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feat: parse Snowflake directed joins #26

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Merged
osipovartem merged 1 commit into from
Sep 13, 2026
Merged

feat: parse Snowflake directed joins #26

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19 changes: 11 additions & 8 deletions src/ast/query.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2655,6 +2655,8 @@ pub struct Join {
/// ClickHouse supports the optional `GLOBAL` keyword before the join operator.
/// See [ClickHouse](https://clickhouse.com/docs/en/sql-reference/statements/select/join)
pub global: bool,
/// Snowflake `DIRECTED` join-order directive.
pub directed: bool,
/// The join operator and its constraint (INNER/LEFT/RIGHT/CROSS/ASOF/etc.).
pub join_operator: JoinOperator,
}
Expand Down Expand Up @@ -2685,52 +2687,53 @@ impl fmt::Display for Join {
if self.global {
write!(f, "GLOBAL ")?;
}
let directed = if self.directed { "DIRECTED " } else { "" };

match &self.join_operator {
JoinOperator::Join(constraint) => f.write_fmt(format_args!(
"{}JOIN {}{}",
"{}{directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::Inner(constraint) => f.write_fmt(format_args!(
"{}INNER JOIN {}{}",
"{}INNER {directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::Left(constraint) => f.write_fmt(format_args!(
"{}LEFT JOIN {}{}",
"{}LEFT {directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::LeftOuter(constraint) => f.write_fmt(format_args!(
"{}LEFT OUTER JOIN {}{}",
"{}LEFT OUTER {directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::Right(constraint) => f.write_fmt(format_args!(
"{}RIGHT JOIN {}{}",
"{}RIGHT {directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::RightOuter(constraint) => f.write_fmt(format_args!(
"{}RIGHT OUTER JOIN {}{}",
"{}RIGHT OUTER {directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::FullOuter(constraint) => f.write_fmt(format_args!(
"{}FULL JOIN {}{}",
"{}FULL {directed}JOIN {}{}",
prefix(constraint),
self.relation,
suffix(constraint)
)),
JoinOperator::CrossJoin(constraint) => f.write_fmt(format_args!(
"CROSS JOIN {}{}",
"CROSS {directed}JOIN {}{}",
self.relation,
suffix(constraint)
)),
Expand Down
3 changes: 2 additions & 1 deletion src/ast/spans.rs
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Expand Up @@ -2220,7 +2220,8 @@ impl Spanned for Join {
fn span(&self) -> Span {
let Join {
relation,
global: _, // bool
global: _, // bool
directed: _, // bool
join_operator,
} = self;

Expand Down
5 changes: 5 additions & 0 deletions src/dialect/mod.rs
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Expand Up @@ -433,6 +433,11 @@ pub trait Dialect: Debug + Any {
false
}

/// Returns true if the dialect supports Snowflake-style `DIRECTED` joins.
fn supports_directed_join(&self) -> bool {
false
}

/// Returns true if the dialect supports CONNECT BY.
fn supports_connect_by(&self) -> bool {
false
Expand Down
6 changes: 6 additions & 0 deletions src/dialect/snowflake.rs
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Expand Up @@ -483,6 +483,10 @@ impl Dialect for SnowflakeDialect {
false
}

fn supports_directed_join(&self) -> bool {
true
}

fn is_reserved_for_identifier(&self, kw: Keyword) -> bool {
// Unreserve some keywords that Snowflake accepts as identifiers
// See: https://docs.snowflake.com/en/sql-reference/reserved-keywords
Expand Down Expand Up @@ -589,6 +593,8 @@ impl Dialect for SnowflakeDialect {

