查詢:一:查詢所有數據select * from Info 查所有數據select Code,Name from Info 查特定列二:根據條件查select * from Info where Code='p001' 一個條件查詢select * from Info where Code='p00 ...
查詢:
一:查詢所有數據
select * from Info 查所有數據
select Code,Name from Info 查特定列
二:根據條件查
select * from Info where Code='p001' 一個條件查詢
select * from Info where Code='p001' and Nation='n001' 多條件 並關係 查詢
select * from Info where Name='胡軍' or Nation='n001' 多條件 或關係 查詢
select * from Car where Price>=50 and Price<=60 範圍查詢
select * from Car where Price between 50 and 60 範圍查詢
三:模糊查詢
select * from Car where Name like '%型' %通配符代表任意多個字元
select * from Car where Name like '%奧迪%' _通配符代表任意一個字元
select * from Car where Name like '_馬%'
四:排序
select * from Car order by Price asc 按照價格升序排列
select * from Car order by Price desc 按照價格降序排列
select * from Car order by Price,Oil 按照兩列進行排序,前面的為主要的
五:統計函數(聚合函數)
select count(Code) from Car 查詢表中有多少條數據
select max(Price) from Car 取價格的最大值
select min(Price) from Car 取價格的最小值
select sum(Price) from Car 取價格的總和
select avg(Price) from Car 取價格的平均值
六:分組查詢
select Brand from Car group by Brand having count(*)>2 查詢所有系列中數量大於2的
七:分頁查詢
select * from Car limit 0,5 跳過幾條數據取幾條數據
八:去重查詢
select distinct Brand from Car