feat(datafusion): pivot_longer

ibis/backends/sql/compilers/datafusion.py

@@ -478,3 +478,10 @@ def visit_Aggregate(self, op, *, parent, groups, metrics):
             sel = sel.group_by(*by_names_quoted)
 
         return sel
+
+    def visit_StructColumn(self, op, *, names, values):
+        args = []
+        for name, value in zip(names, values):
+            args.append(sge.convert(name))
+            args.append(value)
+        return self.f.named_struct(*args)

ibis/backends/tests/snapshots/test_sql/test_union_aliasing/datafusion/out.sql

@@ -0,0 +1,90 @@
+WITH "t5" AS (
+  SELECT
+    "t4"."field_of_study",
+    FIRST_VALUE("t4"."diff") FILTER(WHERE
+      NOT "t4"."diff" IS NULL) AS "diff"
+  FROM (
+    SELECT
+      "t4"."years",
+      "t4"."degrees",
+      "t4"."earliest_degrees",
+      "t4"."latest_degrees",
+      "t4"."diff",
+      "t4"."field_of_study"
+    FROM (
+      SELECT
+        "t3"."field_of_study",
+        "t3"."years",
+        "t3"."degrees",
+        "t3"."earliest_degrees",
+        "t3"."latest_degrees",
+        "t3"."latest_degrees" - "t3"."earliest_degrees" AS "diff"
+      FROM (
+        SELECT
+          "t2"."field_of_study",
+          "t2"."years",
+          "t2"."degrees",
+          FIRST_VALUE("t2"."degrees") OVER (PARTITION BY "t2"."field_of_study" ORDER BY "t2"."years" ASC ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS "earliest_degrees",
+          LAST_VALUE("t2"."degrees") OVER (PARTITION BY "t2"."field_of_study" ORDER BY "t2"."years" ASC ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS "latest_degrees"
+        FROM (
+          SELECT
+            "t1"."field_of_study",
+            "t1"."__pivoted__"."years" AS "years",
+            "t1"."__pivoted__"."degrees" AS "degrees"
+          FROM (
+            SELECT
+              "t0"."field_of_study",
+              UNNEST(
+                MAKE_ARRAY(
+                  NAMED_STRUCT('years', '1970-71', 'degrees', "t0"."1970-71"),
+                  NAMED_STRUCT('years', '1975-76', 'degrees', "t0"."1975-76"),
+                  NAMED_STRUCT('years', '1980-81', 'degrees', "t0"."1980-81"),
+                  NAMED_STRUCT('years', '1985-86', 'degrees', "t0"."1985-86"),
+                  NAMED_STRUCT('years', '1990-91', 'degrees', "t0"."1990-91"),
+                  NAMED_STRUCT('years', '1995-96', 'degrees', "t0"."1995-96"),
+                  NAMED_STRUCT('years', '2000-01', 'degrees', "t0"."2000-01"),
+                  NAMED_STRUCT('years', '2005-06', 'degrees', "t0"."2005-06"),
+                  NAMED_STRUCT('years', '2010-11', 'degrees', "t0"."2010-11"),
+                  NAMED_STRUCT('years', '2011-12', 'degrees', "t0"."2011-12"),
+                  NAMED_STRUCT('years', '2012-13', 'degrees', "t0"."2012-13"),
+                  NAMED_STRUCT('years', '2013-14', 'degrees', "t0"."2013-14"),
+                  NAMED_STRUCT('years', '2014-15', 'degrees', "t0"."2014-15"),
+                  NAMED_STRUCT('years', '2015-16', 'degrees', "t0"."2015-16"),
+                  NAMED_STRUCT('years', '2016-17', 'degrees', "t0"."2016-17"),
+                  NAMED_STRUCT('years', '2017-18', 'degrees', "t0"."2017-18"),
+                  NAMED_STRUCT('years', '2018-19', 'degrees', "t0"."2018-19"),
+                  NAMED_STRUCT('years', '2019-20', 'degrees', "t0"."2019-20")
+                )
+              ) AS "__pivoted__"
+            FROM "humanities" AS "t0"
+          ) AS "t1"
+        ) AS "t2"
+      ) AS "t3"
+    ) AS "t4"
+  ) AS t4
+  GROUP BY
+    "t4"."field_of_study"
+)
+SELECT
+  *
+FROM (
+  SELECT
+    *
+  FROM "t5" AS "t6"
+  ORDER BY
+    "t6"."diff" DESC NULLS LAST
+  LIMIT 10
+) AS "t9"
+UNION ALL
+SELECT
+  *
+FROM (
+  SELECT
+    *
+  FROM "t5" AS "t6"
+  WHERE
+    "t6"."diff" < 0
+  ORDER BY
+    "t6"."diff" ASC
+  LIMIT 10
+) AS "t10"

ibis/backends/tests/test_array.py

@@ -901,9 +901,7 @@ def test_zip_null(con, fn):
 @builtin_array
 @pytest.mark.notimpl(["postgres"], raises=PsycoPg2SyntaxError)
 @pytest.mark.notimpl(["risingwave"], raises=PsycoPg2ProgrammingError)
-@pytest.mark.notimpl(
-    ["datafusion"], raises=Exception, reason="probably generating invalid SQL"
-)
+@pytest.mark.notimpl(["datafusion"], raises=Exception, reason="not yet supported")
 @pytest.mark.notimpl(
     ["polars"],
     raises=com.OperationNotDefinedError,

ibis/backends/tests/test_generic.py

@@ -1403,7 +1403,7 @@ def query(t, group_cols):
 @pytest.mark.notimpl(["oracle", "exasol"], raises=com.OperationNotDefinedError)
 @pytest.mark.notimpl(["druid"], raises=AssertionError)
 @pytest.mark.notyet(
-    ["datafusion", "impala", "mssql", "mysql", "sqlite"],
+    ["impala", "mssql", "mysql", "sqlite"],
     reason="backend doesn't support arrays and we don't implement pivot_longer with unions yet",
     raises=com.OperationNotDefinedError,
 )

ibis/backends/tests/test_sql.py

@@ -102,7 +102,7 @@ def test_isin_bug(con, snapshot):
     raises=NotImplementedError,
 )
 @pytest.mark.notyet(
-    ["datafusion", "exasol", "oracle", "flink"],
+    ["exasol", "oracle", "flink"],
     reason="no unnest support",
     raises=exc.OperationNotDefinedError,
 )