Keyword::GLOBAL if parser.peek_keyword(Keyword::FULL) => false,

Keyword::DIRECTED if parser.peek_keyword(Keyword::JOIN) => false,

// Reserved keywords by the Snowflake dialect, which seem to be less strictive
// than what is listed in `keywords::RESERVED_FOR_TABLE_ALIAS`. The following
// keywords were tested with the this statement: `SELECT <KW>.* FROM tbl <KW>`.
Expand Down
1 change: 1 addition & 0 deletions src/keywords.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -336,6 +336,7 @@ define_keywords!(
DETAIL,
DETERMINISTIC,
DIMENSIONS,
DIRECTED,
DIRECTORY,
DISABLE,
DISCARD,
Expand Down
32 changes: 30 additions & 2 deletions src/parser/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -15784,9 +15784,11 @@ impl<'a> Parser<'a> {
loop {
let global = self.parse_keyword(Keyword::GLOBAL);
let join = if self.parse_keyword(Keyword::CROSS) {
let directed =
self.dialect.supports_directed_join() && self.parse_keyword(Keyword::DIRECTED);
let join_operator = if self.parse_keyword(Keyword::JOIN) {
JoinOperator::CrossJoin(JoinConstraint::None)
} else if self.parse_keyword(Keyword::APPLY) {
} else if !directed && self.parse_keyword(Keyword::APPLY) {
// MSSQL extension, similar to CROSS JOIN LATERAL
JoinOperator::CrossApply
} else {
Expand All @@ -15804,6 +15806,7 @@ impl<'a> Parser<'a> {
Join {
relation,
global,
directed,
join_operator,
}
} else if self.parse_keyword(Keyword::OUTER) {
Expand All @@ -15812,6 +15815,7 @@ impl<'a> Parser<'a> {
Join {
relation: self.parse_table_factor()?,
global,
directed: false,
join_operator: JoinOperator::OuterApply,
}
} else if self.parse_keyword(Keyword::ASOF) {
Expand All @@ -15822,6 +15826,7 @@ impl<'a> Parser<'a> {
Join {
relation,
global,
directed: false,
join_operator: JoinOperator::AsOf {
match_condition,
constraint: self.parse_join_constraint(false)?,
Expand All @@ -15834,6 +15839,7 @@ impl<'a> Parser<'a> {
Join {
relation: self.parse_table_factor()?,
global,
directed: false,
join_operator: JoinOperator::InnerArrayJoin,
}
} else if self.dialect.supports_array_join_syntax()
Expand All @@ -15843,6 +15849,7 @@ impl<'a> Parser<'a> {
Join {
relation: self.parse_table_factor()?,
global,
directed: false,
join_operator: JoinOperator::LeftArrayJoin,
}
} else if self.dialect.supports_array_join_syntax()
Expand All @@ -15852,10 +15859,12 @@ impl<'a> Parser<'a> {
Join {
relation: self.parse_table_factor()?,
global,
directed: false,
join_operator: JoinOperator::ArrayJoin,
}
} else {
let natural = self.parse_keyword(Keyword::NATURAL);
let mut directed = false;
let peek_keyword = if let Token::Word(w) = &self.peek_token_ref().token {
w.keyword
} else {
Expand All @@ -15865,6 +15874,10 @@ impl<'a> Parser<'a> {
let join_operator_type = match peek_keyword {
Keyword::INNER | Keyword::JOIN => {
let inner = self.parse_keyword(Keyword::INNER); // [ INNER ]
if inner {
directed = self.dialect.supports_directed_join()
&& self.parse_keyword(Keyword::DIRECTED);
}
self.expect_keyword_is(Keyword::JOIN)?;
if inner {
JoinOperator::Inner
Expand All @@ -15879,10 +15892,13 @@ impl<'a> Parser<'a> {
Keyword::OUTER,
Keyword::SEMI,
Keyword::ANTI,
Keyword::DIRECTED,
Keyword::JOIN,
]);
match join_type {
Some(Keyword::OUTER) => {
directed = self.dialect.supports_directed_join()
&& self.parse_keyword(Keyword::DIRECTED);
self.expect_keyword_is(Keyword::JOIN)?;
if is_left {
JoinOperator::LeftOuter
Expand All @@ -15906,6 +15922,15 @@ impl<'a> Parser<'a> {
JoinOperator::RightAnti
}
}
Some(Keyword::DIRECTED) if self.dialect.supports_directed_join() => {
directed = true;
self.expect_keyword_is(Keyword::JOIN)?;
if is_left {
JoinOperator::Left
} else {
JoinOperator::Right
}
}
Some(Keyword::JOIN) => {
if is_left {
JoinOperator::Left
Expand All @@ -15915,7 +15940,7 @@ impl<'a> Parser<'a> {
}
_ => {
return Err(ParserError::ParserError(format!(
"expected OUTER, SEMI, ANTI or JOIN after {kw:?}"
"expected OUTER, SEMI, ANTI, DIRECTED or JOIN after {kw:?}"
)))
}
}
Expand All @@ -15933,6 +15958,8 @@ impl<'a> Parser<'a> {
Keyword::FULL => {
let _ = self.next_token(); // consume FULL
let _ = self.parse_keyword(Keyword::OUTER); // [ OUTER ]
directed = self.dialect.supports_directed_join()
&& self.parse_keyword(Keyword::DIRECTED);
self.expect_keyword_is(Keyword::JOIN)?;
JoinOperator::FullOuter
}
Expand Down Expand Up @@ -15967,6 +15994,7 @@ impl<'a> Parser<'a> {
Join {
relation,
global,
directed,
join_operator: join_operator_type(join_constraint),
}
};
Expand Down
1 change: 1 addition & 0 deletions src/test_utils.rs
