mysql -A不预读数据库信息(use dbname 更快)—Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -Ahttps://img-blog.csdn.net/2016071600463

日期和字符转换函数用法（to_date,to_char）select to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss’) as nowTime from dual;//日期转化为字符串select to_char(sysdate,‘yyyy’) as nowYearfrom dual;//获取时间的年select to_char(sysdate,‘mm’)as now