1 查询字段的实际长度
select column_a, length(replace(column_a,' ')) from tname;
2 知识点补充
2.1 length()函数
参考:https:///qq_40588579/article/details/86109556
2.2 replace()函数
replace函数有两个常用方法
select replace('abcdef h',' ','g') from dual;
>>> abcdefgh
select replace('acdef h',' ') from dual;
>>> abcdefh