feat: add DuckDB dialect (#878)

* feat: add DuckDB dialect

* formatting

* fix conflict

* support // in GenericDialect

* add DucDbDialect to all_dialects

* add comment from suggestion

Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>

* fix: support // in GenericDialect

---------

Co-authored-by: Andrew Lamb <andrew@nerdnetworks.org>

examples/cli.rs

@@ -46,6 +46,7 @@ $ cargo run --feature json_example --example cli FILENAME.sql [--dialectname]
         "--hive" => Box::new(HiveDialect {}),
         "--redshift" => Box::new(RedshiftSqlDialect {}),
         "--clickhouse" => Box::new(ClickHouseDialect {}),
+        "--duckdb" => Box::new(DuckDbDialect {}),
         "--generic" | "" => Box::new(GenericDialect {}),
         s => panic!("Unexpected parameter: {s}"),
     };

src/ast/operator.rs

@@ -85,6 +85,8 @@ pub enum BinaryOperator {
     BitwiseOr,
     BitwiseAnd,
     BitwiseXor,
+    /// Integer division operator `//` in DuckDB
+    DuckIntegerDivide,
     /// MySQL [`DIV`](https://dev.mysql.com/doc/refman/8.0/en/arithmetic-functions.html) integer division
     MyIntegerDivide,
     /// Support for custom operators (built by parsers outside this crate)
@@ -126,6 +128,7 @@ impl fmt::Display for BinaryOperator {
             BinaryOperator::BitwiseOr => f.write_str("|"),
             BinaryOperator::BitwiseAnd => f.write_str("&"),
             BinaryOperator::BitwiseXor => f.write_str("^"),
+            BinaryOperator::DuckIntegerDivide => f.write_str("//"),
             BinaryOperator::MyIntegerDivide => f.write_str("DIV"),
             BinaryOperator::Custom(s) => f.write_str(s),
             BinaryOperator::PGBitwiseXor => f.write_str("#"),

src/dialect/duckdb.rs

@@ -0,0 +1,31 @@
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use crate::dialect::Dialect;
+
+#[derive(Debug, Default)]
+pub struct DuckDbDialect;
+
+// In most cases the redshift dialect is identical to [`PostgresSqlDialect`].
+impl Dialect for DuckDbDialect {
+    fn is_identifier_start(&self, ch: char) -> bool {
+        ch.is_alphabetic() || ch == '_'
+    }
+
+    fn is_identifier_part(&self, ch: char) -> bool {
+        ch.is_alphabetic() || ch.is_ascii_digit() || ch == '$' || ch == '_'
+    }
+
+    fn supports_filter_during_aggregation(&self) -> bool {
+        true
+    }
+}

src/dialect/mod.rs

@@ -13,6 +13,7 @@
 mod ansi;
 mod bigquery;
 mod clickhouse;
+mod duckdb;
 mod generic;
 mod hive;
 mod mssql;
@@ -31,6 +32,7 @@ use core::str::Chars;
 pub use self::ansi::AnsiDialect;
 pub use self::bigquery::BigQueryDialect;
 pub use self::clickhouse::ClickHouseDialect;
+pub use self::duckdb::DuckDbDialect;
 pub use self::generic::GenericDialect;
 pub use self::hive::HiveDialect;
 pub use self::mssql::MsSqlDialect;
@@ -163,6 +165,7 @@ pub fn dialect_from_str(dialect_name: impl AsRef<str>) -> Option<Box<dyn Dialect
         "clickhouse" => Some(Box::new(ClickHouseDialect {})),
         "bigquery" => Some(Box::new(BigQueryDialect)),
         "ansi" => Some(Box::new(AnsiDialect {})),
+        "duckdb" => Some(Box::new(DuckDbDialect {})),
         _ => None,
     }
 }
@@ -214,6 +217,8 @@ mod tests {
         assert!(parse_dialect("BigQuery").is::<BigQueryDialect>());
         assert!(parse_dialect("ansi").is::<AnsiDialect>());
         assert!(parse_dialect("ANSI").is::<AnsiDialect>());
+        assert!(parse_dialect("duckdb").is::<DuckDbDialect>());
+        assert!(parse_dialect("DuckDb").is::<DuckDbDialect>());
 
         // error cases
         assert!(dialect_from_str("Unknown").is_none());

src/parser.rs

@@ -992,7 +992,7 @@ impl<'a> Parser<'a> {
     /// parse a group by expr. a group by expr can be one of group sets, roll up, cube, or simple
     /// expr.
     fn parse_group_by_expr(&mut self) -> Result<Expr, ParserError> {
-        if dialect_of!(self is PostgreSqlDialect | GenericDialect) {
+        if dialect_of!(self is PostgreSqlDialect | DuckDbDialect | GenericDialect) {
             if self.parse_keywords(&[Keyword::GROUPING, Keyword::SETS]) {
                 self.expect_token(&Token::LParen)?;
                 let result = self.parse_comma_separated(|p| p.parse_tuple(false, true))?;
@@ -1662,10 +1662,13 @@ impl<'a> Parser<'a> {
             }
             Token::Ampersand => Some(BinaryOperator::BitwiseAnd),
             Token::Div => Some(BinaryOperator::Divide),
-            Token::ShiftLeft if dialect_of!(self is PostgreSqlDialect | GenericDialect) => {
+            Token::DuckIntDiv if dialect_of!(self is DuckDbDialect | GenericDialect) => {
+                Some(BinaryOperator::DuckIntegerDivide)
+            }
+            Token::ShiftLeft if dialect_of!(self is PostgreSqlDialect | DuckDbDialect | GenericDialect) => {
                 Some(BinaryOperator::PGBitwiseShiftLeft)
             }
-            Token::ShiftRight if dialect_of!(self is PostgreSqlDialect | GenericDialect) => {
+            Token::ShiftRight if dialect_of!(self is PostgreSqlDialect | DuckDbDialect | GenericDialect) => {
                 Some(BinaryOperator::PGBitwiseShiftRight)
             }
             Token::Sharp if dialect_of!(self is PostgreSqlDialect) => {
@@ -2051,7 +2054,9 @@ impl<'a> Parser<'a> {
             Token::Caret | Token::Sharp | Token::ShiftRight | Token::ShiftLeft => Ok(22),
             Token::Ampersand => Ok(23),
             Token::Plus | Token::Minus => Ok(Self::PLUS_MINUS_PREC),
-            Token::Mul | Token::Div | Token::Mod | Token::StringConcat => Ok(40),
+            Token::Mul | Token::Div | Token::DuckIntDiv | Token::Mod | Token::StringConcat => {
+                Ok(40)
+            }
             Token::DoubleColon => Ok(50),
             Token::Colon => Ok(50),
             Token::ExclamationMark => Ok(50),
@@ -3842,7 +3847,7 @@ impl<'a> Parser<'a> {
                         } else {
                             let column_keyword = self.parse_keyword(Keyword::COLUMN);
 
-                            let if_not_exists = if dialect_of!(self is PostgreSqlDialect | BigQueryDialect | GenericDialect)
+                            let if_not_exists = if dialect_of!(self is PostgreSqlDialect | BigQueryDialect | DuckDbDialect | GenericDialect)
                             {
                                 self.parse_keywords(&[Keyword::IF, Keyword::NOT, Keyword::EXISTS])
                                     || if_not_exists
@@ -6315,7 +6320,7 @@ impl<'a> Parser<'a> {
         self.expect_keyword(Keyword::SET)?;
         let assignments = self.parse_comma_separated(Parser::parse_assignment)?;
         let from = if self.parse_keyword(Keyword::FROM)
-            && dialect_of!(self is GenericDialect | PostgreSqlDialect | BigQueryDialect | SnowflakeDialect | RedshiftSqlDialect | MsSqlDialect)
+            && dialect_of!(self is GenericDialect | PostgreSqlDialect | DuckDbDialect | BigQueryDialect | SnowflakeDialect | RedshiftSqlDialect | MsSqlDialect)
         {
             Some(self.parse_table_and_joins()?)
         } else {
@@ -6415,7 +6420,8 @@ impl<'a> Parser<'a> {
     pub fn parse_wildcard_additional_options(
         &mut self,
     ) -> Result<WildcardAdditionalOptions, ParserError> {
-        let opt_exclude = if dialect_of!(self is GenericDialect | SnowflakeDialect) {
+        let opt_exclude = if dialect_of!(self is GenericDialect | DuckDbDialect | SnowflakeDialect)
+        {
             self.parse_optional_select_item_exclude()?
         } else {
             None

