Include column ID in error

Closes #514

Author: sfackler

tokio-postgres/src/error/mod.rs

@@ -336,7 +336,7 @@ enum Kind {
     Tls,
     ToSql(usize),
     FromSql(usize),
-    Column,
+    Column(String),
     CopyInStream,
     Closed,
     Db,
@@ -369,13 +369,13 @@ impl fmt::Debug for Error {
 
 impl fmt::Display for Error {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self.0.kind {
+        match &self.0.kind {
             Kind::Io => fmt.write_str("error communicating with the server")?,
             Kind::UnexpectedMessage => fmt.write_str("unexpected message from server")?,
             Kind::Tls => fmt.write_str("error performing TLS handshake")?,
             Kind::ToSql(idx) => write!(fmt, "error serializing parameter {}", idx)?,
             Kind::FromSql(idx) => write!(fmt, "error deserializing column {}", idx)?,
-            Kind::Column => fmt.write_str("invalid column")?,
+            Kind::Column(column) => write!(fmt, "invalid column `{}`", column)?,
             Kind::CopyInStream => fmt.write_str("error from a copy_in stream")?,
             Kind::Closed => fmt.write_str("connection closed")?,
             Kind::Db => fmt.write_str("db error")?,
@@ -454,8 +454,8 @@ impl Error {
         Error::new(Kind::FromSql(idx), Some(e))
     }
 
-    pub(crate) fn column() -> Error {
-        Error::new(Kind::Column, None)
+    pub(crate) fn column(column: String) -> Error {
+        Error::new(Kind::Column(column), None)
     }
 
     pub(crate) fn copy_in_stream<E>(e: E) -> Error

tokio-postgres/src/row.rs

@@ -146,20 +146,20 @@ impl Row {
     /// Like `Row::get`, but returns a `Result` rather than panicking.
     pub fn try_get<'a, I, T>(&'a self, idx: I) -> Result<T, Error>
     where
-        I: RowIndex,
+        I: RowIndex + fmt::Display,
         T: FromSql<'a>,
     {
         self.get_inner(&idx)
     }
 
     fn get_inner<'a, I, T>(&'a self, idx: &I) -> Result<T, Error>
     where
-        I: RowIndex,
+        I: RowIndex + fmt::Display,
         T: FromSql<'a>,
     {
         let idx = match idx.__idx(self.columns()) {
             Some(idx) => idx,
-            None => return Err(Error::column()),
+            None => return Err(Error::column(idx.to_string())),
         };
 
         let ty = self.columns()[idx].type_();
@@ -223,18 +223,18 @@ impl SimpleQueryRow {
     /// Like `SimpleQueryRow::get`, but returns a `Result` rather than panicking.
     pub fn try_get<I>(&self, idx: I) -> Result<Option<&str>, Error>
     where
-        I: RowIndex,
+        I: RowIndex + fmt::Display,
     {
         self.get_inner(&idx)
     }
 
     fn get_inner<I>(&self, idx: &I) -> Result<Option<&str>, Error>
     where
-        I: RowIndex,
+        I: RowIndex + fmt::Display,
     {
         let idx = match idx.__idx(&self.columns) {
             Some(idx) => idx,
-            None => return Err(Error::column()),
+            None => return Err(Error::column(idx.to_string())),
         };
 
         let buf = self.ranges[idx].clone().map(|r| &self.body.buffer()[r]);