基本SQL语句

1.查询语句

select field1,field2... (*) from table1;

//从表table1中查询字段field1、field2

2.插入语句

insert into table1(field1,field2) values(value1,value2)

//向表table1中插入数据，其中字段field1值为value1，field2值为values

3.删除语句

delete from table1 where condition1 and condition
//从表table1中删除满足条件condition1和condition2的记录

4.更新语句

update table1 set field1=value1 where condition

//更新表table1,设置字段field1的值为value1

5.group by语句(与聚合函数配合使用)

select  sum(field1) from table1 group by field2;

//将记录按照字段field2分组，查询字段field1的分组和