C# SQL table select 并计算不同的值

Question

我有 ASP 个网站和 SQL 个数据库 table。在此 table 列鬃毛 "type"。我想从该列中获取所有不同的值，这些值在 datatable 中计数。例如数据库 table:

id  type
---------
1   type1
2   type2
3   type3
4   type2
5   type2
6   type3

我想获取以下数据table:

type  count
------------
type1   1
type2   3
type3   2

Answer 1

我建议您在 sql 中使用以下查询

SELECT type, COUNT(type) as count
FROM myTableName 
GROUP BY type

Answer 2

您可以使用

SELECT type, COUNT(type) as count
FROM Table1 
GROUP BY type

结果

|  type | count |
|-------|-------|
| type1 |     1 |
| type2 |     3 |
| type3 |     2 |

Answer 3

SQL

SELECT type, COUNT(type) as count
FROM Table1 
GROUP BY type

林克

from t in <YourEntityObject>.YourTableName 
group t by t.type into myVar 
select new
   {
         k = myVar.Key,
         c = myVar.Count()
   };

C# SQL table select and count distinct values