select name "n", age "a", sex "s", height "h" from person;
（带上""双引号显示的和双引号里面的一样）
select name n, age a, sex s, height h from person;
（不带""双引号显示的是n、a、s、h的大写）
select name as "名字", age as "年龄", sex as "性别", height as "身高" from person;
（as可要可不要）
select name "n", age "a", sex "s", height "h" from person;
（带上""双引号显示的和双引号里面的一样）
select name n, age a, sex s, height h from person;
（不带""双引号显示的是n、a、s、h的大写）
select name as "名字", age as "年龄", sex as "性别", height as "身高" from person;
（as可要可不要）