sqlite3_prepare_v2（）== SQLITE_OK返回NO並且沒有找到現有表

Question

我正在開發一個使用sqlite3數據庫文件的iphone應用程序。我使用下面的代碼從sqlite3數據庫中選擇;

NSString* dbYolu = [NSString stringWithFormat:@"%@/emhdb3.sqlite3",NSHomeDirectory()]; 

sqlite3* db; 

NSLog(@"%@ dbyolu : ", dbYolu); 

if (sqlite3_open([dbYolu UTF8String], &db) == SQLITE_OK) 
{ 
    NSString *query = [NSString stringWithFormat: @"SELECT username, mobile FROM peopleto WHERE namesurname=\"%@\"", name.text]; 
    NSLog(@"%@ : query", query); 
    sqlite3_stmt *stmt; 

    if (sqlite3_prepare_v2(db, [query UTF8String], -1, &stmt, nil) == SQLITE_OK) // statement stmt returns null and returns SQLITE_OK = FALSE. 
    { 
     NSLog(@"stepped in SQLITE_OK is TRUE"); 
     while (sqlite3_step(stmt) == SQLITE_ROW) 
     { 
      NSString* ders_kodu = [NSString stringWithUTF8String:(char*)sqlite3_column_text(stmt, 0)]; 
      double not = sqlite3_column_double(stmt, 1); 

      NSLog(@"%@ : %f", ders_kodu, not); 
     } 
    } 
    else 
    { 
     NSLog(@"%@ - but failed", stmt); 
    } 
    sqlite3_finalize(stmt); 
} 
else 
    NSLog(@"db could not be opened"); 

它未能在 「sqlite3_prepare_v2（分貝，[查詢UTF8字符串]，-1，&語句，無）== SQLITE_OK」 上方點。並且錯誤是：「錯誤：沒有這樣的表：peopleto。但它成功返回表格的內容，當我在sql瀏覽器中運行此查詢時，我的意思是這個查詢是正確的並且正在工作。

btw，與上viewLoad

- (void)viewDidLoad 
{ 
NSString *docsDir; 
NSArray *dirPaths; 

// Get the documents directory 
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 

docsDir = [dirPaths objectAtIndex:0]; 

// Build the path to the database file 
databasePath = [[NSString alloc] initWithString:[docsDir stringByAppendingPathComponent: @"emhdb3.sqlite3"]]; 

NSLog(@"dbpath : %@", databasePath); 
NSFileManager *filemgr = [NSFileManager defaultManager]; 

if ([filemgr fileExistsAtPath: databasePath ] == NO) 
{ 
    const char *dbpath = [databasePath UTF8String]; 
    NSLog(@"db not found"); 
    if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK) 
    { 
     NSLog(@"SQLITE_OK is passed"); 
     //.... some codes here, doesn't metter for me because SQLITE_OK = true 
    } else { 
     status.text = @"Failed to open/create database"; 
    } 
} 
else if ([filemgr fileExistsAtPath:databasePath] == YES) 
{ 
    NSLog(@"i found the file here : %s",[databasePath UTF8String]); 
} 
NSLog(@"completed"); 
[super viewDidLoad]; 
} 

下面的代碼路徑我有數據庫文件在我的項目文件夾，並添加到項目中。 我缺少什麼？

感謝

///// //

我很抱歉更新我的問題，但stackoverflow不允許我添加新的，

請在下面找到我的更新;

這裏是更新的版本的代碼：

viewLoad part;

- (void)viewDidLoad 
{ 
[self createEditableCopyOfDatabaseIfNeeded]; 

NSString *docsDir; 
NSArray *dirPaths; 
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
docsDir = [dirPaths objectAtIndex:0]; 
databasePath = [[NSString alloc] initWithString:[docsDir stringByAppendingPathComponent:@"emhdb3.sqlite3"]]; 

