查找：select* from table1 where 范围
like查找：select * from table1 where field1 like '%value%'
select * from table2 where field2 like '1234%'
插入：insert into table1 (field1,field2)value（value1，value2）
删除：delete from table1 where 范围
更新：update table1 set field1 = value1 where 范围
排序：select * from table1 order by field1,field2 [desc]
总数：select count as totalcount from table1
求和：select sum(field1)as sumvalue from table1
平均：select avg(field1)as avgvalue from table1
最大：select max(field1)as maxvalue from table1
最小：select min(field1)as minvalue from table1
举例：
1.user表中，表字段为：name、email、password、loginTime；
写SQL：查询user表中用户名含有“测试”，并返回最近登录的前10条记录。 select* from user where name like '%测试%' order by loginTime desc limit 10;
select * from user u where u.name like '%测试%' order by loginTime desc limit 10;
2.找到pay库card表中的银行卡号bin_code开头为622848的卡;
select * from pay.'card_bin'a where a.bin_code like '622848%';
select * from pay.card b where b.bin_code like '622848%';
