Question

我正在开发使用本地数据库作为sqlite的应用程序。

我想为sqlite创建自定义文件我不知道该怎么做。

任何帮助都将不胜感激。

Answer 1

首先将以下文件添加到您的项目中。

https://github.com/ConnorD/simple-sqlite

然后在项目中创建database.sqlite文件。数据库包含用户第一个nam，姓氏和个人资料picutre。

将以下代码添加到AppDelegate文件中。

- (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]; 
    //    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"testing" message:@"path for database" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    //    [alert show];
    //    [alert release];

    NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"Category_DB.sqlite"];

        //NSLog(@"Default  writableDBPath: %@",writableDBPath);
    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:@"Category_DB.sqlite"];

    //NSLog(@"Default : %@",defaultDBPath);
    success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error]; 
   // NSLog(@"Success");
    if (!success) { 
        NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]); 
    } 
}

将此方法称为didFinishLaunchingWithOptions

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self createEditableCopyOfDatabaseIfNeeded];
return NO;
}

现在将以下代码写入您想要使用查询的视图控制器中。

-(void)databaseOpen
{
    NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [path objectAtIndex:0];
    NSString *myDBnew = [documentsDirectory stringByAppendingPathComponent:@"Category_DB.sqlite"];
    myDatabase = [[Sqlite alloc] init];
    [myDatabase open:myDBnew];
   // NSLog(@"database opened");

}

对于选择查询：

[self databaseOpen];    
NSString *query_fetch=[NSString stringWithFormat:@"select Max(session_id) from Report"];
NSMutableArray *userData=[[myDatabase executeQuery:query_fetch]mutableCopy];

如果您想将图像保存到数据库

-(NSString *) getImagePath{
     /* *** Modify on 16 01 2012 by Prerak   *** */

     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
     NSString *documentsDirectory = [paths objectAtIndex:0];

     NSError *error;
     [[NSFileManager defaultManager] createDirectoryAtPath:documentsDirectory withIntermediateDirectories:YES attributes:nil error:&error];

     return documentsDirectory;
}

如果您想将图像添加到数据库

arrProfilepic = [[NSMutableArray alloc]init];
    NSError *error = nil;
    NSString *stringPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0];

    NSArray *filePathsArray = [[NSFileManager defaultManager] subpathsOfDirectoryAtPath: stringPath  error:&error];

    NSLog(@"File Path Array is %@",filePathsArray);

    for(int i=0;i<[filePathsArray count];i++)
    {
        NSString *strFilePath = [filePathsArray objectAtIndex:i];
        if ([[strFilePath pathExtension] isEqualToString:@"jpg"] || [[strFilePath pathExtension] isEqualToString:@"png"] || [[strFilePath pathExtension] isEqualToString:@"PNG"])
        {
            NSString *imagePath = [[stringPath stringByAppendingString:@"/"] stringByAppendingString:strFilePath];
            NSData *data = [NSData dataWithContentsOfFile:imagePath];
            //NSLog(@"Data %@", data);
            if(data)
            {
                UIImage *image = [UIImage imageWithData:data];
                NSLog(@"Image %@", image);
                [arrProfilepic addObject:image];
            }
        }

    }
    NSLog(@"profile is %@",arrProfilepic);

对于插入查询：

 NSString *documentsDirectory = [self getImagePath];//save image to database
  NSString *imagePath;
  imagePath = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"User_%d.png",newid]];
  NSString *relativePathImage1=nil;
  NSArray *relativeArray=[imagePath componentsSeparatedByString:@"/Documents"];
  UIImage *thumbImage;
  thumbImage = [VcAddUser.portraitImageView.image imageScaledToFitSize:CGSizeMake(90, 90)];
    NSData *thumbData = UIImageJPEGRepresentation(thumbImage, 1.0f);
              [thumbData writeToFile:imagePath atomically:YES];




 NSString *query_insert=[NSString stringWithFormat:@"Insert into UserDetails(User_id,User_fname,User_lname,User_image) values(%d,'%@','Smith','%@')",newid,VcAddUser.txtFUsername.text,relativePathImage1];
 NSMutableArray *userData=[[NSMutableArray alloc]init];
 userData=[[myDatabase executeQuery:query_insert];
 [database close];

对于删除查询：

  NSString *query_user=[NSString stringWithFormat:@" delete from UserDetails where User_id=%d",Userid];
        [myDatabase executeNonQuery:query_user];
        [myDatabase close];


**For Update query:**

NSString *updatequery=[NSString stringWithFormat:@"Update UserDetails set User_fname='%@',User_lname='%@', User_image='%@' where User_id=%d",txtFUsername.text,txtLUsername.text,relativePathImage1,UseridUpdate];
    [myDatabase executeNonQuery:updatequery];
   // NSLog(@"Query user is %@",updatequery);
    [myDatabase close];

对于Web服务

-(void) CallWebservice
{
      NSMutableData  *responseData = [NSMutableData data];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
        [request setURL:[NSURL URLWithString:@"give your web service url"]];
        [request setHTTPMethod:@"POST"];
        [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
        [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
        [request setHTTPBody:[requestString dataUsingEncoding:NSUTF8StringEncoding]];
      NSURLConnection  *PostConnection = [[NSURLConnection alloc] initWithRequest:request delegate:self];
}


- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
    [responseData setLength:0];
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [responseData appendData:data];
}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
   [self removeProgressIndicator];
    UIAlertView *alt=[[UIAlertView alloc]initWithTitle:@"Internet connection is not Available!" message:@"Check your network connectivity" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alt show];

}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
   // check for response only

    /*NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];

    NSLog(@"%@",responseString);*/

    NSError *error;
    NSDictionary *results = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:&error];

    NSLog(@"%@",results);
}

如何在ios中创建sqlite自定义文件？

1 个答案: