Initial Databricks SQL dialect (apache#1220)

Author: jmhain

src/dialect/databricks.rs

@@ -0,0 +1,32 @@
+use crate::dialect::Dialect;
+
+/// A [`Dialect`] for [Databricks SQL](https://www.databricks.com/)
+///
+/// See <https://docs.databricks.com/en/sql/language-manual/index.html>.
+#[derive(Debug, Default)]
+pub struct DatabricksDialect;
+
+impl Dialect for DatabricksDialect {
+    // see https://docs.databricks.com/en/sql/language-manual/sql-ref-identifiers.html
+
+    fn is_delimited_identifier_start(&self, ch: char) -> bool {
+        matches!(ch, '`')
+    }
+
+    fn is_identifier_start(&self, ch: char) -> bool {
+        matches!(ch, 'a'..='z' | 'A'..='Z' | '_')
+    }
+
+    fn is_identifier_part(&self, ch: char) -> bool {
+        matches!(ch, 'a'..='z' | 'A'..='Z' | '0'..='9' | '_')
+    }
+
+    fn supports_filter_during_aggregation(&self) -> bool {
+        true
+    }
+
+    // https://docs.databricks.com/en/sql/language-manual/sql-ref-syntax-qry-select-groupby.html
+    fn supports_group_by_expr(&self) -> bool {
+        true
+    }
+}

src/dialect/mod.rs

@@ -13,6 +13,7 @@
 mod ansi;
 mod bigquery;
 mod clickhouse;
+mod databricks;
 mod duckdb;
 mod generic;
 mod hive;
@@ -32,6 +33,7 @@ use core::str::Chars;
 pub use self::ansi::AnsiDialect;
 pub use self::bigquery::BigQueryDialect;
 pub use self::clickhouse::ClickHouseDialect;
+pub use self::databricks::DatabricksDialect;
 pub use self::duckdb::DuckDbDialect;
 pub use self::generic::GenericDialect;
 pub use self::hive::HiveDialect;

src/test_utils.rs

@@ -207,6 +207,7 @@ pub fn all_dialects() -> TestedDialects {
         Box::new(BigQueryDialect {}) as Box<dyn Dialect>,
         Box::new(SQLiteDialect {}) as Box<dyn Dialect>,
         Box::new(DuckDbDialect {}) as Box<dyn Dialect>,
+        Box::new(DatabricksDialect {}) as Box<dyn Dialect>,
     ];
     TestedDialects {
         dialects: all_dialects,

tests/sqlparser_common.rs

@@ -8937,6 +8937,76 @@ fn parse_map_access_expr() {
     }
 }
 
+#[test]
+fn test_selective_aggregation() {
+    let sql = concat!(
+        "SELECT ",
+        "ARRAY_AGG(name) FILTER (WHERE name IS NOT NULL), ",
+        "ARRAY_AGG(name) FILTER (WHERE name LIKE 'a%') AS agg2 ",
+        "FROM region"
+    );
+    assert_eq!(
+        all_dialects_where(|d| d.supports_filter_during_aggregation())
+            .verified_only_select(sql)
+            .projection,
+        vec![
+            SelectItem::UnnamedExpr(Expr::AggregateExpressionWithFilter {
+                expr: Box::new(Expr::ArrayAgg(ArrayAgg {
+                    distinct: false,
+                    expr: Box::new(Expr::Identifier(Ident::new("name"))),
+                    order_by: None,
+                    limit: None,
+                    within_group: false,
+                })),
+                filter: Box::new(Expr::IsNotNull(Box::new(Expr::Identifier(Ident::new(
+                    "name"
+                ))))),
+            }),
+            SelectItem::ExprWithAlias {
+                expr: Expr::AggregateExpressionWithFilter {
+                    expr: Box::new(Expr::ArrayAgg(ArrayAgg {
+                        distinct: false,
+                        expr: Box::new(Expr::Identifier(Ident::new("name"))),
+                        order_by: None,
+                        limit: None,
+                        within_group: false,
+                    })),
+                    filter: Box::new(Expr::Like {
+                        negated: false,
+                        expr: Box::new(Expr::Identifier(Ident::new("name"))),
+                        pattern: Box::new(Expr::Value(Value::SingleQuotedString("a%".to_owned()))),
+                        escape_char: None,
+                    }),
+                },
+                alias: Ident::new("agg2")
+            },
+        ]
+    )
+}
+
+#[test]
+fn test_group_by_grouping_sets() {
+    let sql = concat!(
+        "SELECT city, car_model, sum(quantity) AS sum ",
+        "FROM dealer ",
+        "GROUP BY GROUPING SETS ((city, car_model), (city), (car_model), ()) ",
+        "ORDER BY city",
+    );
+    assert_eq!(
+        all_dialects_where(|d| d.supports_group_by_expr())
+            .verified_only_select(sql)
+            .group_by,
+        GroupByExpr::Expressions(vec![Expr::GroupingSets(vec![
+            vec![
+                Expr::Identifier(Ident::new("city")),
+                Expr::Identifier(Ident::new("car_model"))
+            ],
+            vec![Expr::Identifier(Ident::new("city")),],
+            vec![Expr::Identifier(Ident::new("car_model"))],
+            vec![]
+        ])])
+    );
+}
 #[test]
 fn test_match_recognize() {
     use MatchRecognizePattern::*;

tests/sqlparser_databricks.rs

@@ -0,0 +1,30 @@
+use sqlparser::ast::*;
+use sqlparser::dialect::DatabricksDialect;
+use test_utils::*;
+
+#[macro_use]
+mod test_utils;
+
+fn databricks() -> TestedDialects {
+    TestedDialects {
+        dialects: vec![Box::new(DatabricksDialect {})],
+        options: None,
+    }
+}
+
+#[test]
+fn test_databricks_identifiers() {
+    // databricks uses backtick for delimited identifiers
+    assert_eq!(
+        databricks().verified_only_select("SELECT `Ä`").projection[0],
+        SelectItem::UnnamedExpr(Expr::Identifier(Ident::with_quote('`', "Ä")))
+    );
+
+    // double quotes produce string literals, not delimited identifiers
+    assert_eq!(
+        databricks()
+            .verified_only_select(r#"SELECT "Ä""#)
+            .projection[0],
+        SelectItem::UnnamedExpr(Expr::Value(Value::DoubleQuotedString("Ä".to_owned())))
+    );
+}

tests/sqlparser_hive.rs

@@ -336,24 +336,6 @@ fn parse_create_function() {
     );
 }
 
-#[test]
-fn filtering_during_aggregation() {
-    let rename = "SELECT \
-        ARRAY_AGG(name) FILTER (WHERE name IS NOT NULL), \
-        ARRAY_AGG(name) FILTER (WHERE name LIKE 'a%') \
-        FROM region";
-    println!("{}", hive().verified_stmt(rename));
-}
-
-#[test]
-fn filtering_during_aggregation_aliased() {
-    let rename = "SELECT \
-        ARRAY_AGG(name) FILTER (WHERE name IS NOT NULL) AS agg1, \
-        ARRAY_AGG(name) FILTER (WHERE name LIKE 'a%') AS agg2 \
-        FROM region";
-    println!("{}", hive().verified_stmt(rename));
-}
-
 #[test]
 fn filter_as_alias() {
     let sql = "SELECT name filter FROM region";