Redshift - Add support in sharp as start of the field name (apache#485)

* Add support in sharp

* CR Review

Author: yuval-illumex

src/dialect/redshift.rs

@@ -44,10 +44,12 @@ impl Dialect for RedshiftSqlDialect {
     }
 
     fn is_identifier_start(&self, ch: char) -> bool {
-        PostgreSqlDialect {}.is_identifier_start(ch)
+        // Extends Postgres dialect with sharp
+        PostgreSqlDialect {}.is_identifier_start(ch) || ch == '#'
     }
 
     fn is_identifier_part(&self, ch: char) -> bool {
-        PostgreSqlDialect {}.is_identifier_part(ch)
+        // Extends Postgres dialect with sharp
+        PostgreSqlDialect {}.is_identifier_part(ch) || ch == '#'
     }
 }

tests/sqlparser_redshift.rs

@@ -100,3 +100,13 @@ fn redshift() -> TestedDialects {
         dialects: vec![Box::new(RedshiftSqlDialect {})],
     }
 }
+
+#[test]
+fn test_sharp() {
+    let sql = "SELECT #_of_values";
+    let select = redshift().verified_only_select(sql);
+    assert_eq!(
+        SelectItem::UnnamedExpr(Expr::Identifier(Ident::new("#_of_values"))),
+        select.projection[0]
+    );
+}