlite3 db struct
char *zErrMsg = 0;
int rc;
// Open the test.db file
rc = sqlite3_open("test.db", &db); // <-- creates DB if not found ??
if( rc ){
// failed
fprintf(stderr, "ERROR: Can't open database: %s\n", sqlite3_errmsg(db));
}
推荐答案
如果数据库不存在,sqlite3_open
将返回错误。要创建数据库(如果尚不存在),请使用 SQLITE_OPEN_CREATE
和将
标记(两者都是必需的): sqlite3_open_v2
SQLITE_OPEN_READWRITE
sqlite3_open
returns an error if the database does not already exist. To create the database if it doesn't already exist, use sqlite3_open_v2
with the SQLITE_OPEN_CREATE
and SQLITE_OPEN_READWRITE
flags (both are required):
rc = sqlite3_open_v2(/* DB Path */, &db, SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE, NULL);
找到 / * DB PATH * /
,您需要基于文档目录的文件名:
To find /* DB PATH */
, you need to base the filename off of the documents directory:
- (NSString *) applicationDocumentsDirectory
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
return basePath;
}
您可以使用此方便方法将文档路径与数据库名称组合:
You can use this convenience method to combine the documents path with the database name:
NSString *documents = [self applicationDocumentsDirectory];
NSString *dbPath = [documents stringByAppendingPathComponent:@"test.db"];
rc = sqlite3_open_v2([dbPath UTF8String], &db, SQLITE_OPEN_CREATE | SQLITE_OPEN_READWRITE, NULL);
这篇关于sqlite3_open:“无法打开数据库文件”的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!