fix(clickhouse): generate redundant aliases to workaround clickhouse …

…naming behavior

ibis/backends/clickhouse/compiler.py

@@ -2,7 +2,7 @@
 
 import calendar
 import math
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 import sqlglot as sg
 import sqlglot.expressions as sge
@@ -15,6 +15,9 @@
 from ibis.backends.sql.datatypes import ClickHouseType
 from ibis.backends.sql.dialects import ClickHouse
 
+if TYPE_CHECKING:
+    from collections.abc import Mapping
+
 
 class ClickhouseAggGen(AggGen):
     def aggregate(self, compiler, name, *args, where=None):
@@ -705,3 +708,29 @@ def visit_TableUnnest(
             )
 
         return select
+
+    def _cleanup_names(self, exprs: Mapping[str, sge.Expression]):
+        """Compose `_gen_valid_name` and `_dedup_name` to clean up names in projections.
+
+        ClickHouse has a bug where this fails semantic validation:
+
+        ```sql
+        SELECT
+          "o"."a"
+        FROM (
+          SELECT
+            "w"."a"
+          FROM "{name}" AS "s"
+          INNER JOIN "{name}" AS "w"
+          USING ("a")
+        ) AS "o"
+        ```
+
+        Adding a redundant aliasing operation here (`"w"."a" AS "a"`) helps
+        ClickHouse. Not entirely clear whether this is an upstream bug.
+        """
+        quoted = self.quoted
+        return (
+            value.as_(self._gen_valid_name(name), quoted=quoted, copy=False)
+            for name, value in exprs.items()
+        )

ibis/backends/clickhouse/tests/snapshots/test_functions/test_cast_double_col/float/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."double_col"
+  "t0"."double_col" AS "double_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/bigint_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."bigint_col"
+  "t0"."bigint_col" AS "bigint_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/bool_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."bool_col"
+  "t0"."bool_col" AS "bool_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/date_string_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."date_string_col"
+  "t0"."date_string_col" AS "date_string_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/double_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."double_col"
+  "t0"."double_col" AS "double_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/float_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."float_col"
+  "t0"."float_col" AS "float_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/id/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."id"
+  "t0"."id" AS "id"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/int_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."int_col"
+  "t0"."int_col" AS "int_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/month/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."month"
+  "t0"."month" AS "month"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/smallint_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."smallint_col"
+  "t0"."smallint_col" AS "smallint_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/string_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."string_col"
+  "t0"."string_col" AS "string_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/timestamp_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."timestamp_col"
+  "t0"."timestamp_col" AS "timestamp_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/tinyint_col/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."tinyint_col"
+  "t0"."tinyint_col" AS "tinyint_col"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_functions/test_noop_cast/year/out.sql

@@ -1,3 +1,3 @@
 SELECT
-  "t0"."year"
+  "t0"."year" AS "year"
 FROM "functional_alltypes" AS "t0"

ibis/backends/clickhouse/tests/snapshots/test_select/test_complex_array_expr_projection/out.sql

@@ -2,7 +2,7 @@ SELECT
   CAST("t1"."string_col" AS Nullable(Float64)) AS "Cast(string_col, float64)"
 FROM (
   SELECT
-    "t0"."string_col",
+    "t0"."string_col" AS "string_col",
     COUNT(*) AS "count"
   FROM "functional_alltypes" AS "t0"
   GROUP BY

ibis/backends/clickhouse/tests/snapshots/test_select/test_complex_join/out.sql

@@ -1,17 +1,17 @@
 SELECT
-  "t4"."a",
-  "t4"."b",
-  "t4"."c",
-  "t4"."d",
+  "t4"."a" AS "a",
+  "t4"."b" AS "b",
+  "t4"."c" AS "c",
+  "t4"."d" AS "d",
   "t4"."c" / (
     "t4"."a" - "t4"."b"
   ) AS "e"
 FROM (
   SELECT
-    "t2"."a",
-    "t2"."b",
-    "t3"."c",
-    "t3"."d"
+    "t2"."a" AS "a",
+    "t2"."b" AS "b",
+    "t3"."c" AS "c",
+    "t3"."d" AS "d"
   FROM "s" AS "t2"
   INNER JOIN "t" AS "t3"
     ON "t2"."a" = "t3"."c"

ibis/backends/clickhouse/tests/snapshots/test_select/test_count_name/out.sql

@@ -1,5 +1,5 @@
 SELECT
-  "t0"."a",
+  "t0"."a" AS "a",
   COALESCE(countIf(NOT (
     "t0"."b"
   )), 0) AS "A",

ibis/backends/clickhouse/tests/snapshots/test_select/test_join_self_reference/out.sql

