Perhaps you should check your schema creation code. You have square brackets in all type names with embedded space and none in type names without embedded space. Maybe you would like to explain why you choose to copy type declarations verbatim from your calling programming language over to automatically generated schema definitions. SQlite only rudimentarily parses them to determine affinity. INTEGER UNSIGNED translates into INTEGER affinity, whereas UNSIGNED WORD(1) translates to NUMERIC affinity. Both may hold negative values. If you really want to limit UNSIGNED WORD to 0..65535 then you should generate an appropriate check constraint too. BTW: Your schema contains multiple fields whose names differ only by a numeric suffix. This begs the question as to why the schema is not normalized.