select * from shuiguo 查询表 select * from shuiguo where jiage between 5 and 7 ( between 表示大于等于 5 且小于等于 7 的范围) select distinct name from shuiguo -- 去除重复,只针对一列 select * from shuiguo where name = ' 苹果 ' and chandi
select * from shuiguo 查询表
select * from shuiguo where jiage between 5 and 7 ( between 表示大于等于 5 且小于等于 7 的范围)
select distinct name from shuiguo -- 去除重复,只针对一列
select * from shuiguo where name = ' 苹果 ' and chandi = ' 海南 '
select * from shuiguo where name in( ' 苹果 ' , ' 香蕉 ' ) --name 只包含苹果,香蕉的
select * from shuiguo where name not in( ' 苹果 ' , ' 香蕉 ' ) --name 中除了苹果,香蕉的
select * from shuiguo where name like '% 苹 %' -- 模糊查询, % 叫通配符( % 在前面表示前面有任何字符, % 在后面表示后面有任何字符)
select * from shuiguo where name like ' 苹 _' -- 下划线表示任意一个字符
select * from shuiguo order by jiage -- 升序排列
select * from shuiguo order by jiage desc -- 降序排列
select top 2 * from shuiguo order by jiage -- 按升序排列,只取前两行( top 2 )
select top 1 * from shuiguo where name = ' 苹果 ' order by jiage desc -- 按照条件查询后排序,查名字叫苹果的谁的价格高,只选第一个
delete from shuiguo where chandi = ' 烟台 ' -- 删除水果表中产地是烟台的数据
alter table shuiguo add dianhua int -- 添加列名电话
update shuiguo set dianhua = 2 2 55557 where code = 2 -- 定义第几行的电话是多少
修改表加入新列 alter table abc add dianhua int
修改表删除一列 alter table abc drop column dianhua