SQL对同一列中的项进行计数

Question

我有一张包含以下记录的表格：

BookingTimeStamp    BookingReloc    AEType
2016-01-14 23:19:24.773 LVWCQL  Seat
2016-01-14 23:19:24.773 LVWCQL  Seat
2016-01-14 23:19:24.773 LVWCQL  Seat
2016-01-14 16:45:29.450 KCCEMG  Baggage
2016-01-14 16:34:07.117 MEZYPN  Insurance
2016-01-14 16:08:40.617 CJXDFK  Insurance
2016-01-14 16:08:40.617 CJXDFK  Insurance
2016-01-14 16:08:40.617 CJXDFK  Insurance
2016-01-14 16:08:40.617 CJXDFK  Insurance
2016-01-14 15:14:51.633 JMILRY  Seat

我想计算AEType列中值的重复次数。

期望的输出：

Seat = 4 

Baggaage = 1

Insurance =5

是否可以在单个查询中获取它？

Answer 1

select AEType,count(*) from table_name
group by AEType;

Answer 2

使用'group by'它通过distinct参数对sql条目进行分组，'count（*）'可用于计算每个不同AEType的sql条目数。

select AEType,count(*) from Table_Name group by AEType;