Skip to content

fix(parser): parse IS/ISNULL/NOTNULL with lower precedence than comparison #8668

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
ansh-rohilla wants to merge 1 commit into from
+55 −15
Closed

fix(parser): parse IS/ISNULL/NOTNULL with lower precedence than comparison #8668

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 35 additions & 15 deletions sqlglot/parser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1208,7 +1208,7 @@ class Parser:

UNARY_PARSERS: t.ClassVar = {
TokenType.PLUS: lambda self: self._parse_unary(), # Unary + is handled as a no-op
TokenType.NOT: lambda self: self.expression(exp.Not(this=self._parse_equality())),
TokenType.NOT: lambda self: self.expression(exp.Not(this=self._parse_is_predicate())),
TokenType.TILDE: lambda self: self.expression(exp.BitwiseNot(this=self._parse_unary())),
TokenType.DASH: lambda self: self.expression(exp.Neg(this=self._parse_unary())),
TokenType.PIPE_SLASH: lambda self: self.expression(exp.Sqrt(this=self._parse_unary())),
Expand Down Expand Up @@ -1286,7 +1286,6 @@ class Parser:
TokenType.ILIKE: binary_range_parser(exp.ILike),
TokenType.IN: lambda self, this: self._parse_in(this),
TokenType.IRLIKE: binary_range_parser(exp.RegexpILike),
TokenType.IS: lambda self, this: self._parse_is(this),
TokenType.LIKE: binary_range_parser(exp.Like),
TokenType.LT_AT: binary_range_parser(exp.ArrayContainedBy),
TokenType.OVERLAPS: binary_range_parser(exp.Overlaps),
Expand Down Expand Up @@ -6177,17 +6176,48 @@ def _parse_disjunction(self) -> exp.Expr | None:
return this

def _parse_conjunction(self) -> exp.Expr | None:
this = self._parse_equality()
this = self._parse_is_predicate()
while self._match_set(self.CONJUNCTION):
comments = self._prev_comments
this = self.expression(
self.CONJUNCTION[self._prev.token_type](
this=this, expression=self._parse_equality()
this=this, expression=self._parse_is_predicate()
),
comments=comments,
)
return this

def _parse_is_predicate(self) -> exp.Expr | None:
this = self._parse_equality()
while True:
negate = self._match(TokenType.NOT)
if self._match(TokenType.IS):
expression = self._parse_is(this)
if not expression:
if negate:
self._retreat(self._index - 1)
return this

this = expression
if negate:
this = self.expression(exp.Not(this=this))
elif self._match(TokenType.ISNULL) or (negate and self._match(TokenType.NULL)):
this = self.expression(exp.Is(this=this, expression=exp.Null()))
this = self.expression(exp.Not(this=this)) if negate else this
elif self._match(TokenType.NOTNULL):
# Postgres supports ISNULL and NOTNULL for conditions.
# https://blog.andreiavram.ro/postgresql-null-composite-type/
if self.dialect.NORMALIZE_NOT_NULL:
this = self.expression(exp.Is(this=this, expression=exp.Null()))
this = self.expression(exp.Not(this=this))
else:
this = self.expression(exp.Is(this=this, expression=exp.Null(), negate=True))
else:
if negate:
self._retreat(self._index - 1)
break
return this

def _parse_equality(self) -> exp.Expr | None:
this = self._parse_comparison()
while self._match_set(self.EQUALITY):
Expand Down Expand Up @@ -6221,16 +6251,6 @@ def _parse_range(self, this: exp.Expr | None = None) -> exp.Expr | None:
return this

this = expression
elif self._match(TokenType.ISNULL) or (negate and self._match(TokenType.NULL)):
this = self.expression(exp.Is(this=this, expression=exp.Null()))
elif self._match(TokenType.NOTNULL):
# Postgres supports ISNULL and NOTNULL for conditions.
# https://blog.andreiavram.ro/postgresql-null-composite-type/
if self.dialect.NORMALIZE_NOT_NULL:
this = self.expression(exp.Is(this=this, expression=exp.Null()))
this = self.expression(exp.Not(this=this))
else:
this = self.expression(exp.Is(this=this, expression=exp.Null(), negate=True))
else:
if negate:
self._retreat(self._index - 1)
Expand All @@ -6239,7 +6259,7 @@ def _parse_range(self, this: exp.Expr | None = None) -> exp.Expr | None:
if negate:
this = self._negate_range(this)
if self._curr and (
self._curr.token_type == TokenType.NOT
self._curr.token_type in (TokenType.NOT, TokenType.IS)
or self._curr.token_type in self.RANGE_PARSERS
):
this = self.expression(exp.Paren(this=this))
Expand Down
5 changes: 5 additions & 0 deletions tests/dialects/test_postgres.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -79,6 +79,11 @@ def test_postgres(self):
self.validate_identity("SELECT DATE_TRUNC('DAY', x, 'America/New_York')")
self.validate_identity("STRING_TO_ARRAY('xx~^~yy~^~zz', '~^~', 'yy')")
self.validate_identity("SELECT x FROM t WHERE CAST($1 AS TEXT) = 'ok'")
self.validate_identity("SELECT * FROM t WHERE t.a = t.b IS NULL")
self.validate_identity("SELECT * FROM t WHERE t.a = (t.b IS NULL)")
self.validate_identity("SELECT * FROM t WHERE t.a = t.b IS NOT NULL")
self.validate_identity("SELECT * FROM t WHERE t.a = t.b IS TRUE")
self.validate_identity("SELECT * FROM t WHERE t.a = t.b IS FALSE")
self.validate_identity("SELECT * FROM t TABLESAMPLE SYSTEM (50) REPEATABLE (55)")
self.validate_identity("x @@ y")
self.validate_identity("doc @? '$.a[*] ? (@ > 2)'")
Expand Down
15 changes: 15 additions & 0 deletions tests/test_parser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -281,6 +281,21 @@ def test_mod_precedence(self):
self.assertEqual(expression.this.expression.sql(), "3")
self.assertEqual(expression.expression.sql(), "2")

def test_is_precedence(self):
expression = parse_one("SELECT 1 = 1 IS NULL").expressions[0]

self.assertIsInstance(expression, exp.Is)
self.assertIsInstance(expression.this, exp.EQ)
self.assertEqual(expression.this.this.sql(), "1")
self.assertEqual(expression.this.expression.sql(), "1")
self.assertIsInstance(expression.expression, exp.Null)

parenthesized = parse_one("SELECT 1 = (1 IS NULL)").expressions[0]
self.assertIsInstance(parenthesized, exp.EQ)
self.assertIsInstance(parenthesized.expression.this, exp.Is)

self.assertEqual(parse_one("SELECT 1 is").sql(), "SELECT 1 AS is")

def test_limit_percent_parses_without_modulo(self):
expression = parse_one("SELECT * FROM range(1000) LIMIT 1 / 10% OFFSET 5")
limit = expression.args["limit"]
Expand Down
Loading