SQL学习笔记八 索引,表连接,子查询,ROW_NUMBER
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2023-12-09 15:51:09
索引 经常要查询的语句,则给它建一个索引 表连接 select t_oders as o join t_customers as c on o.customerid = c...
索引
经常要查询的语句,则给它建一个索引
表连接
select t_oders as o join t_customers as c on o.customerid = c.id
子查询
单值子查询
单列多值子查询
row_number()函数
row_number() over(order by fsalary desc)
经常要查询的语句,则给它建一个索引
表连接
select t_oders as o join t_customers as c on o.customerid = c.id
子查询
单值子查询
单列多值子查询
row_number()函数
row_number() over(order by fsalary desc)