无法更新数据库

Question

我在更新数据库时遇到问题。我相信这是由于它可能是只读的，但我不确定。我在我的控制台中创建了我的数据库，下面的代码将数据库添加到项目文件夹，而不是在外部引用它。下面是对文件传输到项目文件夹

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 

    databaseName = @"databasenew.sql"; 


/* copy over to phone code */ 

    NSString *documentDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,   NSUserDomainMask,YES) objectAtIndex:0]; 
    NSString *sqlFile =[documentDirectory stringByAppendingPathComponent:@"databasenew.sql"]; 

if (![[NSFileManager defaultManager] fileExistsAtPath:sqlFile]) { 
    NSString *bundleSql = [[NSBundle mainBundle] pathForResource:@"databasenew" ofType:@"sql"]; 


    NSError *error = nil; 
    [[NSFileManager defaultManager] copyItemAtPath:bundleSql toPath:sqlFile error:&error]; 

    if (error) { 
     NSLog(@"Could not copy json file: %@", error); 
    } 
    else{ 
     NSLog(@"yea"); 
    } 
} 
else{ 

    NSLog(@"transfer complete"); 
} 
NSString *bundleSql = [[NSBundle mainBundle] pathForResource:@"databasenew" ofType:@"sql"]; 


databasePath = bundleSql; 


self.window.rootViewController = self.viewController; 
[self.window makeKeyAndVisible]; 
return YES; 

}

这里是我尝试更新

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *) namespaceURI qualifiedName:(NSString *)qName 
    attributes: (NSDictionary *)attributeDict 
    { 

if ([elementName isEqualToString:@"Message"]) 
{ 
    NSLog(soapResults); 
    NSString *convertString = soapResults; 
    check = [convertString intValue]; 
    NSLog(@"user is"); 
    NSLog(user); 
    if(check > 0){ 

     databaseName = @"databasenew.sql"; 
     NSString *bundleSql = [[NSBundle mainBundle] pathForResource:@"databasenew" ofType:@"sql"]; 
     databasePath = bundleSql; 

     sqlite3 *database; 

     if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) { 
      const char *sqlStatement = "UPDATE people set user = 'munch'"; 
      sqlite3_stmt *compiledStatement; 
      if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { 
       NSLog(@"success"); 
       NSLog(soapResults); 
       BOOL success = sqlite3_step(compiledStatement); 
       if (success != SQLITE_DONE) { 
        BOOL myBool=YES; 
        NSLog([NSString stringWithFormat:@"My Bool value : %d",success]); 

       } 
      }else{ 
       NSLog(@"the fail ispreparing something"); 

       NSAssert1(0, @"Error while creating update statement. '%s'", sqlite3_errmsg(database)); 
      } 


      sqlite3_finalize(compiledStatement); 

     }else{ 
      NSLog(@"fail"); 
     } 

     sqlite3_close(database); 
     NSString *string = [NSString stringWithFormat:@"%d", check]; 
     NSLog(string); 
     NSLog(@"lolololol"); 
     check = 0; 
     [self Bootup]; 

    }else{ 
      UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Problem!" message:@"Incorrect Username or Password" 
                  delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:@"Yes", nil]; 
     [alert show]; 
     [alert release]; 
    } 
    // gotoContent = checkConfirm; 
} 



if([elementName isEqualToString:@"ValidateUserResponse"]) 
{ 
    if(!soapResults) 
    { 
     soapResults = [[NSMutableString alloc] init]; 
     NSLog(soapResults); 
     NSLog(@"above is soap validate user"); 
    } 

    recordResults = TRUE; 
} 

}

我已经做了代码的代码我NDlog调试，如果更新代码成功，它会显示“成功”，但数据库本身不会更新。这是什么原因？

Answer 1

- （BOOL）someUpdateFunction BOOL updatedSuccessfully = NO;

// Open the database. 
if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) { 
    NSString *updateQuery = [[NSString alloc] initWithFormat:@"UPDATE people SET user = 'terror' WHERE user = 'greg'"]; 
    const char *query = [updateQuery UTF8String]; 
    [updateQuery release]; 

    sqlite3_stmt *statement; 
    int res = (sqlite3_prepare_v2(database, query, -1, &statement, NULL)); 

    if(res == SQLITE_OK) { 
     int result = sqlite3_step(statement); 
     if(result == SQLITE_DONE) { 
      updatedSuccessfully = YES; 
      sqlite3_finalize(statement); 
     }else { 
      NSLog(@"Failed with error code: %d", result); 
     } 
    }else { 
     NSLog(@"Failed to prepare the update query with error code: %d", res); 
    } 
}else { 
    NSLog(@"Failed to open the database"); 
} 

sqlite3_close(database); 
//NSLog(updatedSuccessfully); 
//NSLog(@"The value of the bool is %@\n", updatedSuccessfully); 
return updatedSuccessfully; 

}

我在聊天室提供这一点。谢谢小伙子们。

记得将数据库复制到其他设备上。你可以找到这段代码数据库路径：

- (NSString *) dataFilePath:(NSString *) dbName { 
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectory = [paths objectAtIndex:0]; 
NSString *dbPath = [documentsDirectory stringByAppendingPathComponent:dbName]; 
return dbPath; 

}

- （BOOL）buildtheDB { BOOL updatedSuccessfully = NO;

NSString *documentDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES) objectAtIndex:0]; 
NSString *sqlFile =[documentDirectory stringByAppendingPathComponent:kDatabaseFileName]; 

if ([[NSFileManager defaultManager] fileExistsAtPath:sqlFile] == NO) { 
    NSString *bundleSql = [[NSBundle mainBundle] pathForResource:@"database" ofType:@"sqlite"]; 

    NSError *error = nil; 

    BOOL databaseCopied = [[NSFileManager defaultManager] copyItemAtPath:bundleSql toPath:sqlFile error:&error]; 
    if (databaseCopied == NO) { 
     if (error) { 
      NSLog(@"Could not copy database file with error: %@", [error localizedDescription]); 
     } 
    }else { 
     NSLog(@"Database copied successfully"); 
    } 
} 
else{ 
    NSLog(@"Database already copied"); 
} 

return updatedSuccessfully; 

}

Answer 2

您忘却for update语句

//the binding part is missing in your code , you need to write after Prepare statement. 

sqlite3_bind_text(compiledStatement, 1, [string UTF8String], -1, SQLITE_TRANSIENT); 

if(SQLITE_DONE != sqlite3_step(compiledStatement)) 
NSAssert1(0, @"Error while updating. '%s'", sqlite3_errmsg(database)); 

sqlite3_reset(compiledStatement); 

一些代码通过this site

这将解决您的错误。