我有一个表,比如t1
我有A1、A2、a3、a4、a5列
我需要像一样的输出
A -column name
A1-value in a1
A2-value in a2
A3
A4
看起来像UNION
。
select a1 as a from t1 union all
select a2 from t1 union all
select a3 from t1 ...