Redshift: Fix parsing for quoted numbered columns

src/dialect/redshift.rs

@@ -41,10 +41,19 @@ impl Dialect for RedshiftSqlDialect {
     /// treating them as json path. If there is identifier then we assume
     /// there is no json path.
     fn is_proper_identifier_inside_quotes(&self, mut chars: Peekable<Chars<'_>>) -> bool {
+        // PartiQL (used as json path query language in Redshift) uses square bracket as a start character and a quote is a beginning of quoted identifier
+        if let Some(quote_start) = chars.peek() {
+            if *quote_start == '"' {
+                return true;
+            }
+        };
         chars.next();
         let mut not_white_chars = chars.skip_while(|ch| ch.is_whitespace()).peekable();
         if let Some(&ch) = not_white_chars.peek() {
-            return self.is_identifier_start(ch);
+            // PartiQL uses single quote as starting identification inside a quote
+            // It is a normal identifier if it has no single quote at the beginning.
+            // Additionally square bracket can contain quoted identifier.
+            return ch == '"' || ch != '\'' && self.is_identifier_start(ch);
         }
         false
     }

tests/sqlparser_redshift.rs

@@ -279,6 +279,31 @@ fn test_redshift_json_path() {
         },
         expr_from_projection(only(&select.projection))
     );
+
+    let sql = r#"SELECT db1.sc1.tbl1.col1[0]."id" FROM customer_orders_lineitem"#;
+    let select = dialects.verified_only_select(sql);
+    assert_eq!(
+        &Expr::JsonAccess {
+            value: Box::new(Expr::CompoundIdentifier(vec![
+                Ident::new("db1"),
+                Ident::new("sc1"),
+                Ident::new("tbl1"),
+                Ident::new("col1")
+            ])),
+            path: JsonPath {
+                path: vec![
+                    JsonPathElem::Bracket {
+                        key: Expr::Value(Value::Number("0".parse().unwrap(), false))
+                    },
+                    JsonPathElem::Dot {
+                        key: "id".to_string(),
+                        quoted: true,
+                    }
+                ]
+            }
+        },
+        expr_from_projection(only(&select.projection))
+    );
 }
 
 #[test]
@@ -353,3 +378,17 @@ fn test_parse_json_path_from() {
         _ => panic!(),
     }
 }
+
+#[test]
+fn test_parse_select_numbered_columns() {
+    redshift_and_generic().verified_stmt(r#"SELECT 1 AS "1" FROM a"#);
+    // RedShift specific case - quoted identifier inside square bracket
+    redshift().verified_stmt(r#"SELECT 1 AS ["1"] FROM a"#);
+}
+
+#[test]
+fn test_parse_create_numbered_columns() {
+    redshift_and_generic().verified_stmt(
+        r#"CREATE TABLE test_table_1 ("1" INT, "d" VARCHAR(155), "2" DOUBLE PRECISION)"#,
+    );
+}