feat: Support replacing existing table relations

_duckdb-stubs/__init__.pyi

@@ -547,7 +547,7 @@ class DuckDBPyRelation:
     def count(
         self, expression: str, groups: str = "", window_spec: str = "", projected_columns: str = ""
     ) -> DuckDBPyRelation: ...
-    def create(self, table_name: str) -> None: ...
+    def create(self, table_name: str, replace: bool = False) -> None: ...
     def create_view(self, view_name: str, replace: bool = True) -> DuckDBPyRelation: ...
     def cross(self, other_rel: DuckDBPyRelation) -> DuckDBPyRelation: ...
     def cume_dist(self, window_spec: str, projected_columns: str = "") -> DuckDBPyRelation: ...

src/duckdb_py/include/duckdb_python/pyrelation.hpp

@@ -239,7 +239,7 @@ struct DuckDBPyRelation {
 	void Insert(const py::object &params = py::list()) const;
 	void Update(const py::object &set, const py::object &where = py::none());
 
-	void Create(const string &table);
+	void Create(const string &table, bool replace = false);
 
 	py::str Type();
 	py::list Columns();

src/duckdb_py/pyrelation.cpp

@@ -1,5 +1,6 @@
 #include "duckdb_python/pybind11/pybind_wrapper.hpp"
 #include "duckdb_python/pyrelation.hpp"
+#include "duckdb/common/enums/on_create_conflict.hpp"
 #include "duckdb_python/pyconnection/pyconnection.hpp"
 #include "duckdb_python/pytype.hpp"
 #include "duckdb_python/pyresult.hpp"
@@ -1648,10 +1649,11 @@ void DuckDBPyRelation::Insert(const py::object &params) const {
 	rel->Insert(values);
 }
 
-void DuckDBPyRelation::Create(const string &table) {
+void DuckDBPyRelation::Create(const string &table, bool replace) {
 	AssertRelation();
 	auto parsed_info = QualifiedName::Parse(table);
-	auto create = rel->CreateRel(parsed_info.schema, parsed_info.name, false);
+	auto on_conflict = replace ? OnCreateConflict::REPLACE_ON_CONFLICT : OnCreateConflict::ERROR_ON_CONFLICT;
+	auto create = rel->CreateRel(parsed_info.schema, parsed_info.name, false, on_conflict);
 	PyExecuteRelation(create);
 }
 

src/duckdb_py/pyrelation/initialize.cpp

@@ -330,7 +330,7 @@ void DuckDBPyRelation::Initialize(py::handle &m) {
 
 	DefineMethod({"create", "to_table"}, relation_module, &DuckDBPyRelation::Create,
 	             "Creates a new table named table_name with the contents of the relation object",
-	             py::arg("table_name"));
+	             py::arg("table_name"), py::arg("replace") = false);
 
 	DefineMethod({"create_view", "to_view"}, relation_module, &DuckDBPyRelation::CreateView,
 	             "Creates a view named view_name that refers to the relation object", py::arg("view_name"),

tests/fast/test_relation.py

@@ -172,16 +172,73 @@ def test_except_operator(self):
 
     def test_create_operator(self):
         conn = duckdb.connect()
+
         test_df = pd.DataFrame.from_dict({"i": [1, 2, 3, 4], "j": ["one", "two", "three", "four"]})
         rel = conn.from_df(test_df)
         rel.create("test_df")
+
         assert conn.query("select * from test_df").execute().fetchall() == [
             (1, "one"),
             (2, "two"),
             (3, "three"),
             (4, "four"),
         ]
 
+    def test_create_replace_false(self):
+        conn = duckdb.connect()
+
+        test_df = pd.DataFrame.from_dict({"i": [1, 2, 3], "j": ["a", "b", "c"]})
+        rel = conn.from_df(test_df)
+        rel.create("test_replace_tbl", replace=False)
+
+        assert conn.query("select * from test_replace_tbl").execute().fetchall() == [
+            (1, "a"),
+            (2, "b"),
+            (3, "c"),
+        ]
+
+    def test_create_replace_true_different_schema(self):
+        conn = duckdb.connect()
+
+        test_df = pd.DataFrame.from_dict({"i": [1, 2, 3], "j": ["a", "b", "c"]})
+        rel = conn.from_df(test_df)
+        rel.create("test_replace_tbl", replace=True)
+
+        assert conn.query("select * from test_replace_tbl").execute().fetchall() == [
+            (1, "a"),
+            (2, "b"),
+            (3, "c"),
+        ]
+
+        test_df2 = pd.DataFrame.from_dict({"a": [10, 20], "b": ["x", "y"], "c": [1.5, 2.5]})
+        rel2 = conn.from_df(test_df2)
+        rel2.create("test_replace_tbl", replace=True)
+
+        assert conn.query("select * from test_replace_tbl").execute().fetchall() == [
+            (10, "x", 1.5),
+            (20, "y", 2.5),
+        ]
+
+    def test_create_replace_false_error_on_existing(self):
+        conn = duckdb.connect()
+
+        test_df = pd.DataFrame.from_dict({"i": [1], "j": ["a"]})
+        rel = conn.from_df(test_df)
+        rel.create("test_replace_existing_tbl")
+
+        with pytest.raises(duckdb.CatalogException):
+            rel.create("test_replace_existing_tbl", replace=False)
+
+    def test_create_replace_true_error_on_non_existent(self):
+        conn = duckdb.connect()
+
+        test_df = pd.DataFrame.from_dict({"i": [1], "j": ["a"]})
+        rel = conn.from_df(test_df)
+        conn.execute("drop table if exists test_replace_tbl2")
+        rel.create("test_replace_tbl2", replace=True)
+
+        assert conn.query("select * from test_replace_tbl2").execute().fetchall() == [(1, "a")]
+
     def test_create_view_operator(self):
         conn = duckdb.connect()
         test_df = pd.DataFrame.from_dict({"i": [1, 2, 3, 4], "j": ["one", "two", "three", "four"]})