操作数据库
–创建数据库
create database dbname;
–删除数据库
drop database dbname;
操作表
–新建表：
create table table1( id varchar(300) primary key, name varchar(200) not null);
–插入数据
insert into table1 (id,name) values (‘aa’,‘bb’);
–更新数据
update table1 set id = ‘bb’ where id=‘cc’;
–删除数据
delete from table1 where id =‘cc’;
–删除表
drop table table1;
–修改表名：
alter table table1 rename to table2;
–表数据复制：
insert into table1 (select * from table2);
–复制表结构：
create table table1 select * from table2 where 1>1;
–复制表结构和数据：
create table table1 select * from table2;
–复制指定字段：
create table table1 as select id, name from table2 where 1>1;
查询语句汇总
–查询所有字段
select * from table1
–查询指定字段
select name from table1
–where查询指定数据
select * from table1 where name = ‘李四’;
–带in关键字的查询
select * from table1 where age in (17,18,19);
–带between and查询
select * from table1 where age between 20 and 30;
–带like的模糊查询（’%‘代表任意个,’'代表一个）
select * from table1 where name like ‘张%’;
select * from table1 where name like '李斯’;
–空值查询
select * from table1 where tel is not null;
–带and的多条件查询
select * from table1 where name = ‘王欢’ and sex =‘男’;
–带or的多条件查找
select * from table1 where name = ‘王欢’ or age = 15;
–distinct去重复查询
select name from table1;//不去重复，相同的值也会显示出来
select distinct name from table1 ;//去除重复，相同的值只显示一次
–对查询结果排序（order by）
select * from table1 order by age;
–group by 分组查询
与group_concat()函数一起使用
select bookTypeId,group_concat(author) from t_book group by bookTypeId;
与聚合函数一起使用
select bookTypeId,count(bookName) from t_book group by bookTypeId;
与having函数一起使用（限制输出的结果）
select bookTypeId,count(author) from t_book group by bookTypeId having count(author)❤️;
与with rollup一起使用（最后一行会输出统计后的记录数据）
select bookTypeId,count(bookName) from t_book group by bookTypeId with rollup;
select bookTypeId,group_concat(author) from t_book group by bookTypeId with rollup;
–limit 分页查询
select * from t_book limit 0,3；//显示第一页三条记录