string、char[] 相互转换
使用String.valueOf()将字符数组转换成字符串
void (){
char[] s={'A','G','C','T'};
String st=String.valueOf(s);
System.out.println("This is : "+st);
}
使用.toCharArray()将字符串转换成字符数组
String st="AGCT";
char[] s=st.toCharArray();
for (int i=0;i<st.length();i++){
System.out.println("This s[i]"+i+s[i]);
}
select name from user where user_id in (select distinct user_id from blog where add_time='2018-05-30') ;
select * from user right join
(select user_id,count(*) num from blog where add_time between '2018-05-01' and '2018-05-31' group by user_id order by num desc limit 10) k
on user.id=k.user_id