support tuples as types

datafusion/expr/src/type_coercion/binary.rs

@@ -25,7 +25,7 @@ use crate::Operator;
 use arrow::array::{new_empty_array, Array};
 use arrow::compute::can_cast_types;
 use arrow::datatypes::{
-    DataType, Field, TimeUnit, DECIMAL128_MAX_PRECISION, DECIMAL128_MAX_SCALE,
+    DataType, Field, FieldRef, TimeUnit, DECIMAL128_MAX_PRECISION, DECIMAL128_MAX_SCALE,
     DECIMAL256_MAX_PRECISION, DECIMAL256_MAX_SCALE,
 };
 use datafusion_common::{exec_datafusion_err, plan_datafusion_err, plan_err, Result};
@@ -498,6 +498,7 @@ pub fn comparison_coercion(lhs_type: &DataType, rhs_type: &DataType) -> Option<D
         .or_else(|| string_numeric_coercion(lhs_type, rhs_type))
         .or_else(|| string_temporal_coercion(lhs_type, rhs_type))
         .or_else(|| binary_coercion(lhs_type, rhs_type))
+        .or_else(|| struct_coercion(lhs_type, rhs_type))
 }
 
 /// Coerce `lhs_type` and `rhs_type` to a common type for value exprs
@@ -780,6 +781,31 @@ fn coerce_numeric_type_to_decimal256(numeric_type: &DataType) -> Option<DataType
     }
 }
 
+fn struct_coercion(lhs_type: &DataType, rhs_type: &DataType) -> Option<DataType> {
+    use arrow::datatypes::DataType::*;
+    match (lhs_type, rhs_type) {
+        (Struct(lhs_fields), Struct(rhs_fields)) => {
+            if lhs_fields.len() != rhs_fields.len() {
+                return None;
+            }
+
+            let types = std::iter::zip(lhs_fields.iter(), rhs_fields.iter())
+                .map(|(lhs, rhs)| comparison_coercion(lhs.data_type(), rhs.data_type()))
+                .collect::<Option<Vec<DataType>>>()?;
+
+            let fields = types
+                .into_iter()
+                .enumerate()
+                .map(|(i, datatype)| {
+                    Arc::new(Field::new(format!("c{i}"), datatype, true))
+                })
+                .collect::<Vec<FieldRef>>();
+            Some(Struct(fields.into()))
+        }
+        _ => None,
+    }
+}
+
 /// Returns the output type of applying mathematics operations such as
 /// `+` to arguments of `lhs_type` and `rhs_type`.
 fn mathematics_numerical_coercion(

datafusion/sql/src/expr/mod.rs

@@ -661,6 +661,7 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
                 }
                 not_impl_err!("AnyOp not supported by ExprPlanner: {binary_expr:?}")
             }
+            SQLExpr::Tuple(values) => self.parse_tuple(schema, planner_context, values),
             _ => not_impl_err!("Unsupported ast node in sqltorel: {sql:?}"),
         }
     }
@@ -670,7 +671,7 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
         &self,
         schema: &DFSchema,
         planner_context: &mut PlannerContext,
-        values: Vec<sqlparser::ast::Expr>,
+        values: Vec<SQLExpr>,
         fields: Vec<StructField>,
     ) -> Result<Expr> {
         if !fields.is_empty() {
@@ -695,6 +696,23 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
         not_impl_err!("Struct not supported by ExprPlanner: {create_struct_args:?}")
     }
 
+    fn parse_tuple(
+        &self,
+        schema: &DFSchema,
+        planner_context: &mut PlannerContext,
+        values: Vec<SQLExpr>,
+    ) -> Result<Expr> {
+        match values.first() {
+            Some(SQLExpr::Identifier(_)) | Some(SQLExpr::Value(_)) => {
+                self.parse_struct(schema, planner_context, values, vec![])
+            }
+            None => not_impl_err!("Empty tuple not supported yet"),
+            _ => {
+                not_impl_err!("Only identifiers and literals are supported in tuples")
+            }
+        }
+    }
+
     fn sql_position_to_expr(
         &self,
         substr_expr: SQLExpr,

datafusion/sqllogictest/test_files/struct.slt

@@ -218,9 +218,6 @@ select named_struct('field_a', 1, 'field_b', 2);
 ----
 {field_a: 1, field_b: 2}
 
-statement ok
-drop table values;
-
 query T
 select arrow_typeof(named_struct('first', 1, 'second', 2, 'third', 3));
 ----
@@ -236,3 +233,44 @@ query ?
 select {'animal': {'cat': 1, 'dog': 2, 'bird': {'parrot': 3, 'canary': 1}}, 'genre': {'fiction': ['mystery', 'sci-fi', 'fantasy'], 'non-fiction': {'biography': 5, 'history': 7, 'science': {'physics': 2, 'biology': 3}}}, 'vehicle': {'car': {'sedan': 4, 'suv': 2}, 'bicycle': 3, 'boat': ['sailboat', 'motorboat']}, 'weather': {'sunny': True, 'temperature': 25.5, 'wind': {'speed': 10, 'direction': 'NW'}}};
 ----
 {animal: {cat: 1, dog: 2, bird: {parrot: 3, canary: 1}}, genre: {fiction: [mystery, sci-fi, fantasy], non-fiction: {biography: 5, history: 7, science: {physics: 2, biology: 3}}}, vehicle: {car: {sedan: 4, suv: 2}, bicycle: 3, boat: [sailboat, motorboat]}, weather: {sunny: true, temperature: 25.5, wind: {speed: 10, direction: NW}}}
+
+# test tuple as struct
+query B
+select ('x', 'y') = ('x', 'y');
+----
+true
+
+query B
+select ('x', 'y') = ('y', 'x');
+----
+false
+
+query error DataFusion error: Error during planning: Cannot infer common argument type for comparison operation Struct.*
+select ('x', 'y') = ('x', 'y', 'z');
+
+query B
+select ('x', 'y') IN (('x', 'y'));
+----
+true
+
+query B
+select ('x', 'y') IN (('x', 'y'), ('y', 'x'));
+----
+true
+
+query I
+select a from values where (a, c) = (1, 'a');
+----
+1
+
+query I
+select a from values where (a, c) IN ((1, 'a'), (2, 'b'));
+----
+1
+2
+
+statement ok
+drop table values;
+
+statement ok
+drop table struct_values;