MySQL查询获取字段中所有元素的计数？
为此，请使用COUNT()方法。让我们首先创建一个表-
mysql> create table DemoTable -> ( -> ProductName varchar(100) -> );
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable values('Product-1');
mysql> insert into DemoTable values('Product-2');
mysql> insert into DemoTable values('Product-3');
mysql> insert into DemoTable values('Product-3');
mysql> insert into DemoTable values('Product-2');
mysql> insert into DemoTable values('Product-4');
mysql> insert into DemoTable values('Product-5');
mysql> insert into DemoTable values('Product-1');使用select语句显示表中的所有记录-
mysql> select *from DemoTable;
输出结果
这将产生以下输出-
+-------------+ | ProductName | +-------------+ | Product-1 | | Product-2 | | Product-3 | | Product-3 | | Product-2 | | Product-4 | | Product-5 | | Product-1 | +-------------+ 8 rows in set (0.00 sec)
以下是获取字段中所有元素计数的查询-
mysql> select ProductName,count(ProductName) as TotalCount from DemoTable group by ProductName;
输出结果
这将产生以下输出-
+-------------+------------+ | ProductName | TotalCount | +-------------+------------+ | Product-1 | 2 | | Product-2 | 2 | | Product-3 | 2 | | Product-4 | 1 | | Product-5 | 1 | +-------------+------------+ 5 rows in set (0.05 sec)