feat(sql-udf): introduce udf_binding_flag

src/frontend/src/binder/expr/column.rs

@@ -45,8 +45,18 @@ impl Binder {
         // to the name of the defined sql udf parameters stored in `udf_context`.
         // If so, we will treat this bind as an special bind, the actual expression
         // stored in `udf_context` will then be bound instead of binding the non-existing column.
-        if let Some(expr) = self.udf_context.get_expr(&column_name) {
-            return Ok(expr.clone());
+        if self.udf_binding_flag {
+            if let Some(expr) = self.udf_context.get_expr(&column_name) {
+                return Ok(expr.clone());
+            } else {
+                // The reason that we directly return error here,
+                // is because during a valid sql udf binding,
+                // there will not exist any column identifiers
+                return Err(ErrorCode::BindError(format!(
+                    "failed to find named parameter {column_name}"
+                ))
+                .into());
+            }
         }
 
         match self

src/frontend/src/binder/expr/function.rs

@@ -239,7 +239,10 @@ impl Binder {
                 }
 
                 if let Ok(expr) = UdfContext::extract_udf_expression(ast) {
+                    self.set_udf_binding_flag();
                     let bind_result = self.bind_expr(expr);
+                    self.unset_udf_binding_flag();
+
                     // Restore context information for subsequent binding
                     self.udf_context.update_context(stashed_udf_context);
                     return bind_result;

src/frontend/src/binder/mod.rs

@@ -122,9 +122,12 @@ pub struct Binder {
 
     /// The sql udf context that will be used during binding phase
     udf_context: UdfContext,
+
+    /// Udf binding flag, used to distinguish between
+    /// columns and named parameters during sql udf binding
+    udf_binding_flag: bool,
 }
 
-#[derive(Clone, Debug, Default)]
 pub struct UdfContext {
     /// The mapping from `sql udf parameters` to a bound `ExprImpl` generated from `ast expressions`
     /// Note: The expressions are constructed during runtime, correspond to the actual users' input
@@ -340,6 +343,7 @@ impl Binder {
             included_relations: HashSet::new(),
             param_types: ParameterTypes::new(param_types),
             udf_context: UdfContext::new(),
+            udf_binding_flag: false,
         }
     }
 
@@ -489,6 +493,14 @@ impl Binder {
     pub fn udf_context_mut(&mut self) -> &mut UdfContext {
         &mut self.udf_context
     }
+
+    pub fn set_udf_binding_flag(&mut self) {
+        self.udf_binding_flag = true;
+    }
+
+    pub fn unset_udf_binding_flag(&mut self) {
+        self.udf_binding_flag = false;
+    }
 }
 
 /// The column name stored in [`BindContext`] for a column without an alias.