如何使用MySQL显示同一行中不同记录的计数？
为此，您可以将GROUP_CONCAT()COUNT()与GROUPBY子句一起使用。让我们首先创建一个表-
mysql> create table DemoTable -> ( -> CompanyId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> CompanyName varchar(20) -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable(CompanyName) values('Amazon');
mysql> insert into DemoTable(CompanyName) values('Google');
mysql> insert into DemoTable(CompanyName) values('Google');
mysql> insert into DemoTable(CompanyName) values('Microsoft');
mysql> insert into DemoTable(CompanyName) values('Amazon');
mysql> insert into DemoTable(CompanyName) values('Amazon');使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
+-----------+-------------+ | CompanyId | CompanyName | +-----------+-------------+ | 1 |Amazon | | 2 |Google | | 3 |Google | | 4 |Microsoft | | 5 |Amazon | | 6 |Amazon | +-----------+-------------+ 6 rows in set (0.00 sec)
这是显示与MySQL同一行中不同记录的计数的查询-
mysql> select CompanyName,group_concat(CompanyId),count(CompanyId) as count from DemoTable -> group by CompanyName -> having count > 1;
这将产生以下输出-
+-------------+-------------------------+-------+ | CompanyName | group_concat(CompanyId) | count | +-------------+-------------------------+-------+ | Amazon | 1,5,6 | 3 | | Google | 2,3 | 2 | +-------------+-------------------------+-------+ 2 rows in set (0.00 sec)