objective c - how can i alter table in sqlite database through the obj c methods in iphone project -

hii every one

i need add 1 column existing table how can alter table in sqlite database through obj c ,i using following code inserting data table in same way how can write updata table method

- (void) insertrecord {   if(addstmt == nil) {     const char *sql = "insert tbl_users(firstname,middlename) values(?,?)";     if(sqlite3_prepare_v2(database, sql, -1, &addstmt, null) != sqlite_ok)         nsassert1(0, @"error while creating add statement. '%s'", sqlite3_errmsg(database)); }  sqlite3_bind_text(addstmt, 1, [strfirstname utf8string], -1, sqlite_transient); sqlite3_bind_text(addstmt, 2, [strmiddlename utf8string], -1, sqlite_transient); //sqlite3_bind_text(addstmt, 3, [strlogin utf8string], -3, sqlite_transient);   if(sqlite_done != sqlite3_step(addstmt))     nsassert1(0, @"error while inserting data. '%s'", sqlite3_errmsg(database)); else     //sqlite provides method last primary key inserted using sqlite3_last_insert_rowid     //productid = sqlite3_last_insert_rowid(database);  //reset add statement. sqlite3_reset(addstmt); 

}

can 1 me,,thanx in advance

this might of use. header file

nsstring *databasepath; 

.m file //make call these methods

    [self checkandcreatedb ];     [self alterdb];  -(void)checkandcreatedb {     nsstring* databasename = @"masterdb.sqlite";     nsarray *documentpaths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);     nsstring *documentsdir = [documentpaths objectatindex:0];     databasepath = [documentsdir stringbyappendingpathcomponent:databasename];     bool success1;     nsfilemanager *filemanager = [nsfilemanager defaultmanager];     success1 = [filemanager fileexistsatpath:databasepath];     if(success1) return;     nsstring *databasepathfromapp = [[[nsbundle mainbundle] resourcepath] stringbyappendingpathcomponent:databasename];     [filemanager copyitematpath:databasepathfromapp topath:databasepath error:nil]; }  -(void) alterdb{     sqlite3 *database;     sqlite3_stmt *statement;      if(sqlite3_open([databasepath utf8string], &database) == sqlite_ok)     {          nsstring *updatesql = [nsstring stringwithformat: @"alter table user add column testcolumn text"];         const char *update_stmt = [updatesql utf8string];         sqlite3_prepare_v2(database, update_stmt, -1, &statement, null);          if(sqlite3_step(statement)==sqlite_done)          {             uialertview *alert = [[uialertview alloc] initwithtitle:@"db altered" message:@"success" delegate:self cancelbuttontitle:@"ok" otherbuttontitles:nil];                 [alert show];             [alert release];             alert=nil;          }         else          {             uialertview *alert = [[uialertview alloc] initwithtitle:@"db updation" message:@"db not altered" delegate:self cancelbuttontitle:@"ok" otherbuttontitles:nil];                [alert show];             [alert release];             alert=nil;         }            // release compiled statement memory         sqlite3_finalize(statement);             sqlite3_close(database);     } }