Allow named parameters to be omitted.

If the parameters have never been bound, they default to `NULL`. If they
have previously been bound, they keep the existing value.
This commit is contained in:
John Gallagher 2015-12-11 16:34:58 -05:00
parent 489b7df451
commit 5fdb2e1fda

View File

@ -68,7 +68,10 @@ impl<'conn> SqliteStatement<'conn> {
})
}
/// Execute the prepared statement with named parameter(s).
/// Execute the prepared statement with named parameter(s). If any parameters
/// that were in the prepared statement are not included in `params`, they
/// will continue to use the most-recently bound value from a previous call
/// to `execute_named`, or `NULL` if they have never been bound.
///
/// On success, returns the number of rows that were changed or inserted or deleted (via
/// `sqlite3_changes`).
@ -95,7 +98,9 @@ impl<'conn> SqliteStatement<'conn> {
}
/// Execute the prepared statement with named parameter(s), returning an iterator over the
/// resulting rows.
/// resulting rows. If any parameters that were in the prepared statement are not included in
/// `params`, they will continue to use the most-recently bound value from a previous call to
/// `query_named`, or `NULL` if they have never been bound.
///
/// ## Example
///
@ -125,25 +130,6 @@ impl<'conn> SqliteStatement<'conn> {
}
fn bind_parameters_named(&mut self, params: &[(&str, &ToSql)]) -> SqliteResult<()> {
// Always check that the number of parameters is correct.
assert!(params.len() as c_int == unsafe { ffi::sqlite3_bind_parameter_count(self.stmt) },
"incorrect number of parameters to query(): expected {}, got {}",
unsafe { ffi::sqlite3_bind_parameter_count(self.stmt) },
params.len());
// In debug, also sanity check that we got distinct parameter names.
debug_assert!({
use std::collections::HashSet;
let mut s = HashSet::with_capacity(params.len());
for &(name, _) in params {
s.insert(name);
}
s.len() == params.len()
},
"named parameters must be unique");
for &(name, value) in params {
if let Some(i) = try!(self.parameter_index(name)) {
try!(self.conn.decode_result(unsafe { value.bind_parameter(self.stmt, i) }));
@ -208,21 +194,31 @@ mod test {
}
#[test]
#[should_panic]
fn test_panic_on_incorrect_number_of_parameters() {
fn test_unbound_parameters_are_null() {
let db = SqliteConnection::open_in_memory().unwrap();
let sql = "CREATE TABLE test (x TEXT, y TEXT)";
db.execute_batch(sql).unwrap();
let mut stmt = db.prepare("SELECT 1 WHERE 1 = :one AND 2 = :two").unwrap();
let _ = stmt.query_named(&[(":one", &1i32)]);
let mut stmt = db.prepare("INSERT INTO test (x, y) VALUES (:x, :y)").unwrap();
stmt.execute_named(&[(":x", &"one")]).unwrap();
let result = db.query_row("SELECT y FROM test WHERE x = 'one'", &[],
|row| row.get::<Option<String>>(0)).unwrap();
assert!(result.is_none());
}
#[test]
#[cfg(debug_assertions)]
#[should_panic]
fn test_debug_panic_on_incorrect_parameter_names() {
fn test_unbound_parameters_are_reused() {
let db = SqliteConnection::open_in_memory().unwrap();
let sql = "CREATE TABLE test (x TEXT, y TEXT)";
db.execute_batch(sql).unwrap();
let mut stmt = db.prepare("SELECT 1 WHERE 1 = :one AND 2 = :two").unwrap();
let _ = stmt.query_named(&[(":one", &1i32), (":one", &2i32)]);
let mut stmt = db.prepare("INSERT INTO test (x, y) VALUES (:x, :y)").unwrap();
stmt.execute_named(&[(":x", &"one")]).unwrap();
stmt.execute_named(&[(":y", &"two")]).unwrap();
let result = db.query_row("SELECT x FROM test WHERE y = 'two'", &[],
|row| row.get::<String>(0)).unwrap();
assert_eq!(result, "one");
}
}