@@ -1,17 +1,17 @@
 SELECT
-  "t1"."id",
-  "t1"."bool_col",
-  "t1"."tinyint_col",
-  "t1"."smallint_col",
-  "t1"."int_col",
-  "t1"."bigint_col",
-  "t1"."float_col",
-  "t1"."double_col",
-  "t1"."date_string_col",
-  "t1"."string_col",
-  "t1"."timestamp_col",
-  "t1"."year",
-  "t1"."month"
+  "t1"."id" AS "id",
+  "t1"."bool_col" AS "bool_col",
+  "t1"."tinyint_col" AS "tinyint_col",
+  "t1"."smallint_col" AS "smallint_col",
+  "t1"."int_col" AS "int_col",
+  "t1"."bigint_col" AS "bigint_col",
+  "t1"."float_col" AS "float_col",
+  "t1"."double_col" AS "double_col",
+  "t1"."date_string_col" AS "date_string_col",
+  "t1"."string_col" AS "string_col",
+  "t1"."timestamp_col" AS "timestamp_col",
+  "t1"."year" AS "year",
+  "t1"."month" AS "month"
 FROM "functional_alltypes" AS "t1"
 INNER JOIN "functional_alltypes" AS "t2"
   ON "t1"."id" = "t2"."id"

ibis/backends/clickhouse/tests/snapshots/test_select/test_named_from_filter_groupby/out1.sql

@@ -1,5 +1,5 @@
 SELECT
-  "t1"."key",
+  "t1"."key" AS "key",
   SUM((
     (
       "t1"."value" + 1

ibis/backends/clickhouse/tests/snapshots/test_select/test_named_from_filter_groupby/out2.sql

@@ -1,5 +1,5 @@
 SELECT
-  "t1"."key",
+  "t1"."key" AS "key",
   SUM((
     (
       "t1"."value" + 1

ibis/backends/clickhouse/tests/snapshots/test_select/test_simple_joins/playerID-awardID-any_inner_join/out.sql

@@ -1,26 +1,26 @@
 SELECT
-  "t2"."playerID",
-  "t2"."yearID",
-  "t2"."stint",
-  "t2"."teamID",
-  "t2"."lgID",
-  "t2"."G",
-  "t2"."AB",
-  "t2"."R",
-  "t2"."H",
-  "t2"."X2B",
-  "t2"."X3B",
-  "t2"."HR",
-  "t2"."RBI",
-  "t2"."SB",
-  "t2"."CS",
-  "t2"."BB",
-  "t2"."SO",
-  "t2"."IBB",
-  "t2"."HBP",
-  "t2"."SH",
-  "t2"."SF",
-  "t2"."GIDP"
+  "t2"."playerID" AS "playerID",
+  "t2"."yearID" AS "yearID",
+  "t2"."stint" AS "stint",
+  "t2"."teamID" AS "teamID",
+  "t2"."lgID" AS "lgID",
+  "t2"."G" AS "G",
+  "t2"."AB" AS "AB",
+  "t2"."R" AS "R",
+  "t2"."H" AS "H",
+  "t2"."X2B" AS "X2B",
+  "t2"."X3B" AS "X3B",
+  "t2"."HR" AS "HR",
+  "t2"."RBI" AS "RBI",
+  "t2"."SB" AS "SB",
+  "t2"."CS" AS "CS",
+  "t2"."BB" AS "BB",
+  "t2"."SO" AS "SO",
+  "t2"."IBB" AS "IBB",
+  "t2"."HBP" AS "HBP",
+  "t2"."SH" AS "SH",
+  "t2"."SF" AS "SF",
+  "t2"."GIDP" AS "GIDP"
 FROM "batting" AS "t2"
 ANY JOIN "awards_players" AS "t3"
   ON "t2"."playerID" = "t3"."awardID"

ibis/backends/clickhouse/tests/snapshots/test_select/test_simple_joins/playerID-awardID-any_left_join/out.sql

