Support date 'key' when using semi structured data (#1023)

tests/sqlparser_snowflake.rs

@@ -208,6 +208,17 @@ fn parse_json_using_colon() {
         select.projection[0]
     );
 
+    let sql = "SELECT a:date FROM t";
+    let select = snowflake().verified_only_select(sql);
+    assert_eq!(
+        SelectItem::UnnamedExpr(Expr::JsonAccess {
+            left: Box::new(Expr::Identifier(Ident::new("a"))),
+            operator: JsonOperator::Colon,
+            right: Box::new(Expr::Value(Value::UnQuotedString("date".to_string()))),
+        }),
+        select.projection[0]
+    );
+
     snowflake().one_statement_parses_to("SELECT a:b::int FROM t", "SELECT CAST(a:b AS INT) FROM t");
 }