diff --git a/src/convenient.rs b/src/convenient.rs new file mode 100644 index 0000000..202c964 --- /dev/null +++ b/src/convenient.rs @@ -0,0 +1,72 @@ +use super::ffi; + +use {Error, Result, Statement}; +use types::ToSql; + +impl<'conn> Statement<'conn> { + /// Execute an INSERT and return the ROWID. + /// + /// # Failure + /// Will return `Err` if no row is inserted or many rows are inserted. + pub fn insert(&mut self, params: &[&ToSql]) -> Result { + let changes = try!(self.execute(params)); + match changes { + 1 => Ok(self.conn.last_insert_rowid()), + _ => Err(Error::QueryInsertedRows(changes)) + } + } + + /// Return `true` if a query in the SQL statement it executes returns one or more rows + /// and `false` if the SQL returns an empty set. + pub fn exists(&mut self, params: &[&ToSql]) -> Result { + self.reset_if_needed(); + unsafe { + try!(self.bind_parameters(params)); + let r = ffi::sqlite3_step(self.stmt); + ffi::sqlite3_reset(self.stmt); + match r { + ffi::SQLITE_DONE => Ok(false), + ffi::SQLITE_ROW => Ok(true), + _ => Err(self.conn.decode_result(r).unwrap_err()), + } + } + } +} + +#[cfg(test)] +mod test { + use {Connection, Error}; + + #[test] + fn test_insert() { + let db = Connection::open_in_memory().unwrap(); + db.execute_batch("CREATE TABLE foo(x INTEGER UNIQUE)").unwrap(); + let mut stmt = db.prepare("INSERT OR IGNORE INTO foo (x) VALUES (?)").unwrap(); + assert_eq!(stmt.insert(&[&1i32]).unwrap(), 1); + assert_eq!(stmt.insert(&[&2i32]).unwrap(), 2); + match stmt.insert(&[&1i32]).unwrap_err() { + Error::QueryInsertedRows(0) => (), + err => panic!("Unexpected error {}", err), + } + let mut multi = db.prepare("INSERT INTO foo (x) SELECT 3 UNION ALL SELECT 4").unwrap(); + match multi.insert(&[]).unwrap_err() { + Error::QueryInsertedRows(2) => (), + err => panic!("Unexpected error {}", err), + } + } + + #[test] + fn test_exists() { + let db = Connection::open_in_memory().unwrap(); + let sql = "BEGIN; + CREATE TABLE foo(x INTEGER); + INSERT INTO foo VALUES(1); + INSERT INTO foo VALUES(2); + END;"; + db.execute_batch(sql).unwrap(); + let mut stmt = db.prepare("SELECT 1 FROM foo WHERE x = ?").unwrap(); + assert!(stmt.exists(&[&1i32]).unwrap()); + assert!(stmt.exists(&[&2i32]).unwrap()); + assert!(!stmt.exists(&[&0i32]).unwrap()); + } +} \ No newline at end of file diff --git a/src/error.rs b/src/error.rs index ba93df8..2f7ce45 100644 --- a/src/error.rs +++ b/src/error.rs @@ -66,6 +66,9 @@ pub enum Error { #[cfg(feature = "functions")] #[allow(dead_code)] UserFunctionError(Box), + + /// Error when a query that was expected to insert one row did not insert any or insert many. + QueryInsertedRows(c_int), } impl From for Error { @@ -102,6 +105,8 @@ impl fmt::Display for Error { &Error::InvalidFunctionParameterType => write!(f, "Invalid function parameter type"), #[cfg(feature = "functions")] &Error::UserFunctionError(ref err) => err.fmt(f), + + &Error::QueryInsertedRows(i) => write!(f, "Query inserted {} rows", i), } } } @@ -128,6 +133,8 @@ impl error::Error for Error { &Error::InvalidFunctionParameterType => "invalid function parameter type", #[cfg(feature = "functions")] &Error::UserFunctionError(ref err) => err.description(), + + &Error::QueryInsertedRows(_) => "query inserted zero or more than one row", } } @@ -151,6 +158,8 @@ impl error::Error for Error { &Error::InvalidFunctionParameterType => None, #[cfg(feature = "functions")] &Error::UserFunctionError(ref err) => Some(&**err), + + &Error::QueryInsertedRows(_) => None, } } }