Nested alias doesn't work

[waitingkuo]

from apache/datafusion#2867

while we have nested alias, the outer doesn't work

use sqlparser::dialect::GenericDialect;
use sqlparser::parser::Parser;

fn main() {

 let dialect = GenericDialect {}; // or AnsiDialect

 let sql = "SELECT __t404.__c394, __t404.__c395, __t404.__c396, __t404.__c397
 FROM ((
 (SELECT test1.c0 AS __c394, test1.c1 AS __c395, test1.c2 AS __c396, test1.c3 AS __c397
 FROM (test1)) __t398
 INNER JOIN
 (SELECT test1.c0 AS __c399, test1.c1 AS __c400, test1.c2 AS __c401, test1.c3 AS __c402
 FROM (test1)) __t403
 ON __t398.__c395 = __t403.__c401) __t404)
 WHERE __t404.__c395 != __t404.__c396; ";



 let ast = Parser::parse_sql(&dialect, sql).unwrap();

 println!("AST: {:?}", ast);
} 

➜ sp git:(master) ✗ cargo run
 Compiling sp v0.1.0 (/Users/willy/willy/df-workspace/sp)
 Finished dev [unoptimized + debuginfo] target(s) in 0.30s
 Running `target/debug/sp`
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ParserError("Expected ), found: __t404")', src/main.rs:26:48
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

while this works

use sqlparser::dialect::GenericDialect;
use sqlparser::parser::Parser;
 
fn main() { 
 
 let dialect = GenericDialect {}; // or AnsiDialect

 /* 
 let sql = "SELECT a, b, 123, myfunc(b) \
 FROM table_1 \
 WHERE a > b AND b < 100 \
 ORDER BY a DESC, b";
 */
 let sql = "SELECT __c394, __c395, __c396, __c397
 FROM ((
 (SELECT test1.c0 AS __c394, test1.c1 AS __c395, test1.c2 AS __c396, test1.c3 AS __c397
 FROM (test1)) __t398
 INNER JOIN
 (SELECT test1.c0 AS __c399, test1.c1 AS __c400, test1.c2 AS __c401, test1.c3 AS __c402
 FROM (test1)) __t403
 ON __t398.__c395 = __t403.__c401) )
 WHERE __c395 != __c396; ";

 

 let ast = Parser::parse_sql(&dialect, sql).unwrap();

 println!("AST: {:?}", ast);
}