
List<Test> t = new List<Test>() {
new Test(){id=,name="车辆"},
new Test(){id=,name="车辆"},
new Test(){id=,name="飞机"},
new Test(){id=,name="火车"},
new Test(){id=,name="火车"},
};
//同名
var q = t.GroupBy(x => x.name).Where(x => x.Count() > ).ToList(); foreach (var item in q)
{
Console.WriteLine(item.Key);
}
sql:
--重复的物品编码
SELECT COUNT(0) AS num,Code
FROM dbo.Goods
GROUP BY Code
HAVING COUNT(0)>1
ORDER BY Code