Question

When I’m trying to fetch data from the sqlite database table the NSArray has a capacity of 100 and the count array has a capacity of 9. count[5] returns to me rubbish data which is not in the table at all. Even the first 5 records returned correctly.

    if(sqlite3_open([dbPath UTF8String],&database)==SQLITE_OK){

        const char* sql2= " select * from Bcars";

        sqlite3_stmt *selectstatment;

        if(sqlite3_prepare_v2(database,sql2,-1,&selectstatment,Nil)==SQLITE_OK){

            while(sqlite3_step(selectstatment)==SQLITE_ROW){
                // fetch the id


                 count[i++]=sqlite3_column_int(selectstatment, 0);

                 carobject.primarykey=sqlite3_column_int(selectstatment, 0);


                [ar addObject:[NSString stringWithUTF8String:(char*)sqlite3_column_text(selectstatment, 1)]];
                [ar1 addObject:[NSString stringWithUTF8String:(char*)sqlite3_column_text(selectstatment, 2)]];


            } 
        }

    }
    else 
    {

    sqlite3_close(database);
        self.statustext.text=@" database closed";
    }

self.statustext.text=[[NSString alloc]initWithFormat:@"%d",count[4]];/* when I try to return count[5] it gives me rabbish value !!*/

    self.searchtext.text=(NSString*)[ar objectAtIndex:5];//here is an error occurred !!

Answer 1

There are a couple of issues with your code:

• You have not initialized the i counter so I presume that it has been initialized outside the snippet, or?
• How do you know how much data is actually available in the database? The count array has to be large enough to hold all the rows or you will overwrite some unallocated memory. Maybe you know this beforehand or else you should find out e.g. by executing some SQL statement aka "SELECT COUNT(*) FROM Bcars".
• Are you absolutely sure that the database holds more than 5 entries? The code just assumes this, but doesn’t make any checks on the value of i or [ar count] whether you actually received these entries?
• Make sure you clean up after execution by calling sqlite3_finalize()