数据库操作:
1.增:
insert into test(nid,name) values(1,'sam'),(2,'eric'); #键值对形式插入
insert into test values(3,'alex'); # 默认顺序
insert into test(nid,name) select nid,name from test1; #插入另一个表里的值
2.删:
delete from test;
delete from test where nid=1;
delete from test where nid between 1 and 7;
3.改:
update test set name='sam' where nid=2;
4.查:
select * from test;
select name from test where nid > 5 and name='sam';