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Expand Up @@ -432,6 +432,7 @@ pub fn join(relation: TableFactor) -> Join {
Join {
relation,
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::Natural),
}
}
Expand Down
1 change: 1 addition & 0 deletions tests/sqlparser_bigquery.rs
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Expand Up @@ -1786,6 +1786,7 @@ fn parse_join_constraint_unnest_alias() {
with_ordinality: false,
},
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::On(Expr::BinaryOp {
left: Box::new(Expr::Identifier("c1".into())),
op: BinaryOperator::Eq,
Expand Down
9 changes: 9 additions & 0 deletions tests/sqlparser_common.rs
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Expand Up @@ -7326,6 +7326,7 @@ fn parse_implicit_join() {
joins: vec![Join {
relation: table_from_name(ObjectName::from(vec!["t1b".into()])),
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::Natural),
}],
},
Expand All @@ -7334,6 +7335,7 @@ fn parse_implicit_join() {
joins: vec![Join {
relation: table_from_name(ObjectName::from(vec!["t2b".into()])),
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::Natural),
}],
},
Expand All @@ -7350,6 +7352,7 @@ fn parse_cross_join() {
Join {
relation: table_from_name(ObjectName::from(vec![Ident::new("t2")])),
global: false,
directed: false,
join_operator: JoinOperator::CrossJoin(JoinConstraint::None),
},
only(only(select.from).joins),
Expand All @@ -7362,6 +7365,7 @@ fn parse_cross_join_constraint() {
Join {
relation: table_from_name(ObjectName::from(vec![Ident::new("t2")])),
global: false,
directed: false,
join_operator: JoinOperator::CrossJoin(constraint),
}
}
Expand Down Expand Up @@ -7411,6 +7415,7 @@ fn parse_joins_on() {
index_hints: vec![],
},
global,
directed: false,
join_operator: f(JoinConstraint::On(Expr::BinaryOp {
left: Box::new(Expr::Identifier("c1".into())),
op: BinaryOperator::Eq,
Expand Down Expand Up @@ -7553,6 +7558,7 @@ fn parse_joins_using() {
index_hints: vec![],
},
global: false,
directed: false,
join_operator: f(JoinConstraint::Using(vec![ObjectName::from(vec![
"c1".into()
])])),
Expand Down Expand Up @@ -7648,6 +7654,7 @@ fn parse_natural_join() {
index_hints: vec![],
},
global: false,
directed: false,
join_operator: f(JoinConstraint::Natural),
}
}
Expand Down Expand Up @@ -7953,6 +7960,7 @@ fn parse_derived_tables() {
joins: vec![Join {
relation: table_from_name(ObjectName::from(vec!["t2".into()])),
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::Natural),
}],
}),
Expand Down Expand Up @@ -9055,6 +9063,7 @@ fn lateral_function() {
alias: None,
},
global: false,
directed: false,
join_operator: JoinOperator::Left(JoinConstraint::None),
}],
}],
Expand Down
5 changes: 5 additions & 0 deletions tests/sqlparser_mssql.rs
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Expand Up @@ -522,6 +522,7 @@ fn parse_mssql_openjson() {
alias: table_alias(true, "B")
},
global: false,
directed: false,
join_operator: JoinOperator::CrossApply
}]
}],
Expand Down Expand Up @@ -576,6 +577,7 @@ fn parse_mssql_openjson() {
alias: table_alias(true, "B")
},
global: false,
directed: false,
join_operator: JoinOperator::CrossApply
}]
}],
Expand Down Expand Up @@ -630,6 +632,7 @@ fn parse_mssql_openjson() {
alias: table_alias(true, "B")
},
global: false,
directed: false,
join_operator: JoinOperator::CrossApply
}]
}],
Expand Down Expand Up @@ -664,6 +667,7 @@ fn parse_mssql_openjson() {
alias: table_alias(true, "B")
},
global: false,
directed: false,
join_operator: JoinOperator::CrossApply
}]
}],
Expand Down Expand Up @@ -698,6 +702,7 @@ fn parse_mssql_openjson() {
alias: table_alias(true, "B")
},
global: false,
directed: false,
join_operator: JoinOperator::CrossApply
}]
}],
Expand Down
1 change: 1 addition & 0 deletions tests/sqlparser_mysql.rs
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Expand Up @@ -2756,6 +2756,7 @@ fn parse_update_with_joins() {
index_hints: vec![],
},
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::On(Expr::BinaryOp {
left: Box::new(Expr::CompoundIdentifier(vec![
Ident::new("o"),
Expand Down
1 change: 1 addition & 0 deletions tests/sqlparser_postgres.rs
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Expand Up @@ -5712,6 +5712,7 @@ fn parse_join_constraint_unnest_alias() {
with_ordinality: false,
},
global: false,
directed: false,
join_operator: JoinOperator::Join(JoinConstraint::On(Expr::BinaryOp {
left: Box::new(Expr::Identifier("c1".into())),
op: BinaryOperator::Eq,
Expand Down
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