ios - How to write NSArrays and NSDictionaries for getting and to Join two table's data into another table SQLite, iPhone? -

when joining 2 tables data tableview using sqlite getting null value how write nsarray , nsdictionary.and how set objects , keys. below database class

+(nsmutablearray *)getdata {     sqlite3 *dbobj;     nsstring *dbpath  =[dbclass connectdb];     nsmutablearray *readarray=[[nsmutablearray alloc]init];     if(sqlite3_open([dbpath utf8string], &dbobj)==sqlite_ok)     {         sqlite3_stmt *statement=nil;          //**** nsstring *string=@"select name emptable";         nsstring *string=@"select emp_id, age, dept company inner join department on company.id = department.emp_id";         ;         const char *query=[string utf8string];         if(sqlite3_prepare_v2(dbobj, query, -1, &statement, null)==sqlite_ok)         {             while (sqlite3_step(statement)==sqlite_row)             {                 nsmutabledictionary *readdic=[[nsmutabledictionary alloc] init];                  [readdic setobject:[nsstring stringwithutf8string:(char *)sqlite3_column_text(statement, 2)] forkey:@"dept"];                  //[readdic setobject:[nsstring stringwithutf8string:(char *)sqlite3_column_text(statement, 1)] forkey:@"age"];                  [readarray addobject:readdic];                 // nslog(@"%@",readdic);             }         }         sqlite3_finalize(statement);     }     nslog(@"%@",readarray);     sqlite3_close(dbobj);     return readarray;  } 

the below 1 jointviewcontroller.m

- (void)viewdidload {     [super viewdidload];      array=[[nsmutablearray alloc]init];     data=[[nsmutablearray alloc]init];      array=[dbclass getdata];     for( nsdictionary *obj in array)     {         nslog(@"%@",obj);          [data addobject:[obj objectforkey:@"dept"]];         //[data addobject:[obj objectforkey:@"age"]];     }     nslog(@"\n%d",[data count]);     [table reloaddata];  } 

you need specify tablename before columnname. i.e. table particular column belongs.

see example of inner join , try relate code.

select customers.customername, orders.orderid customers inner join orders on customers.customerid=orders.customerid order customers.customername;