Merge pull request #7307 from leiysky/fix/duplicated-create-table-column

Author: sundy-li

src/query/service/src/sql/planner/binder/ddl/table.rs

@@ -376,7 +376,9 @@ impl<'a> Binder {
                         )
                     })
                     .collect();
-                (DataSchemaRefExt::create(fields), vec![])
+                let schema = DataSchemaRefExt::create(fields);
+                Self::validate_create_table_schema(&schema)?;
+                (schema, vec![])
             }
             (Some(source), Some(query)) => {
                 // e.g. `CREATE TABLE t (i INT) AS SELECT * from old_t` with columns speicified
@@ -396,10 +398,9 @@ impl<'a> Binder {
                     .collect();
                 let source_fields = source_schema.fields().clone();
                 let source_fields = self.concat_fields(source_fields, query_fields);
-                (
-                    DataSchemaRefExt::create(source_fields.to_vec()),
-                    source_coments,
-                )
+                let schema = DataSchemaRefExt::create(source_fields);
+                Self::validate_create_table_schema(&schema)?;
+                (schema, source_coments)
             }
             _ => Err(ErrorCode::BadArguments(
                 "Incorrect CREATE query: required list of column descriptions or AS section or SELECT..",
@@ -784,7 +785,9 @@ impl<'a> Binder {
                     fields.push(field);
                     fields_comments.push(column.comment.clone().unwrap_or_default());
                 }
-                Ok((DataSchemaRefExt::create(fields), fields_comments))
+                let schema = DataSchemaRefExt::create(fields);
+                Self::validate_create_table_schema(&schema)?;
+                Ok((schema, fields_comments))
             }
             CreateTableSource::Like {
                 catalog,
@@ -806,6 +809,22 @@ impl<'a> Binder {
         }
     }
 
+    /// Validate the schema of the table to be created.
+    fn validate_create_table_schema(schema: &DataSchemaRef) -> Result<()> {
+        // Check if there are duplicated column names
+        let mut name_set = HashSet::new();
+        for field in schema.fields() {
+            if !name_set.insert(field.name().clone()) {
+                return Err(ErrorCode::BadArguments(format!(
+                    "Duplicated column name: {}",
+                    field.name()
+                )));
+            }
+        }
+
+        Ok(())
+    }
+
     fn insert_table_option_with_validation(
         &self,
         options: &mut BTreeMap<String, String>,

tests/logictest/suites/base/05_ddl/05_0000_ddl_create_tables

@@ -218,3 +218,17 @@ DROP DATABASE db2;
 statement error 1002
 CREATE TABLE system.test(a INT);
 
+statement ok
+drop table if exists t;
+
+statement error Duplicated column name
+create table t(a int, a int);
+
+statement error Duplicated column name
+create table t(a int, A int);
+
+statement error Duplicated column name
+create table t("A" int, "A" int);
+
+statement error Duplicated column name
+create table t as select number, number from numbers(1);