当我在iOS上尝试使用SQLite时，INSERT和UPDATE无法正常工作 [英] When I try SQLite on iOS, INSERT and UPDATE does not work

问题描述

我在user.db中创建了一个表，该文件位于我的xcode项目文件夹中.

I createed a table in user.db, this file is in my xcode project folder.

create table user (uid INTEGER PRIMARY KEY ASC AUTOINCREMENT, username, mobile);

接下来，在应用程序委托.m文件中，插入两行，然后查询select * from user并将其打印.

Next, in the app delegate .m file, I insert two rows, then I query select * from user and print it.

但是，使用语句和sqlite3_exec，插入不会成功，并且完全没有错误. user.db具有我从sqlite命令行插入的3行.当我运行该应用程序时，它会打印5行数据，我会插入2行，但是当我在sqlite命令行中查询时，仍然有3行，是否没有提交两个新行?

However, use statement and sqlite3_exec, the insertions are not successful, and there are no errors at all. user.db has 3 rows I inserted from sqlite command line. When I run this app, it prints 5 rows of data, 2 rows are inserted by me, but when I query in sqlite command line, there are still 3 rows, the two newer rows are not committed?

我还运行sqlite3_get_autocommit，并找到了autocommit=1，那么我错过了什么导致这种情况发生?

I also run sqlite3_get_autocommit, and find out autocommit=1, so what have I missed to cause this to happen?

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  // Override point for customization after application launch.
  [self.window makeKeyAndVisible];

  NSString* file = [[NSBundle mainBundle] pathForResource:@"user" ofType:@"db"];
  sqlite3* database = NULL;
  if(sqlite3_open([file UTF8String], &database) == SQLITE_OK)
  {
    NSLog(@"database open successfully.");
    // stmt

    // int autocommit = sqlite3_get_autocommit(database);

    sqlite3_stmt* stmt;
    static char * sql = "insert into user (username, mobile) values('xxxx', '5555555');commit;";
    int success = sqlite3_prepare_v2(database, sql, -1, &stmt, NULL);
    if(success != SQLITE_OK)
    {
      NSLog(@"create stmt failed");
    }
    success = sqlite3_step(stmt);
    if(success != SQLITE_OK)
    {
      NSLog(@"insert failed");
    }
    sqlite3_finalize(stmt);

    sqlite3_exec(database, "begin;insert into user (username, mobile) values('yyyy', '666666');commit;", NULL, NULL, 0);

    // insert 
    char *zErrMsg = 0;
    int rc = sqlite3_exec(database, "select * from user", MyCallback, 0, &zErrMsg);
    if(rc != SQLITE_OK)
    {
      fprintf(stderr, "SQL error: %s\n", zErrMsg);
    }
  }
  sqlite3_close(database);
  return YES;
}

推荐答案

您无法更新存储在应用程序资源中的数据库.尝试将数据库复制到应用程序的Document或Library文件夹中，然后在那里更新数据库.

You can't update databases stored in the app resources. Try copying the database to your app's Document or Library folder and then updating the database there.

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