feat(duckdb): support registering external postgres tables with duckdb

ibis/backends/duckdb/__init__.py

@@ -119,6 +119,18 @@ def _s3(full_path, table_name=None):
     return table_name, dataset, []
 
 
+@_generate_view_code.register(r"postgres(ql)?://.+", priority=10)
+def _postgres(uri, table_name=None):
+    if table_name is None:
+        raise ValueError("`table_name` is required when registering a postgres table")
+    quoted_table_name = _quote(table_name)
+    sql = (
+        f"CREATE OR REPLACE VIEW {quoted_table_name} AS "
+        f"SELECT * FROM postgres_scan_pushdown('{uri}', 'public', '{table_name}')"
+    )
+    return sql, table_name, ["postgres_scanner"]
+
+
 @_generate_view_code.register(r".+", priority=1)
 def _default(path, **kwargs):
     raise ValueError(

ibis/backends/duckdb/tests/test_register.py

@@ -229,3 +229,18 @@ def test_temp_directory(tmp_path):
 def test_s3_parquet(path):
     with pytest.raises(OSError):
         _generate_view_code(path)
+
+
+@pytest.mark.parametrize("scheme", ["postgres", "postgresql"])
+@pytest.mark.parametrize(
+    "name, quoted_name", [("test", "test"), ("my table", '"my table"')]
+)
+def test_postgres(scheme, name, quoted_name):
+    uri = f"{scheme}://username:password@localhost:5432"
+    sql, table_name, exts = _generate_view_code(uri, name)
+    assert sql == (
+        f"CREATE OR REPLACE VIEW {quoted_name} AS "
+        f"SELECT * FROM postgres_scan_pushdown('{uri}', 'public', '{name}')"
+    )
+    assert table_name == name
+    assert exts == ["postgres_scanner"]