feat(clickhouse): add support for .sql methods

ibis/backends/clickhouse/__init__.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import ast
+import atexit
 import glob
 import json
 from contextlib import closing, suppress
@@ -167,6 +168,7 @@ def do_connect(
             compress=compression,
             **kwargs,
         )
+        self._temp_views = set()
 
     @property
     def version(self) -> str:
@@ -733,3 +735,27 @@ def _load_into_cache(self, name, expr):
 
     def _clean_up_cached_table(self, op):
         self.drop_table(op.name)
+
+    def _create_temp_view(self, table_name, source):
+        if table_name not in self._temp_views and table_name in self.list_tables():
+            raise ValueError(
+                f"{table_name} already exists as a non-temporary table or view"
+            )
+        src = sg.exp.Create(
+            this=sg.table(table_name),  # CREATE ... 'table_name'
+            kind="VIEW",  # VIEW
+            replace=True,  # OR REPLACE
+            expression=source,  # AS ...
+        )
+        self.raw_sql(src.sql(dialect=self.name, pretty=True))
+        self._temp_views.add(table_name)
+        self._register_temp_view_cleanup(table_name)
+
+    def _register_temp_view_cleanup(self, name: str) -> None:
+        def drop(self, name: str, query: str):
+            self.raw_sql(query)
+            self._temp_views.discard(name)
+
+        src = sg.exp.Drop(this=sg.table(name), kind="VIEW", exists=True)
+        query = src.sql(self.name, pretty=True)
+        atexit.register(drop, self, name=name, query=query)

ibis/backends/clickhouse/compiler/relations.py

@@ -231,3 +231,12 @@ def _dropna(op: ops.DropNa, *, table, how, subset, **_):
 def _sql_string_view(op: ops.SQLStringView, query: str, **_: Any):
     table = sg.table(op.name)
     return sg.select(STAR).from_(table).with_(table, as_=query, dialect="clickhouse")
+
+
+@translate_rel.register
+def _view(op: ops.View, *, child, name: str, **_):
+    # TODO: find a way to do this without creating a temporary view
+    backend = op.child.to_expr()._find_backend()
+    source = sg.select(STAR).from_(child)
+    backend._create_temp_view(table_name=name, source=source)
+    return sg.table(name)

ibis/backends/tests/test_dot_sql.py

@@ -14,9 +14,7 @@
 except ImportError:
     PolarsComputeError = None
 
-table_dot_sql_notimpl = pytest.mark.notimpl(
-    ["bigquery", "clickhouse", "impala", "druid"]
-)
+table_dot_sql_notimpl = pytest.mark.notimpl(["bigquery", "impala", "druid"])
 dot_sql_notimpl = pytest.mark.notimpl(["datafusion"])
 dot_sql_notyet = pytest.mark.notyet(
     ["snowflake", "oracle"],
@@ -151,11 +149,11 @@ def test_table_dot_sql_with_join(backend, con):
             """
             SELECT
                 l.fancy_af AS yas,
-                r.s
+                r.s AS s
             FROM awesome_t AS l
             LEFT JOIN ft AS r
             ON l.s = r.s
-            """
+            """  # clickhouse needs the r.s AS s, otherwise the column name is returned as r.s
         )
         .order_by(["s", "yas"])
     )
@@ -250,7 +248,6 @@ def test_dot_sql_reuse_alias_with_different_types(backend, alltypes, df):
         *no_sqlglot_dialect,
     ],
 )
-@pytest.mark.broken(["clickhouse"], raises=DatabaseError)
 @pytest.mark.notyet(["polars"], raises=PolarsComputeError)
 @table_dot_sql_notimpl
 @dot_sql_notimpl