Subquery alias bindings (apache#269)

* Subquey alias bindings

* newline formatting for subquery alias Display function

* reorder imports

datafusion/__init__.py

@@ -77,6 +77,7 @@
     TryCast,
     Between,
     Explain,
+    SubqueryAlias,
     Extension,
 )
 
@@ -130,6 +131,7 @@
     "TryCast",
     "Between",
     "Explain",
+    "SubqueryAlias",
     "Extension",
 ]
 

datafusion/tests/test_imports.py

@@ -76,6 +76,7 @@
     Case,
     Cast,
     TryCast,
+    SubqueryAlias,
     Between,
     Explain,
     Extension,
@@ -145,6 +146,7 @@ def test_class_module_is_datafusion():
         Cast,
         TryCast,
         Between,
+        SubqueryAlias,
         Explain,
         Extension,
     ]:

src/expr.rs

@@ -70,6 +70,7 @@ pub mod scalar_variable;
 pub mod signature;
 pub mod sort;
 pub mod subquery;
+pub mod subquery_alias;
 pub mod table_scan;
 pub mod union;
 
@@ -277,5 +278,6 @@ pub(crate) fn init_module(m: &PyModule) -> PyResult<()> {
     m.add_class::<filter::PyFilter>()?;
     m.add_class::<projection::PyProjection>()?;
     m.add_class::<table_scan::PyTableScan>()?;
+    m.add_class::<subquery_alias::PySubqueryAlias>()?;
     Ok(())
 }

src/expr/subquery_alias.rs

@@ -0,0 +1,91 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use std::fmt::{self, Display, Formatter};
+
+use datafusion_expr::SubqueryAlias;
+use pyo3::prelude::*;
+
+use crate::{common::df_schema::PyDFSchema, sql::logical::PyLogicalPlan};
+
+use super::logical_node::LogicalNode;
+
+#[pyclass(name = "SubqueryAlias", module = "datafusion.expr", subclass)]
+#[derive(Clone)]
+pub struct PySubqueryAlias {
+    subquery_alias: SubqueryAlias,
+}
+
+impl From<PySubqueryAlias> for SubqueryAlias {
+    fn from(subquery_alias: PySubqueryAlias) -> Self {
+        subquery_alias.subquery_alias
+    }
+}
+
+impl From<SubqueryAlias> for PySubqueryAlias {
+    fn from(subquery_alias: SubqueryAlias) -> PySubqueryAlias {
+        PySubqueryAlias { subquery_alias }
+    }
+}
+
+impl Display for PySubqueryAlias {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(
+            f,
+            "SubqueryAlias
+            Inputs(s): {:?}
+            Alias: {:?}
+            Schema: {:?}",
+            self.subquery_alias.input, self.subquery_alias.alias, self.subquery_alias.schema,
+        )
+    }
+}
+
+#[pymethods]
+impl PySubqueryAlias {
+    /// Retrieves the input `LogicalPlan` to this `Projection` node
+    fn input(&self) -> PyResult<Vec<PyLogicalPlan>> {
+        Ok(Self::inputs(self))
+    }
+
+    /// Resulting Schema for this `Projection` node instance
+    fn schema(&self) -> PyResult<PyDFSchema> {
+        Ok((*self.subquery_alias.schema).clone().into())
+    }
+
+    fn alias(&self) -> PyResult<String> {
+        Ok(self.subquery_alias.alias.clone())
+    }
+
+    fn __repr__(&self) -> PyResult<String> {
+        Ok(format!("SubqueryAlias({})", self))
+    }
+
+    fn __name__(&self) -> PyResult<String> {
+        Ok("SubqueryAlias".to_string())
+    }
+}
+
+impl LogicalNode for PySubqueryAlias {
+    fn inputs(&self) -> Vec<PyLogicalPlan> {
+        vec![PyLogicalPlan::from((*self.subquery_alias.input).clone())]
+    }
+
+    fn to_variant(&self, py: Python) -> PyResult<PyObject> {
+        Ok(self.clone().into_py(py))
+    }
+}