NSLog(@"dbpath : %@", databasePath); 
NSFileManager *filemgr = [NSFileManager defaultManager]; 

if ([filemgr fileExistsAtPath: databasePath ] == NO) 
{ 
const char *dbpath = [databasePath UTF8String]; 
    if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK) 
    { 
     char *errMsg; 
     const char *sql_stmt = "CREATE TABLE IF NOT EXISTS peopleto (pId INTEGER PRIMARY KEY AUTOINCREMENT, namesurname TEXT, mobile TEXT)"; 
     if (sqlite3_exec(contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK) 
     { 
      status.text = @"Failed to create table"; 
     } 
     sqlite3_close(contactDB); 
    } else { 
     status.text = @"Failed to open/create database"; 
    } 
} 
else if ([filemgr fileExistsAtPath:databasePath] == YES) 
{ 
    NSLog(@"%s is filepath",[databasePath UTF8String]); 
} 
NSLog(@"checkpoint 4"); 
[super viewDidLoad]; 
} 

buraya巴斯卡birşeyYAZ

- (void)createEditableCopyOfDatabaseIfNeeded { 
NSLog(@"entered createEditableCopyOfDatabaseIfNeeded"); 
BOOL success; 
NSFileManager *fileManager = [NSFileManager defaultManager]; 
NSError *error; 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"emhdb3.sqlite3"]; 
success = [fileManager fileExistsAtPath:writableDBPath]; 
if (success) 
{ 
    NSLog(@"success == YES returned"); 
    return; 
} 
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"emhdb3.sqlite3"]; 
success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error]; 
if (!success) { 
    NSLog(@"Failed to create writable database file with message '%@'.", [error localizedDescription]); 
} 
else{ 
    NSLog(@"checkpoint 2"); 
} 
} 

和所執行的選擇查詢的一部分;

-(IBAction)findcontact2:(id)sender 
{ 
NSString *dbYolu = databasePath; 
sqlite3* db; 

NSLog(@"%@ dbyolu : ", dbYolu); 

if (sqlite3_open([dbYolu UTF8String], &db) == SQLITE_OK) 
{ 
    NSString *query = [NSString stringWithFormat: @"SELECT namesurname, mobile FROM peopleto"]; //any query 

    NSLog(@"%@ : query", query); 

    sqlite3_stmt *stmt; 

    if (sqlite3_prepare_v2(db, [query UTF8String], -1, &stmt, nil) == SQLITE_OK) 
    { 
     NSLog(@"SQLITE is OK"); 
     while (sqlite3_step(stmt) == SQLITE_ROW) 
     { 
      NSString* ders_kodu = [NSString stringWithUTF8String:(char*)sqlite3_column_text(stmt, 0)]; 
      double not = sqlite3_column_double(stmt, 1); 

      NSLog(@"%@ : %f", namesurname, mobile); 
     } 
    } 
    else 
    { 
     NSLog(@"Error=%s",sqlite3_errmsg(db)); // error message : Error=no such table: peopleto 
     NSLog(@"%@ - is stmt", stmt); //stmt is null 
    } 
    sqlite3_finalize(stmt); 
} 
else 
    NSLog(@"could not open the db"); 
} 

正如我上面所指出的，錯誤是錯誤=沒有這樣的表：peopleto和語句則返回null

Answer 1

請檢查DB這是你的主包中包含的表，然後嘗試將它複製到資源文件夾和您的快速回復crazycreator上述

Answer 2

你複製你的SQL文件到文件，如果不是你需要做的第一。在將SQL文件添加到項目中時，它會添加到您的包中，而不是添加到文檔目錄中。你需要複製，首先

- (void)createEditableCopyOfDatabaseIfNeeded { 
    // First, test for existence. 
    BOOL success; 
    NSFileManager *fileManager = [NSFileManager defaultManager]; 
    NSError *error; 
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDirectory = [paths objectAtIndex:0]; 
    NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"bookdb.sql"]; 
    success = [fileManager fileExistsAtPath:writableDBPath]; 
    if (success) 
     return; 
    // The writable database does not exist, so copy the default to the appropriate location. 
    NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"bookdb.sql"]; 
    success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error]; 
    if (!success) { 
     NSLog(@"Failed to create writable database file with message '%@'.", [error localizedDescription]); 
    } 
}