ROW_NUMBER、RANK()、DENSE_RANK()和OVER的使用

/*以FoodPrice列排序並顯示排序后的行號*/
SELECT ROW_NUMBER() OVER(ORDER BY FoodPrice DESC) AS RowId,* FROM dbo.Food

 

 

ROW_NUMBER()

/*以FoodType分組，然后以FoodPrice排序並顯示所在分組的相應行號*/
SELECT ROW_NUMBER() OVER(PARTITION BY FoodType ORDER BY FoodPrice DESC) AS RowId,* FROM dbo.Food

 

 

RANK()

/*以FoodType分組，然后以FoodPrice排序並顯示所在分組的相應行號，如果排序字段字相等則顯示相同的行號，
並跳過所在的真實行號*/
SELECT RANK() OVER(PARTITION BY FoodType ORDER BY FoodPrice) AS RowID,* FROM dbo.Food

 

 

 

DENSE_RANK()

/*以FoodType分組，然后以FoodPrice排序並顯示所在分組的相應行號，如果排序字段字相等則顯示相同的行號，
忽略相同行號，依次遞增*/
SELECT DENSE_RANK() OVER(PARTITION BY FoodType ORDER BY FoodPrice) AS RowID,* FROM dbo.Food