fix(planner): consider NULL in type checker

databendlabs · Jun 17, 2022 · da5c10d · da5c10d
1 parent 400fd52
commit da5c10d
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Showing 2 changed files with 16 additions and 3 deletions.
diff --git a/query/src/sql/planner/plans/scalar.rs b/query/src/sql/planner/plans/scalar.rs
@@ -16,6 +16,7 @@ use common_ast::ast::BinaryOperator;
 use common_datavalues::BooleanType;
 use common_datavalues::DataTypeImpl;
 use common_datavalues::DataValue;
+use common_datavalues::NullType;
 use common_exception::ErrorCode;
 use common_exception::Result;
 use common_functions::scalars::FunctionFactory;
@@ -410,7 +411,13 @@ pub struct ComparisonExpr {
 
 impl ScalarExpr for ComparisonExpr {
     fn data_type(&self) -> DataTypeImpl {
-        BooleanType::new_impl()
+        let mut data_type = BooleanType::new_impl();
+        if self.left.data_type() == DataTypeImpl::Null(NullType {})
+            || self.right.data_type() == DataTypeImpl::Null(NullType {})
+        {
+            data_type = NullType::new_impl();
+        }
+        data_type
     }
 
     fn used_columns(&self) -> ColumnSet {

diff --git a/query/src/sql/planner/semantic/type_check.rs b/query/src/sql/planner/semantic/type_check.rs
@@ -65,6 +65,7 @@ use crate::sql::plans::Scalar;
 use crate::sql::plans::SubqueryExpr;
 use crate::sql::plans::SubqueryType;
 use crate::sql::BindContext;
+use crate::sql::ScalarExpr;
 
 /// A helper for type checking.
 ///
@@ -650,15 +651,20 @@ impl<'a> TypeChecker<'a> {
                 let op = ComparisonOp::try_from(op)?;
                 let (left, _) = self.resolve(left, None).await?;
                 let (right, _) = self.resolve(right, None).await?;
-
+                let mut data_type = BooleanType::new_impl();
+                if left.data_type() == DataTypeImpl::Null(NullType {})
+                    || right.data_type() == DataTypeImpl::Null(NullType {})
+                {
+                    data_type = NullType::new_impl();
+                }
                 Ok((
                     ComparisonExpr {
                         op,
                         left: Box::new(left),
                         right: Box::new(right),
                     }
                     .into(),
-                    BooleanType::new_impl(),
+                    data_type,
                 ))
             }
             BinaryOperator::And => {