@@ -1,26 +1,26 @@
 SELECT
-  "t2"."playerID",
-  "t2"."yearID",
-  "t2"."stint",
-  "t2"."teamID",
-  "t2"."lgID",
-  "t2"."G",
-  "t2"."AB",
-  "t2"."R",
-  "t2"."H",
-  "t2"."X2B",
-  "t2"."X3B",
-  "t2"."HR",
-  "t2"."RBI",
-  "t2"."SB",
-  "t2"."CS",
-  "t2"."BB",
-  "t2"."SO",
-  "t2"."IBB",
-  "t2"."HBP",
-  "t2"."SH",
-  "t2"."SF",
-  "t2"."GIDP"
+  "t2"."playerID" AS "playerID",
+  "t2"."yearID" AS "yearID",
+  "t2"."stint" AS "stint",
+  "t2"."teamID" AS "teamID",
+  "t2"."lgID" AS "lgID",
+  "t2"."G" AS "G",
+  "t2"."AB" AS "AB",
+  "t2"."R" AS "R",
+  "t2"."H" AS "H",
+  "t2"."X2B" AS "X2B",
+  "t2"."X3B" AS "X3B",
+  "t2"."HR" AS "HR",
+  "t2"."RBI" AS "RBI",
+  "t2"."SB" AS "SB",
+  "t2"."CS" AS "CS",
+  "t2"."BB" AS "BB",
+  "t2"."SO" AS "SO",
+  "t2"."IBB" AS "IBB",
+  "t2"."HBP" AS "HBP",
+  "t2"."SH" AS "SH",
+  "t2"."SF" AS "SF",
+  "t2"."GIDP" AS "GIDP"
 FROM "batting" AS "t2"
 LEFT ANY JOIN "awards_players" AS "t3"
   ON "t2"."playerID" = "t3"."awardID"

ibis/backends/clickhouse/tests/snapshots/test_select/test_simple_joins/playerID-awardID-inner_join/out.sql

@@ -1,26 +1,26 @@
 SELECT
-  "t2"."playerID",
-  "t2"."yearID",
-  "t2"."stint",
-  "t2"."teamID",
-  "t2"."lgID",
-  "t2"."G",
-  "t2"."AB",
-  "t2"."R",
-  "t2"."H",
-  "t2"."X2B",
-  "t2"."X3B",
-  "t2"."HR",
-  "t2"."RBI",
-  "t2"."SB",
-  "t2"."CS",
-  "t2"."BB",
-  "t2"."SO",
-  "t2"."IBB",
-  "t2"."HBP",
-  "t2"."SH",
-  "t2"."SF",
-  "t2"."GIDP"
+  "t2"."playerID" AS "playerID",
+  "t2"."yearID" AS "yearID",
+  "t2"."stint" AS "stint",
+  "t2"."teamID" AS "teamID",
+  "t2"."lgID" AS "lgID",
+  "t2"."G" AS "G",
+  "t2"."AB" AS "AB",
+  "t2"."R" AS "R",
+  "t2"."H" AS "H",
+  "t2"."X2B" AS "X2B",
+  "t2"."X3B" AS "X3B",
+  "t2"."HR" AS "HR",
+  "t2"."RBI" AS "RBI",
+  "t2"."SB" AS "SB",
+  "t2"."CS" AS "CS",
+  "t2"."BB" AS "BB",
+  "t2"."SO" AS "SO",
+  "t2"."IBB" AS "IBB",
+  "t2"."HBP" AS "HBP",
+  "t2"."SH" AS "SH",
+  "t2"."SF" AS "SF",
+  "t2"."GIDP" AS "GIDP"
 FROM "batting" AS "t2"
 INNER JOIN "awards_players" AS "t3"
   ON "t2"."playerID" = "t3"."awardID"