mysql - 计算mysql中的各个行

Question

我有以下贷款模式:

mysql> select * from borrower;
+----------+---------+
| name     | loan_id |
+----------+---------+
| Adams    | L16     |
| Curry    | L93     |
| Hayes    | L15     |
| Jackson  | L14     |
| Jones    | L17     |
| Smith    | L11     |
| Smith    | L23     |
| Williams | L17     |
+----------+---------+
8 rows in set (0.00 sec)

我需要计算每个人获得的贷款总数。我认为自连接是解决这个问题的方法，我尝试了以下查询:

select T1.name, count(T2.name) from borrower T1, borrower T2 where T1.name = T2.name;

但是我得到了如下奇怪的结果:

mysql> select T1.name, count(T2.name) from borrower T1, borrower T2 where T1.name = T2.name;
+-------+----------------+
| name  | count(T2.name) |
+-------+----------------+
| Adams |             10 |
+-------+----------------+
1 row in set (0.00 sec)

Answer 1

你可以试试这个:

select name, count(name) from borrower
group by name