src/test_utils.rs

@@ -168,6 +168,7 @@ pub fn all_dialects() -> TestedDialects {
             Box::new(MySqlDialect {}),
             Box::new(BigQueryDialect {}),
             Box::new(SQLiteDialect {}),
+            Box::new(DuckDbDialect {}),
         ],
         options: None,
     }

src/tokenizer.rs

@@ -35,7 +35,7 @@ use serde::{Deserialize, Serialize};
 use sqlparser_derive::{Visit, VisitMut};
 
 use crate::ast::DollarQuotedString;
-use crate::dialect::{BigQueryDialect, GenericDialect, SnowflakeDialect};
+use crate::dialect::{BigQueryDialect, DuckDbDialect, GenericDialect, SnowflakeDialect};
 use crate::dialect::{Dialect, MySqlDialect};
 use crate::keywords::{Keyword, ALL_KEYWORDS, ALL_KEYWORDS_INDEX};
 
@@ -98,6 +98,8 @@ pub enum Token {
     Mul,
     /// Division operator `/`
     Div,
+    /// Integer division operator `//` in DuckDB
+    DuckIntDiv,
     /// Modulo Operator `%`
     Mod,
     /// String concatenation `||`
@@ -212,6 +214,7 @@ impl fmt::Display for Token {
             Token::Minus => f.write_str("-"),
             Token::Mul => f.write_str("*"),
             Token::Div => f.write_str("/"),
+            Token::DuckIntDiv => f.write_str("//"),
             Token::StringConcat => f.write_str("||"),
             Token::Mod => f.write_str("%"),
             Token::LParen => f.write_str("("),
@@ -768,6 +771,9 @@ impl<'a> Tokenizer<'a> {
                                 comment,
                             })))
                         }
+                        Some('/') if dialect_of!(self is DuckDbDialect | GenericDialect) => {
+                            self.consume_and_return(chars, Token::DuckIntDiv)
+                        }
                         // a regular '/' operator
                         _ => Ok(Some(Token::Div)),
                     }

