Add related source code locations to errors

datafusion/common/src/column.rs

@@ -17,23 +17,33 @@
 
 //! Column
 
-use arrow_schema::{Field, FieldRef};
-
 use crate::error::_schema_err;
 use crate::utils::{parse_identifiers_normalized, quote_identifier};
-use crate::{DFSchema, Result, SchemaError, TableReference};
+use crate::{DFSchema, Diagnostic, Result, SchemaError, Spans, TableReference};
+use arrow_schema::{Field, FieldRef};
 use std::collections::HashSet;
 use std::convert::Infallible;
 use std::fmt;
 use std::str::FromStr;
 
 /// A named reference to a qualified field in a schema.
-#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
+#[derive(Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct Column {
     /// relation/table reference.
     pub relation: Option<TableReference>,
     /// field/column name.
     pub name: String,
+    /// Original source code location, if known
+    pub spans: Spans,
+}
+
+impl fmt::Debug for Column {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Column")
+            .field("relation", &self.relation)
+            .field("name", &self.name)
+            .finish()
+    }
 }
 
 impl Column {
@@ -50,6 +60,7 @@ impl Column {
         Self {
             relation: relation.map(|r| r.into()),
             name: name.into(),
+            spans: Spans::new(),
         }
     }
 
@@ -58,6 +69,7 @@ impl Column {
         Self {
             relation: None,
             name: name.into(),
+            spans: Spans::new(),
         }
     }
 
@@ -68,6 +80,7 @@ impl Column {
         Self {
             relation: None,
             name: name.into(),
+            spans: Spans::new(),
         }
     }
 
@@ -99,7 +112,11 @@ impl Column {
             // identifiers will be treated as an unqualified column name
             _ => return None,
         };
-        Some(Self { relation, name })
+        Some(Self {
+            relation,
+            name,
+            spans: Spans::new(),
+        })
     }
 
     /// Deserialize a fully qualified name string into a column
@@ -113,6 +130,7 @@ impl Column {
             Self {
                 relation: None,
                 name: flat_name,
+                spans: Spans::new(),
             },
         )
     }
@@ -124,6 +142,7 @@ impl Column {
             Self {
                 relation: None,
                 name: flat_name,
+                spans: Spans::new(),
             },
         )
     }
@@ -239,7 +258,30 @@ impl Column {
 
                     // If not due to USING columns then due to ambiguous column name
                     return _schema_err!(SchemaError::AmbiguousReference {
-                        field: Column::new_unqualified(self.name),
+                        field: Column::new_unqualified(&self.name),
+                    })
+                    .map_err(|err| {
+                        let mut diagnostic = Diagnostic::new_error(
+                            format!("column '{}' is ambiguous", &self.name),
+                            self.spans().first(),
+                        );
+                        // TODO If [`DFSchema`] had spans, we could show the
+                        // user which columns are candidates, or which table
+                        // they come from. For now, let's list the table names
+                        // only.
+                        for qualified_field in qualified_fields {
+                            let (Some(table), _) = qualified_field else {
+                                continue;
+                            };
+                            diagnostic.add_note(
+                                format!(
+                                    "possible reference to '{}' in table '{}'",
+                                    &self.name, table
+                                ),
+                                None,
+                            );
+                        }
+                        err.with_diagnostic(diagnostic)
                     });
                 }
             }
@@ -254,6 +296,33 @@ impl Column {
                 .collect(),
         })
     }
+
+    /// Returns a reference to the set of locations in the SQL query where this
+    /// column appears, if known.
+    pub fn spans(&self) -> &Spans {
+        &self.spans
+    }
+
+    /// Returns a mutable reference to the set of locations in the SQL query
+    /// where this column appears, if known.
+    pub fn spans_mut(&mut self) -> &mut Spans {
+        &mut self.spans
+    }
+
+    /// Replaces the set of locations in the SQL query where this column
+    /// appears, if known.
+    pub fn with_spans(mut self, spans: Spans) -> Self {
+        self.spans = spans;
+        self
+    }
+
+    /// Qualifies the column with the given table reference.
+    pub fn with_relation(&self, relation: TableReference) -> Self {
+        Self {
+            relation: Some(relation),
+            ..self.clone()
+        }
+    }
 }
 
 impl From<&str> for Column {

datafusion/common/src/config.rs

@@ -250,6 +250,11 @@ config_namespace! {
         /// specified. The Arrow type system does not have a notion of maximum
         /// string length and thus DataFusion can not enforce such limits.
         pub support_varchar_with_length: bool, default = true
+
+        /// When set to true, the source locations relative to the original SQL
+        /// query (i.e. [`Span`](sqlparser::tokenizer::Span)) will be collected
+        /// and recorded in the logical plan nodes.
+        pub collect_spans: bool, default = false
     }
 }
 

datafusion/common/src/dfschema.rs

@@ -502,10 +502,7 @@ impl DFSchema {
                     Ok((fields_without_qualifier[0].0, fields_without_qualifier[0].1))
                 } else {
                     _schema_err!(SchemaError::AmbiguousReference {
-                        field: Column {
-                            relation: None,
-                            name: name.to_string(),
-                        },
+                        field: Column::new_unqualified(name.to_string(),),
                     })
                 }
             }