bugfix: fix tpcds_logical_q8 ambiguous name.

datafusion/common/src/dfschema.rs

@@ -284,12 +284,29 @@ impl DFSchema {
         match matches.len() {
             0 => Err(field_not_found(None, name, self)),
             1 => Ok(matches[0]),
-            _ => Err(DataFusionError::SchemaError(
-                SchemaError::AmbiguousReference {
-                    qualifier: None,
-                    name: name.to_string(),
-                },
-            )),
+            _ => {
+                // When `matches` size > 1, it doesn't necessarily mean an `ambiguous name` problem.
+                // Because name may generate from Alias/... . It means that it don't own qualifier.
+                // For example:
+                //             Join on id = b.id
+                // Project a.id as id   TableScan b id
+                // In this case, there isn't `ambiguous name` problem. When `matches` just contains
+                // one field without qualifier, we should return it.
+                let fields_without_qualifier = matches
+                    .iter()
+                    .filter(|f| f.qualifier.is_none())
+                    .collect::<Vec<_>>();
+                if fields_without_qualifier.len() == 1 {
+                    Ok(fields_without_qualifier[0])
+                } else {
+                    Err(DataFusionError::SchemaError(
+                        SchemaError::AmbiguousReference {
+                            qualifier: None,
+                            name: name.to_string(),
+                        },
+                    ))
+                }
+            }
         }
     }
 

datafusion/optimizer/src/utils.rs

@@ -416,7 +416,7 @@ pub fn only_or_err<T>(slice: &[T]) -> Result<&T> {
 /// Rewrites `expr` using `rewriter`, ensuring that the output has the
 /// same name as `expr` prior to rewrite, adding an alias if necessary.
 ///
-/// This is important when optimzing plans to ensure the the output
+/// This is important when optimizing plans to ensure the the output
 /// schema of plan nodes don't change after optimization
 pub fn rewrite_preserving_name<R>(expr: Expr, rewriter: &mut R) -> Result<Expr>
 where

datafusion/optimizer/tests/integration-test.rs

@@ -320,6 +320,22 @@ fn push_down_filter_groupby_expr_contains_alias() {
     assert_eq!(expected, format!("{plan:?}"));
 }
 
+#[test]
+// issue: https://github.com/apache/arrow-datafusion/issues/5334
+fn test_same_name_but_not_ambiguous() {
+    let sql = "SELECT t1.col_int32 AS col_int32 FROM test t1 intersect SELECT col_int32 FROM test t2";
+    let plan = test_sql(sql).unwrap();
+    let expected = "LeftSemi Join: col_int32 = t2.col_int32\
+    \n  Distinct:\
+    \n    Projection: t1.col_int32 AS col_int32\
+    \n      SubqueryAlias: t1\
+    \n        TableScan: test projection=[col_int32]\
+    \n  Projection: t2.col_int32\
+    \n    SubqueryAlias: t2\
+    \n      TableScan: test projection=[col_int32]";
+    assert_eq!(expected, format!("{plan:?}"));
+}
+
 fn test_sql(sql: &str) -> Result<LogicalPlan> {
     // parse the SQL
     let dialect = GenericDialect {}; // or AnsiDialect, or your own dialect ...
@@ -348,10 +364,7 @@ struct MySchemaProvider {
 }
 
 impl ContextProvider for MySchemaProvider {
-    fn get_table_provider(
-        &self,
-        name: TableReference,
-    ) -> datafusion_common::Result<Arc<dyn TableSource>> {
+    fn get_table_provider(&self, name: TableReference) -> Result<Arc<dyn TableSource>> {
         let table_name = name.table();
         if table_name.starts_with("test") {
             let schema = Schema::new_with_metadata(