Statistical query of SQL Server database

Basic database table Table by ：

Inquire about Table The maximum value of a field in the table , minimum value , Average, etc .

select MAX(Age) AS Maximum age ,min(Age) AS Minimum age ,avg(Age) AS Average age from Table

Query results ：

Use group by Statistics query （ male / Woman ） The number of

select Sex AS Gender ,COUNT(*) AS The number of from Table1 group by Sex

Query results ：

Use group by Statistics query You can also query multiple fields （ Gender and address ）

select Adderss AS home ,Sex AS Gender ,COUNT(*) AS The number of from Table group by Sex,Adderss

Query results ：

Use having The number of conditional statistics queries is greater than 2 People's place

select Adderss AS Address ,COUNT(*) AS The number of from Table group by Adderss having COUNT(*)>=2

Query results ：