sqlite-objc.m

- (BOOL)executeQuery:(NSString *)query
	parameters:(NSArray<__kindof NSObject *> *)params
	block:(BOOL(^)(NSArray<NSString *> *, NSArray *))block
{
	sqlite3_stmt *stmt = NULL;
	int status = sqlite3_prepare_v2(_databaseHandle, query.UTF8String, -1, &stmt, NULL);
	if (status != SQLITE_OK) {
		if (stmt) sqlite3_finalize(stmt);
		return NO;
	}
	int i=1;
	for (__kindof NSObject *object in params) {
		if ([object isKindOfClass:[NSString class]]) {
			sqlite3_bind_text(stmt, i++, [(NSString *)object UTF8String], -1, SQLITE_TRANSIENT);
		}
		else if ([object isKindOfClass:[NSNumber class]]) {
			sqlite3_bind_int(stmt, i++, [(NSNumber *)object intValue]);
		}
		else if ([object isKindOfClass:[NSNull class]]) {
			sqlite3_bind_null(stmt, i++);
		}
		else {
			[NSException
				raise:NSInvalidArgumentException
				format:@"An unsupported object was passed to -[%@ %@]: %@",
				NSStringFromClass(self.class),
				NSStringFromSelector(_cmd),
				object
			];
		}
	}
	__kindof NSArray *columns = [NSMutableArray new];
	NSMutableArray *row = [NSMutableArray new];
	if (block) {
		while ((status = sqlite3_step(stmt)) == SQLITE_ROW) {
			for (i=0; i<sqlite3_column_count(stmt); i++) {
				switch (sqlite3_column_type(stmt, i)) {
					case SQLITE_TEXT:
						[row addObject:[NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, i)]];
						break;
					case SQLITE_INTEGER:
						[row addObject:@(sqlite3_column_int(stmt, i))];
						break;
					case SQLITE_NULL:
						[row addObject:NSNull.null];
						break;
					default:
						[NSException
							raise:NSInternalInconsistencyException
							format:@"Received an unknown type of object from query: %@",
							query
						];
						break;
				}
				if ([columns isKindOfClass:[NSMutableArray class]]) {
					[(NSMutableArray *)columns addObject:@(sqlite3_column_name(stmt, i))];
				}
			}
			if ([columns isKindOfClass:[NSMutableArray class]]) {
				columns = columns.copy;
			}
			if (!block(columns, (id)row)) break;
		}
	}
	status = sqlite3_finalize(stmt);
	return (status == SQLITE_OK);
}