[sql 169/208] test(joins): add test for ibis-project#7288.

ibis/backends/tests/snapshots/test_join/test_complex_join_agg/out.sql

@@ -0,0 +1,17 @@
+SELECT
+  t3.key1 AS key1,
+  AVG(t3.value1 - t3.value2) AS avg_diff
+FROM (
+  SELECT
+    t0.value1 AS value1,
+    t0.key1 AS key1,
+    t0.key2 AS key2,
+    t1.value2 AS value2,
+    t1.key1 AS key1_right,
+    t1.key4 AS key4
+  FROM table1 AS t0
+  LEFT OUTER JOIN table2 AS t1
+    ON t0.key1 = t1.key1
+) AS t3
+GROUP BY
+  1

ibis/backends/tests/test_join.py

@@ -408,3 +408,13 @@ def test_outer_join_nullability(backend, how, nrows, gen_right, keys):
 
     result = expr.to_pyarrow()
     assert len(result) == nrows
+
+
+def test_complex_join_agg(snapshot):
+    t1 = ibis.table(dict(value1="float", key1="string", key2="string"), name="table1")
+    t2 = ibis.table(dict(value2="float", key1="string", key4="string"), name="table2")
+
+    avg_diff = (t1.value1 - t2.value2).mean()
+    expr = t1.left_join(t2, "key1").group_by(t1.key1).aggregate(avg_diff=avg_diff)
+
+    snapshot.assert_match(str(ibis.to_sql(expr, dialect="duckdb")), "out.sql")