FMDB query with char

Question

I'm currently trying to execute a query on a database of words. The database is organized such that I can access by first letter of the word, and by length of the word. However, I'm having trouble when I search using a letter and length:

//random letter sends an NSString with just a single letter from the English alphabet
NSString * randomLetter = [self randomLetter];
int characterCodeInASCII = [randomLetter characterAtIndex:0];

FMResultSet *rs = [db executeQuery:@"SELECT * FROM WORDS WHERE INDEXER=? AND LENGTH=?",characterCodeInASCII,length];

Unfortunately, the query isn't returning any values. I've tried this using a char as the input, as a string, and as an int.

I'm quite confused since I can do the same query using ruby:

list=db1.execute("SELECT * FROM WORDS WHERE INDEXER=110 AND LENGTH=7")

And get 453 results....

The sqlite table has the following columns:

>> db1.execute("SELECT * FROM sqlite_master")
=> [["table", "words", "words", 2, "CREATE TABLE words(word VARCHAR(15) PRIMARY KEY, indexer VARCHAR(1), length INTEGER)"], ["index", "sqlite_autoindex_words_1", "words", 3, nil]]

Any ideas on what I might be missing?

Thanks much!

Answer 1

FMDB is expecting all of the arguments to the executeQuery: method to be objects, and an int isn't an object.

There are a couple of approaches you could take:

1. Box the int in an NSNumber. That would look like this:

   NSString *randomLetter = ...;
   NSNumber *characterCode = [NSNumber numberWithInt:[randomLetter characterAtIndex:0]];
   
   NSNumber *length = [NSNumber numberWithInt:lengthAsInt];
   FMResultSet *rs = [db executeQuery:@"SELECT * FROM WORDS WHERE INDEXER=? AND LENGTH=?", characterCode, length];
   

2. Use a different method, such as the executeQueryWithFormat: method:

   FMResultSet *rs = [db executeQueryWithFormat:@"SELECT * FROM WORDS WHERE INDEXER = %d AND LENGTH + %d", characterCodeInASCII, length];