Ios 从sqlite表中删除原始数据时出现的问题

这就是我在头球中所做的

static sqlite3 *database = nil;
static sqlite3_stmt *deleteStmt = nil;

@implementation SQLAppDelegate

@synthesize window;
@synthesize navigationController;
@synthesize coffeeArray;

这就是我用来删除原始数据的方法

    - (void) removeCoffee:(NSNumber *)coffeeObj {

      NSLog(@"coffeeObj%@",coffeeObj);

        int myInteger = [coffeeObj integerValue];
        NSLog(@"myInteger%d",myInteger);
      // print this myInteger0


        NSLog(@"%@",coffeeArray);
       //print object
   if (sqlite3_open([self getDBPath], &database) == SQLITE_OK)
   {    
   NSLog(@"myInteger%@",[self getDBPath]);

        NSString *sql = [NSString stringWithFormat: @"delete from Coffee where CoffeeID =%d",myInteger];

                             const char *del_stmt = [sql UTF8String];
       NSLog(@"%@",del_stmt); // getting print 
 // print this  delete from Coffee where CoffeeID =0.

                             sqlite3_prepare_v2(database, del_stmt, -1, & deleteStmt, NULL);
                 NSLog(@"sqlite3_step(deleteStmt) ==           SQLITE_DONE%@",sqlite3_step(deleteStmt) == SQLITE_DONE);

    // this print null

                             if (sqlite3_step(deleteStmt) == SQLITE_DONE)
                             { 
                               //NSLog(@"hi") this is not getting print

                             } else {
                                  //NSLog(@"hi") this is getting print
                             }
                             sqlite3_finalize(deleteStmt);
                             sqlite3_close(database);
    [coffeeArray removeObjectAtIndex:myInteger];
        NSLog(@"%@",coffeeArray);
       // object is deleted 
    }
}

我的桌子如下

table name = Coffee

CoffeeID(INTEGER)=0

CoffeeName(VARCHAR)=Latte

Price(REAL)=2.99

---

若对象从数组中删除，那个么它就不会出现在表格单元格中。但它没有从数据库表中删除，这就是为什么当我再次启动应用程序时，它会再次显示。请帮助我做错事。

开始删除对象之前，请确认数据库是否正确打开。就这样试试吧

//Setting path 
    NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

      NSString *docsDir = [dirPaths objectAtIndex:0];

    databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"database.db"]];

    const char *dbpath=[databasePath UTF8String];

        if (sqlite3_open(dbpath, &database) == SQLITE_OK)
        {
      NSString *sql = [NSString stringWithFormat: @"delete from Coffee where CoffeeID =%d",myInteger];

                             const char *del_stmt = [sql UTF8String];

                             sqlite3_prepare_v2(database, del_stmt, -1, & deleteStmt, NULL);
                             if (sqlite3_step(deleteStmt) == SQLITE_DONE)
                             {

                             } else {

                             }
                             sqlite3_finalize(deleteStmt);
                             sqlite3_close(database);
    [coffeeArray removeObjectAtIndex:myInteger];
        NSLog(@"%@",coffeeArray);
       // object is deleted 

        }

---

将nslog置于if和else条件下，比较SQLITE_DONE并检查它所说的话！如果条件从它跳转到sqlite3_finalize（deleteStmt），则它不会进入；sqlite3_关闭（数据库）；检查@Ganapathy的答案它应该只是连接问题。Ganapathy我根据你说的编辑了我的问题，请再次检查它，如果（sqlite3_open（dbpath，&database）==SQLITE_OK）语句如你所说是正确的。你检查过了吗？dbpath应该是唯一的path或path/SQL.sqlite？是的，当我打印了东西时，它会以这种方式打印检查你更新的答案是否正确？我犯了一些错误。

if(sqlite3_open([[self filepath] UTF8String], &db) == SQLITE_OK)
    {
        Deletestatement = nil;  

        if(Deletestatement == nil)
        {
            const char *sql = "delete from Sqlitemanager2;";

            if(sqlite3_prepare_v2(db, sql, -1, &Deletestatement, NULL) != SQLITE_OK)
                NSAssert1(0, @"Error while creating delete statement. '%s'", sqlite3_errmsg(db));
        }

        if (SQLITE_DONE != sqlite3_step(Deletestatement)) //prathibha for problem in if
            NSAssert1(0, @"Error while deleting. '%s'", sqlite3_errmsg(db));

        sqlite3_finalize(Deletestatement);

    }
I hope this will help you.