所以我一般在 LINQ 和数据库方面不是很强，所以请理解我知道我是新手。我正在尝试从系统中获取有关员工活动的信息。这是问题所在，我有 4 个 mysql 查询将表返回给我。我得到这样的信息
private DataTable GetBreaks()
{
server = "someip";
database = "calls";
uid = "user";
password = "password";
int port = 999999;
string connectionString;
connectionString = "server=" + server + ";" + "database=" + database + ";" + "port=3306;" + "user=" + uid + ";" + "password=" + password + ";";
connection = new MySqlConnection(connectionString);
if (this.OpenConnection() == true)
{
DataSet dt = new DataSet();
DateTime endDateRun = radDateTimePicker2.Value.Date;
DateTime endDate;
DateTime startDate = radDateTimePicker1.Value.Date;
if (endDateRun != startDate)
{
do
{
endDate = startDate.AddDays(1);
string start = startDate.ToString("yyyy-MM-dd HH:mm:ss");
string end = endDate.ToString("yyyy-MM-dd HH:mm:ss");
string standard = "SELECT number, agent, break, (SUM(TIME_TO_SEC(duration))) AS Total FROM agentBreaks WHERE (datetime_init > '+ start +' and datetime_init < '+ end+' ) and (break= '15 Minute') GROUP BY break,agent
" + "join break on (audit.id_break = break.id) where (datetime_init >'" + start + "' and datetime_init < '" + end + "') and (break.name = '15 Minute') GROUP BY break.name,agent"; mySqlDataAdapter = new MySqlDataAdapter(standard, connection); DataSet DS = new DataSet(); mySqlDataAdapter.Fill(DS);
DS.Tables[0].Columns.Add(new DataColumn("date"));
for (int i = 0; i <= DS.Tables[0].Rows.Count - 1; i++)
{
DS.Tables[0].Rows[i]["date"] = startDate.ToString();
}
dt.Merge(DS);
startDate = startDate.AddDays(1);
} while (endDateRun != endDate);
}
//close connection
this.CloseConnection();
return dt.Tables[0];
}
return null;
}
然后我得到其他结果并尝试使用 Linq 加入它们：
protected void CreateUnifiedTable()
{
DataTable Merged;
DataTable dt1 = GetClockin();
DataTable dt2 = GetLunch();
DataTable dt3 = GetBreaks();
DataTable dt4 = GetOther();
var myLINQ = from DataTable t1 in dt1.AsEnumerable()
join t2 in dt2.AsEnumerable() on new { t1.id_agent, t1.date } equals new { t2.id_agent, t2.Columnsdate }
join t3 in dt3.AsEnumerable() on new { t1.id_agent, t1.date } equals new { t3.id_agent, t3.Columnsdate }
join t4 in dt4.AsEnumerable() on new { t1.id_agent, t1.date } equals new { t4.id_agent, t4.Columnsdate }
select new
{
name = t1.Field<string>("agent"),
login = t1.Field<DateTime>("Login"),
fifteenMinute = t3.Field<TimeSpan>("Total"),
lunch = t2.Field<TimeSpan>("Total"),
other = t4.Field<TimeSpan>("Total"),
logout = t1.Field<TimeSpan>("Logout"),
total = t1.Field<TimeSpan>("Total") - t2.Field<TimeSpan> "Total")
};
}
但我得到的只是这个错误找不到源类型'System.Data.EnumerableRowCollection'的查询模式的实现。未找到“加入”。您是否缺少“System.Linq”的引用或使用指令？
编辑：
由于匿名数据类型，我无法让 myLinq 正确绑定为 DataTable 知道我在做什么错吗？