数据库sql基础语句_百度文库

1、一、 创建数据库、表1）创建数据库create database 数据库名create database AA2 删除数据库Drop database数据库名Drop database AA3 创建表Create table 表名( Column1 data_type ,Column2 data_type,Column3 data_type;注意每行定义后用，隔开，最后语句末用；隔开还可以定义列字段的约束条件，其中not null,primary key,foreign key例如：Create table bb( a varchar(20 not null,b int(20,c char(2

2、0; bb表：abc4）删除表Drop table 表名Drop table aa5 修改表Alter关键字对表进行修改 5.1 增加新列，关键字addalter table bb add d char(10在bb表中增加一列dabcd5.2重命名列，关键字changeAlter table bb change c cd char(20abcdd5.3 删除列，关键字dropAlter table bb drop column bacdd5.4 修改列名Alter table bb chang a a varchar(10 primary keyacdd主键6 重命名表名Alter table

3、 bb rename dd 二、 select查询语句1） 简单的select 语句Select * from bb注解：显示出bb表中的所有列排除重复行，distinctSelect distinct (a from bb 2）Select b from bb where +条件注解：显示满足条件的所有b值b为要查询的字段attribute-listfrom 从哪张表中取数 table-namewhere 设置的筛选条件condition3 显示前10条记录TopSelect top 10 * from bb 4 比较符>,<,>=,<=,Select * from

4、where b>10005 逻辑符 or , andSelect a from bb where b>100 and b<2006 范围 in, between and Select * from bb where b in(100,200,300Select a from bb where b between 100 and 5007 匹配符 likeSelect a from bb where a likes%说明：%代表任意长度的字符，_代表单个字符，？代表任意字符聚合函数Sum(,count(,avg(,group by, order by 8 select sum(

5、a from bb 9 select count(b from bb group by a 10 select a,b from bb group by a having sum(b>10011 select b from bb where b desc排序默认升序，asc一般缺省，desc为降序关键字Select嵌套查询Select in select12）Select a from bb where c in (select c from bb b>100Select join连接语句连接语句是1个(自身连接或多个表做连接，inner join, out join(left join ,right join ,Self join12 Select a from bb B join cc C on B.id=C.id三 、insert与update 语句向表中插入数据13 Insert into table (column1,column2,column3values(更改表中数据14 update table set a=更改的值 where+条件condition四、delete语句delete from table where +condition五、SQL中的视图（view）,索引（index）,触发器（trigger），存储过程（procedu