/// <summary>
/// 查找历史数据最小值
/// </summary>
/// <param name="tagName"></param>
/// <returns></returns>
public static double MinOfHistory(string tagName)
{
try
{
string filtString = "tagName=" + "'" + tagName + "'";
DataRow[] drs = HistoryDataTable.Select(filtString);
//return decimal.Parse(dr[2].ToString());//返回查找到的数值
double min = double.MaxValue;
foreach (DataRow dr in drs)
{
double d = double.Parse(dr[2].ToString());
if (d < min)
{
min = d;
}
}
return(min);
}
catch (Exception ex)
{
return(0);
throw ex; //抛出异常
}
}
/// <summary>
/// 读取历史数据
/// </summary>
/// <param name="tagName"></param>
/// <param name="dateTime"></param>
/// <returns></returns>
public static decimal GetHistoryData(string tagName, string dateTime)
{
try
{
string filtString = "time=" + "'" + dateTime + "'" + " and tagName=" + "'" + tagName + "'";
DataRow dr = HistoryDataTable.Select(filtString).First();
return(decimal.Parse(dr[2].ToString()));//返回查找到的数值
}
catch (Exception ex)
{
return(0);
throw ex;//抛出异常
}
}
/// <summary>
/// 历史数据第一个值
/// </summary>
/// <param name="tagName"></param>
/// <returns></returns>
public static double firstOfHistory(string tagName)
{
double value = 0.0;
try
{
string filtString = "tagName=" + "'" + tagName + "'";
DataRow[] drs = HistoryDataTable.Select(filtString);
value = double.Parse(drs.First()[2].ToString());
return(value);
}
catch (Exception ex)
{
return(0);
throw ex; //抛出异常
}
}
/// <summary>
/// 历史数据求和
/// </summary>
/// <param name="tagName"></param>
/// <returns></returns>
public static decimal GetHistoryDataSum(string tagName, int exceptFirst)
{
//exceptFirst 是否舍去8点的数据,这里并不具有通用型,后续需要钙胶囊
try
{
string filtString = "tagName=" + "'" + tagName + "'";
DataRow[] drs = HistoryDataTable.Select(filtString);
int firstHour = DateTime.Parse(drs[0][0].ToString()).Hour;
decimal sum = 0;
if (exceptFirst == 0)
{
for (int i = 0; i < drs.Length; i++)
{
sum += decimal.Parse(drs[i][2].ToString());
}
}
else
{
if (firstHour == 8)
{
for (int i = 1; i < drs.Length; i++)
{
sum += decimal.Parse(drs[i][2].ToString());
}
}
else
{
for (int i = 0; i < drs.Length; i++)
{
sum += decimal.Parse(drs[i][2].ToString());
}
}
}
return(sum);
}
catch (Exception ex)
{
return(0);
throw ex; //抛出异常
}
}
/// <summary>
/// 计算历史数据平均值
/// </summary>
/// <param name="tagName"></param>
/// <returns></returns>
public static double avgOfHistory(string tagName)
{
try
{
string filtString = "tagName=" + "'" + tagName + "'";
DataRow[] drs = HistoryDataTable.Select(filtString);
//return decimal.Parse(dr[2].ToString());//返回查找到的数值
double avg = 0.0;
double sum = 0.0;
foreach (DataRow dr in drs)
{
double d = double.Parse(dr[2].ToString());
sum += d;
}
avg = sum / drs.Length;
return(avg);
}
catch (Exception ex)
{
return(0);
throw ex; //抛出异常
}
}