SQL Group基于列值的行

Question

示例地址表

ID, EmployeeID, Address

1, 100, TownA
2, 200, TownA
3, 300, TownB

如何为每个唯一地址返回所有雇员的计数？

e.g

EmployeeCount, Address

2 TownA
1, TownB

Answer 1

你应该按照这一点做点什么。

SELECT count(EmployeeID) as EmployeeCount, Address FROM table GROUP BY Address

Answer 2

这是一个简单的分组

SELECT Count(*) EmployeeCount, Address
FROM yourTable
GROUP BY Address