Stop storing num_params in statement

Postgres will check the count for us.

Author: sfackler

src/lib.rs

@@ -254,24 +254,22 @@ impl PostgresConnection {
             query: query,
             param_types: types
         });
+        self.write_message(&Describe { variant: 'S' as u8, name: stmt_name });
         self.write_message(&Sync);
 
-        match self.read_message() {
+        match_read_message!(self, {
             ParseComplete => (),
-            ErrorResponse { fields } =>
-                return Err(PostgresDbError::new(fields)),
+            ErrorResponse { fields } => {
+                self.wait_for_ready();
+                return Err(PostgresDbError::new(fields));
+            },
             resp => fail!("Bad response: %?", resp.to_str())
-        }
-
-        self.wait_for_ready();
-
-        self.write_message(&Describe { variant: 'S' as u8, name: stmt_name });
-        self.write_message(&Sync);
+        })
 
-        let num_params = match self.read_message() {
-            ParameterDescription { types } => types.len(),
+        match_read_message!(self, {
+            ParameterDescription {_} => (),
             resp => fail!("Bad response: %?", resp.to_str())
-        };
+        })
 
         match_read_message!(self, {
             RowDescription {_} | NoData => (),
@@ -283,7 +281,6 @@ impl PostgresConnection {
         Ok(PostgresStatement {
             conn: self,
             name: stmt_name,
-            num_params: num_params,
             next_portal_id: Cell::new(0)
         })
     }
@@ -366,7 +363,6 @@ impl<'self> PostgresTransaction<'self> {
 pub struct PostgresStatement<'self> {
     priv conn: &'self PostgresConnection,
     priv name: ~str,
-    priv num_params: uint,
     priv next_portal_id: Cell<uint>
 }
 
@@ -390,17 +386,8 @@ impl<'self> Drop for PostgresStatement<'self> {
 }
 
 impl<'self> PostgresStatement<'self> {
-    pub fn num_params(&self) -> uint {
-        self.num_params
-    }
-
     fn execute(&self, portal_name: &str, params: &[&ToSql])
                -> Option<PostgresDbError> {
-        if self.num_params != params.len() {
-            fail!("Expected %u params but got %u", self.num_params,
-                  params.len());
-        }
-
         let formats = [];
         let values: ~[Option<~[u8]>] = params.iter().map(|val| val.to_sql())
                 .collect();

src/test.rs

@@ -68,6 +68,26 @@ fn test_nulls() {
     };
 }
 
+#[test]
+fn test_wrong_num_params() {
+    let conn = PostgresConnection::connect("postgres://postgres@127.0.0.1:5432");
+
+    do conn.in_transaction |trans| {
+        trans.prepare("CREATE TABLE foo (
+                        id BIGINT PRIMARY KEY,
+                        val VARCHAR
+                      )").update([]);
+        let res = trans.prepare("INSERT INTO foo (id, val) VALUES ($1, $2), ($3, $4)")
+                .try_update([&1 as &ToSql, & &"foobar" as &ToSql]);
+        match res {
+            Err(PostgresDbError { code: ~"08P01", _ }) => (),
+            resp => fail!("Unexpected response: %?", resp)
+        }
+
+        trans.set_rollback();
+    }
+}
+
 #[test]
 fn test_plaintext_pass() {
     PostgresConnection::connect("postgres://pass_user:password@127.0.0.1:5432");
@@ -86,7 +106,7 @@ fn test_plaintext_pass_no_pass() {
 fn test_plaintext_pass_wrong_pass() {
     let ret = PostgresConnection::try_connect("postgres://pass_user:asdf@127.0.0.1:5432");
     match ret {
-        Err(DbError(PostgresDbError { code, _ })) => assert_eq!(code, ~"28P01"),
+        Err(DbError(PostgresDbError { code: ~"28P01", _ })) => (),
         ret => fail!("Unexpected result %?", ret)
     }
 }
@@ -109,7 +129,7 @@ fn test_md5_pass_no_pass() {
 fn test_md5_pass_wrong_pass() {
     let ret = PostgresConnection::try_connect("postgres://md5_user:asdf@127.0.0.1:5432");
     match ret {
-        Err(DbError(PostgresDbError { code, _ })) => assert_eq!(code, ~"28P01"),
+        Err(DbError(PostgresDbError { code: ~"28P01", _ })) => (),
         ret => fail!("Unexpected result %?", ret)
     }
 }