1443
1443
select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
1444
1444
id select_type table type possible_keys key key_len ref rows Extra
1445
1445
1 SIMPLE Y ALL NULL NULL NULL NULL 2 Using temporary; Using filesort
1447
1447
select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;