Fixes #3962

fix some comment

sqlglot/dialects/starrocks.py

@@ -36,12 +36,9 @@ def _parse_unnest(self, with_alias: bool = True) -> t.Optional[exp.Unnest]:
  alias = unnest.args.get("alias")
 
  if not alias:
- # Starrocks defaults to naming the table alias as "unnest"
- alias = exp.TableAlias(
- this=exp.to_identifier("unnest"), columns=[exp.to_identifier("unnest")]
- )
+ alias = exp.TableAlias(columns=[exp.to_identifier("unnest")])
  unnest.set("alias", alias)
- if alias and not alias.args.get("columns"):
+ if not alias.args.get("columns"):
  # Starrocks defaults to naming the UNNEST column as "unnest"
  # if it's not otherwise specified
  alias.set("columns", [exp.to_identifier("unnest")])

sqlglot/expressions.py

@@ -5333,9 +5333,7 @@ class Explode(Func):
 
 # https://spark.apache.org/docs/latest/api/sql/#inline
 class Inline(Func):
- arg_types = {"this": True, "expressions": False}
- is_var_len_args = True
-
+ pass
 
 class ExplodeOuter(Explode):
  pass

sqlglot/transforms.py

@@ -3,7 +3,6 @@
 import typing as t
 
 from sqlglot import expressions as exp
-from sqlglot.expressions import Func
 from sqlglot.helper import find_new_name, name_sequence
 
 if t.TYPE_CHECKING:
@@ -303,17 +302,35 @@ def unnest_to_explode(
  support_unnest_func: bool = False,
 ) -> exp.Expression:
  """Convert cross join unnest into lateral view explode."""
+
+ def handle_unnest(u: exp.Unnest, _has_multi_expr: bool) -> None:
+ if unnest_using_arrays_zip and _has_multi_expr:
+ # Use INLINE(ARRAYS_ZIP(...)) for multiple expressions
+ u.set(
+ "expressions",
+ [exp.Anonymous(this="ARRAYS_ZIP", expressions=u.expressions)],
+ )
+
+ def udtf_type(u: exp.Unnest, _has_multi_expr: bool):
+ return (
+ exp.Posexplode
+ if u.args.get("offset")
+ else (exp.Inline if unnest_using_arrays_zip and _has_multi_expr else exp.Explode)
+ )
+
  if isinstance(expression, exp.Select):
  from_ = expression.args.get("from")
 
  if not support_unnest_func and from_ and isinstance(from_.this, exp.Unnest):
  unnest = from_.this
  alias = unnest.args.get("alias")
- udtf = exp.Posexplode if unnest.args.get("offset") else exp.Explode
+ has_multi_expr = len(unnest.expressions) > 1
+ handle_unnest(unnest, has_multi_expr)
  this, *expressions = unnest.expressions
+
  unnest.replace(
  exp.Table(
- this=udtf(
+ this=udtf_type(unnest, has_multi_expr)(
  this=this,
  expressions=expressions,
  ),
@@ -329,26 +346,22 @@ def unnest_to_explode(
  unnest = join_expr.this if is_lateral else join_expr
 
  if isinstance(unnest, exp.Unnest):
- alias = join_expr.args.get("alias") if is_lateral else unnest.args.get("alias")
+ alias = (
+ join_expr.args.get("alias")
+ if is_lateral and join_expr.args.get("alias")
+ else unnest.args.get("alias")
+ )
+ # The number of unnest.expressions will be changed by handle_unnest, we need to record it here
  has_multi_expr = len(unnest.expressions) > 1
- _udtf: type[Func] = exp.Posexplode if unnest.args.get("offset") else exp.Explode
+ handle_unnest(unnest, has_multi_expr)
 
  expression.args["joins"].remove(join)
 
- if unnest_using_arrays_zip and has_multi_expr:
- # Modify the logic to use arrays_zip if there are multiple expressions
- # Build arrays_zip with nested expressions correctly
- unnest.set(
- "expressions",
- [exp.Anonymous(this="ARRAYS_ZIP", expressions=unnest.expressions)],
- )
- _udtf = exp.Inline
-
  for e, column in zip(unnest.expressions, alias.columns if alias else []):
  expression.append(
  "laterals",
  exp.Lateral(
- this=_udtf(this=e),
+ this=udtf_type(unnest, has_multi_expr)(this=e),
  view=True,
  alias=exp.TableAlias(
  this=alias.this, # type: ignore

tests/dialects/test_starrocks.py

@@ -35,15 +35,17 @@ def test_unnest(self):
  "SELECT student, score, t.unnest FROM tests CROSS JOIN LATERAL UNNEST(scores) AS t",
  "SELECT student, score, t.unnest FROM tests CROSS JOIN LATERAL UNNEST(scores) AS t(unnest)",
  )
- self.validate_identity(
+ self.validate_all(
  "SELECT student, score, unnest FROM tests CROSS JOIN LATERAL UNNEST(scores)",
- "SELECT student, score, unnest FROM tests CROSS JOIN LATERAL UNNEST(scores) AS unnest(unnest)",
+ write={
+ "spark": "SELECT student, score, unnest FROM tests LATERAL VIEW EXPLODE(scores) AS unnest",
+ },
  )
  self.validate_all(
  r"""SELECT * FROM UNNEST(array['John','Jane','Jim','Jamie'], array[24,25,26,27]) AS t(name, age)""",
  write={
  "postgres": "SELECT * FROM UNNEST(ARRAY['John', 'Jane', 'Jim', 'Jamie'], ARRAY[24, 25, 26, 27]) AS t(name, age)",
- "spark": "SELECT * FROM EXPLODE(ARRAY('John', 'Jane', 'Jim', 'Jamie'), ARRAY(24, 25, 26, 27)) AS t(name, age)",
+ "spark": "SELECT * FROM INLINE(ARRAYS_ZIP(ARRAY('John', 'Jane', 'Jim', 'Jamie'), ARRAY(24, 25, 26, 27))) AS t(name, age)",
  },
  )
  # Use UNNEST to convert into multiple columns
@@ -59,9 +61,9 @@ def test_unnest(self):
  },
  )
  self.validate_all(
- r"""SELECT id, t.type, t.scores FROM example_table CROSS JOIN LATERAL unnest(split(type, ";"), scores) AS t(type,scores)""",
+ r"""SELECT id, t.type, t.scores FROM example_table_2 CROSS JOIN LATERAL unnest(split(type, ";"), scores) AS t(type,scores)""",
  write={
- "spark": r"""SELECT id, t.type, t.scores FROM example_table LATERAL VIEW INLINE(ARRAYS_ZIP(SPLIT(type, CONCAT('\\Q', ';')), scores)) t AS type, scores""",
+ "spark": r"""SELECT id, t.type, t.scores FROM example_table_2 LATERAL VIEW INLINE(ARRAYS_ZIP(SPLIT(type, CONCAT('\\Q', ';')), scores)) t AS type, scores""",
  },
  )