Question

In my application, I have multiple images in an SQLite database since I want to change to the next image on button click.

Here is my code:

 -(void)Readthesqlitefile:(NSInteger *)sno
 {
sqlite3 *database;//database object
NSString *docpath=[self doccumentspath];//get sqlite path
const char *ch=[docpath UTF8String];//string to constant char UTF8string  main part to connect DB

if (sqlite3_open(ch, &database)==SQLITE_OK) {

    const char *chstmt="SELECT * FROM animal where rowid=  = %d",sno;

    sqlite3_stmt *sqlstmt;//to execute the above statement
    if (sqlite3_prepare_v2(database, chstmt, -1, &sqlstmt, NULL)==SQLITE_OK)
    {
        while (sqlite3_step(sqlstmt)==SQLITE_ROW)
        {
            const char *Bname=(char *)sqlite3_column_text(sqlstmt, 0);
            //converting const char to nsstring
            NSString *Bndname=[NSString stringWithFormat:@"%s",Bname];
            NSLog(@"Brand Names=%@",Bndname);
            lb1.text=[NSString stringWithFormat:Bndname];   

            NSUInteger legnt=sqlite3_column_bytes(sqlstmt, 1);

            if (legnt>0) {

                NSData *dt=[NSData dataWithBytes:sqlite3_column_blob(sqlstmt, 1) length:legnt];
                clsimg=[UIImage imageWithData:dt];//converting data to image
                imager.image=clsimg;
            }
            else {
                clsimg=nil;
            }
     }
    }
    sqlite3_finalize(sqlstmt);
}
sqlite3_close(database);
}

Button click function:

  -(IBAction)changenext
  {
  int j;
  for (j=1; j<10; j++)
  {
      [self Readthesqlitefile:j];
  }

  }

It’s not working. Please help me to solve it.

Answer 1

From your question I understand that you need to change the image on each button click. If I’m correct then change the changenext method like:

-(IBAction)changenext
  {
    static int j = 0;
    if (j > 10)
    {
       j = 0;
    }
    [self Readthesqlitefile:j];
    j++;
  }

The above method will change the image on each button click. After displaying the last image it again starts from first image.

EDIT:

Also this line seems to be wrong

const char *chstmt="SELECT * FROM animal where rowid= = %d",sno; .

There is no == operator in sqlite3 (I’m think so).
Replace that line by,

NSString *query    = [NSString stringWithFormat:@"SELECT * FROM animal where rowid = %d",sno];
const char *chstmt = [query UTF8String];