Mysql中通过关联update将一张表的一个字段更新到另外一张表中

update book_borrow br,student st set br.student_name = st.name where br.student_id = st.id;

update book_borrow br set student_name = (select name from student where id = br.student_id);
update book_borrow br left join student st on br.student_id = st.id set br.student_name = st.name;　　

-- insert into 表名1 （列名） select (列名) from 表名2 ;
insert into  tableA(columnA) select columnA from tableB where id=1