sqlite get single row - sqlite

Question

NSString *cityInput = cityField.text;
NSString *code = #"";
NSString *query = #"SELECT code FROM country WHERE cityname = UPPER(?)";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(database, [query UTF8String],-1, &statement, nil) == SQLITE_OK)
{
sqlite3_bind_text(statement, 1, [cityInput UTF8String], -1, SQLITE_STATIC);
while(sqlite3_step(statement) == SQLITE_ROW) {
code = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 0)];
}
}
if(sqlite3_step(statement) != SQLITE_DONE){
NSLog(#"DB: query KO");
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"ALERT" message:#"City not found" delegate:nil cancelButtonTitle:nil otherButtonTitles:#"OK", nil];
[alertView show];
return;
}
sqlite3_close(database);
Two questions:
1) for get single row i must use while loop?
2) if there isn't result in the query how alert "city not found"

Answer 1

Obviously you will get the last row,,
code
should be an array u might declare it like this
NSMutableArray *code=[NSMutableArray array];
then in the while loop use
[code addobject:[NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 0)]];
I hope this is clear enough:)

Answer 2

Using while gives you the last row and it is not needed. Add limit 1 clause to your query, or simply take the first row returned;
Decide whether to show alert by checking return code.

Answer 3

Maybe two answers,
1) No, just an if clause will do
2) Do an assignement and then run an if clause on it
int result = sqlite3_step(statement)
if (result == SQLITE_ROW){
//processline
}
else{
//show alert
}