tests/sqlparser_common.rs

@@ -24,8 +24,9 @@ use sqlparser::ast::SelectItem::UnnamedExpr;
 use sqlparser::ast::TableFactor::Pivot;
 use sqlparser::ast::*;
 use sqlparser::dialect::{
-    AnsiDialect, BigQueryDialect, ClickHouseDialect, GenericDialect, HiveDialect, MsSqlDialect,
-    MySqlDialect, PostgreSqlDialect, RedshiftSqlDialect, SQLiteDialect, SnowflakeDialect,
+    AnsiDialect, BigQueryDialect, ClickHouseDialect, DuckDbDialect, GenericDialect, HiveDialect,
+    MsSqlDialect, MySqlDialect, PostgreSqlDialect, RedshiftSqlDialect, SQLiteDialect,
+    SnowflakeDialect,
 };
 use sqlparser::keywords::ALL_KEYWORDS;
 use sqlparser::parser::{Parser, ParserError, ParserOptions};
@@ -195,6 +196,7 @@ fn parse_update_set_from() {
     let dialects = TestedDialects {
         dialects: vec![
             Box::new(GenericDialect {}),
+            Box::new(DuckDbDialect {}),
             Box::new(PostgreSqlDialect {}),
             Box::new(BigQueryDialect {}),
             Box::new(SnowflakeDialect {}),
@@ -941,6 +943,7 @@ fn parse_exponent_in_select() -> Result<(), ParserError> {
             Box::new(AnsiDialect {}),
             Box::new(BigQueryDialect {}),
             Box::new(ClickHouseDialect {}),
+            Box::new(DuckDbDialect {}),
             Box::new(GenericDialect {}),
             // Box::new(HiveDialect {}),
             Box::new(MsSqlDialect {}),
@@ -2053,6 +2056,7 @@ fn parse_array_agg_func() {
     let supported_dialects = TestedDialects {
         dialects: vec![
             Box::new(GenericDialect {}),
+            Box::new(DuckDbDialect {}),
             Box::new(PostgreSqlDialect {}),
             Box::new(MsSqlDialect {}),
             Box::new(AnsiDialect {}),
@@ -2848,6 +2852,7 @@ fn parse_alter_table_add_column_if_not_exists() {
             Box::new(PostgreSqlDialect {}),
             Box::new(BigQueryDialect {}),
             Box::new(GenericDialect {}),
+            Box::new(DuckDbDialect {}),
         ],
         options: None,
     };
@@ -6139,6 +6144,7 @@ fn test_placeholder() {
     let dialects = TestedDialects {
         dialects: vec![
             Box::new(GenericDialect {}),
+            Box::new(DuckDbDialect {}),
             Box::new(PostgreSqlDialect {}),
             Box::new(MsSqlDialect {}),
             Box::new(AnsiDialect {}),
@@ -6873,6 +6879,7 @@ fn parse_non_latin_identifiers() {
     let supported_dialects = TestedDialects {
         dialects: vec![
             Box::new(GenericDialect {}),
+            Box::new(DuckDbDialect {}),
             Box::new(PostgreSqlDialect {}),
             Box::new(MsSqlDialect {}),
             Box::new(RedshiftSqlDialect {}),

tests/sqlparser_duckdb.rs

@@ -0,0 +1,70 @@
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#[macro_use]
+mod test_utils;
+
+use test_utils::*;
+
+use sqlparser::ast::*;
+use sqlparser::dialect::{DuckDbDialect, GenericDialect};
+
+fn duckdb() -> TestedDialects {
+    TestedDialects {
+        dialects: vec![Box::new(DuckDbDialect {})],
+        options: None,
+    }
+}
+
+fn duckdb_and_generic() -> TestedDialects {
+    TestedDialects {
+        dialects: vec![Box::new(DuckDbDialect {}), Box::new(GenericDialect {})],
+        options: None,
+    }
+}
+
+#[test]
+fn test_select_wildcard_with_exclude() {
+    let select = duckdb().verified_only_select("SELECT * EXCLUDE (col_a) FROM data");
+    let expected = SelectItem::Wildcard(WildcardAdditionalOptions {
+        opt_exclude: Some(ExcludeSelectItem::Multiple(vec![Ident::new("col_a")])),
+        ..Default::default()
+    });
+    assert_eq!(expected, select.projection[0]);
+
+    let select =
+        duckdb().verified_only_select("SELECT name.* EXCLUDE department_id FROM employee_table");
+    let expected = SelectItem::QualifiedWildcard(
+        ObjectName(vec![Ident::new("name")]),
+        WildcardAdditionalOptions {
+            opt_exclude: Some(ExcludeSelectItem::Single(Ident::new("department_id"))),
+            ..Default::default()
+        },
+    );
+    assert_eq!(expected, select.projection[0]);
+
+    let select = duckdb()
+        .verified_only_select("SELECT * EXCLUDE (department_id, employee_id) FROM employee_table");
+    let expected = SelectItem::Wildcard(WildcardAdditionalOptions {
+        opt_exclude: Some(ExcludeSelectItem::Multiple(vec![
+            Ident::new("department_id"),
+            Ident::new("employee_id"),
+        ])),
+        ..Default::default()
+    });
+    assert_eq!(expected, select.projection[0]);
+}
+
+#[test]
+fn parse_div_infix() {
+    duckdb_and_generic().verified_stmt(r#"SELECT 5 // 2"#);
+}