Add Statement::columns

src/lib.rs

@@ -58,7 +58,7 @@ macro_rules! raise(
 macro_rules! error(
     ($connection:expr, $code:expr) => (match ::error::last($connection) {
         Some(error) => return Err(error),
-        None => return Err(::Error::from(::ErrorKind::from($code as isize))),
+        _ => return Err(::Error::from(::ErrorKind::from($code as isize))),
     });
 );
 

src/statement.rs

@@ -36,6 +36,12 @@ pub trait Value {
 }
 
 impl<'l> Statement<'l> {
+    /// Return the number of columns.
+    #[inline]
+    pub fn columns(&mut self) -> usize {
+        unsafe { ffi::sqlite3_column_count(self.raw.0) as usize }
+    }
+
     /// Bind the parameter at a specific location.
     ///
     /// The leftmost location has the index 1.

tests/lib.rs

@@ -21,6 +21,7 @@ fn workflow() {
     {
         let sql = "INSERT INTO `users` (id, name, age) VALUES (?, ?, ?)";
         let mut statement = ok!(connection.prepare(sql));
+        assert_eq!(statement.columns(), 0);
         ok!(statement.bind(1, 1i64));
         ok!(statement.bind(2, "Alice"));
         ok!(statement.bind(3, 20.99));
@@ -44,6 +45,7 @@ fn workflow() {
     {
         let sql = "SELECT * FROM `users`";
         let mut statement = ok!(connection.prepare(sql));
+        assert_eq!(statement.columns(), 3);
         assert_eq!(ok!(statement.step()), State::Row);
         assert_eq!(ok!(statement.read::<i64>(0)), 1);
         assert_eq!(ok!(statement.read::<String>(1)), String::from("Alice"));