add support for databricks JSON accessors (#2272)

Author: whirlun

src/ast/mod.rs

@@ -651,6 +651,14 @@ pub enum JsonPathElem {
         /// The expression used as the bracket key (string or numeric expression).
         key: Expr,
     },
+    /// Access an object field using colon bracket notation
+    /// e.g. `obj:['foo']`
+    ///
+    /// See <https://docs.databricks.com/en/sql/language-manual/functions/colonsign.html>
+    ColonBracket {
+        /// The expression used as the bracket key (string or numeric expression).
+        key: Expr,
+    },
 }
 
 /// A JSON path.
@@ -685,6 +693,9 @@ impl fmt::Display for JsonPath {
                 JsonPathElem::Bracket { key } => {
                     write!(f, "[{key}]")?;
                 }
+                JsonPathElem::ColonBracket { key } => {
+                    write!(f, ":[{key}]")?;
+                }
             }
         }
         Ok(())

src/ast/spans.rs

@@ -1799,6 +1799,7 @@ impl Spanned for JsonPathElem {
         match self {
             JsonPathElem::Dot { .. } => Span::empty(),
             JsonPathElem::Bracket { key } => key.span(),
+            JsonPathElem::ColonBracket { key } => key.span(),
         }
     }
 }

src/parser/mod.rs

@@ -4195,8 +4195,9 @@ impl<'a> Parser<'a> {
         match token.token {
             Token::Word(Word {
                 value,
-                // path segments in SF dot notation can be unquoted or double-quoted
-                quote_style: quote_style @ (Some('"') | None),
+                // path segments in SF dot notation can be unquoted or double-quoted;
+                // Databricks also supports backtick-quoted identifiers
+                quote_style: quote_style @ (Some('"') | Some('`') | None),
                 // some experimentation suggests that snowflake permits
                 // any keyword here unquoted.
                 keyword: _,
@@ -4226,14 +4227,20 @@ impl<'a> Parser<'a> {
         let mut path = Vec::new();
         loop {
             match self.next_token().token {
+                Token::Colon if path.is_empty() && self.peek_token_ref() == &Token::LBracket => {
+                    self.next_token();
+                    let key = self.parse_wildcard_expr()?;
+                    self.expect_token(&Token::RBracket)?;
+                    path.push(JsonPathElem::ColonBracket { key });
+                }
                 Token::Colon if path.is_empty() => {
                     path.push(self.parse_json_path_object_key()?);
                 }
                 Token::Period if !path.is_empty() => {
                     path.push(self.parse_json_path_object_key()?);
                 }
                 Token::LBracket => {
-                    let key = self.parse_expr()?;
+                    let key = self.parse_wildcard_expr()?;
                     self.expect_token(&Token::RBracket)?;
 
                     path.push(JsonPathElem::Bracket { key });

tests/sqlparser_databricks.rs

@@ -600,3 +600,47 @@ fn parse_databricks_struct_type() {
         _ => unreachable!(),
     }
 }
+
+#[test]
+fn parse_databricks_json_accessor() {
+    // Basic colon accessor — unquoted field names are case-insensitive
+    databricks().verified_only_select("SELECT raw:owner, RAW:owner FROM store_data");
+
+    // Unquoted field access is case-insensitive; bracket notation is case-sensitive.
+    databricks().verified_only_select(
+        "SELECT raw:OWNER AS case_insensitive, raw:['OWNER'] AS case_sensitive FROM store_data",
+    );
+
+    // Backtick-quoted keys (Databricks delimited identifiers) normalise to double-quoted output.
+    databricks().one_statement_parses_to(
+        "SELECT raw:`zip code`, raw:`Zip Code`, raw:['fb:testid'] FROM store_data",
+        r#"SELECT raw:"zip code", raw:"Zip Code", raw:['fb:testid'] FROM store_data"#,
+    );
+
+    // Dot notation
+    databricks().verified_only_select("SELECT raw:store.bicycle FROM store_data");
+
+    // String-key bracket notation after a dot segment
+    databricks()
+        .verified_only_select("SELECT raw:store['bicycle'], raw:store['BICYCLE'] FROM store_data");
+
+    // Integer-index bracket notation
+    databricks()
+        .verified_only_select("SELECT raw:store.fruit[0], raw:store.fruit[1] FROM store_data");
+
+    // Wildcard [*] — including chained and mixed positions
+    databricks().verified_only_select(
+        "SELECT raw:store.basket[*], raw:store.basket[*][0] AS first_of_baskets, \
+         raw:store.basket[0][*] AS first_basket, raw:store.basket[*][*] AS all_elements_flattened, \
+         raw:store.basket[0][2].b AS subfield FROM store_data",
+    );
+
+    // Dot access following a wildcard bracket
+    databricks().verified_only_select("SELECT raw:store.book[*].isbn FROM store_data");
+
+    // Double-colon cast — type keyword normalises to upper case
+    databricks().one_statement_parses_to(
+        "SELECT raw:store.bicycle.price::double FROM store_data",
+        "SELECT raw:store.bicycle.price::DOUBLE FROM store_data",
+    );
+}