我正在学习Typed Dataset,
有一个辅助方法,它采用程序名称&返回DataTable,
public static DataTable ExecuteProcedureReturnDataTable(string procedureName, SqlParameter[] prmArray = null)
{
DataTable dt = new DataTable();
dt = null;
using (SqlConnection connection = new SqlConnection(Common.GetConnectionString()))
{
SqlCommand command = new SqlCommand();
SqlDataAdapter da = new SqlDataAdapter(command);
DataSet ds = new DataSet();
try
{
// attempt to open sql connection and exec command
connection.Open();
command.Connection = connection;
command.CommandText = procedureName;
command.CommandType = CommandType.StoredProcedure;
// add parameters to command if they exist
if (prmArray != null)
{
foreach (SqlParameter p in prmArray)
{
command.Parameters.AddWithValue(p.ParameterName, p.Value);
}
}
da.Fill(ds);
//Check whether there is table in dataset
if (ds != null )
{
if (ds.Tables.Count > 0)
{
dt = ds.Tables[0];
}
}
}
catch (SqlException exSql)
{
EventLogging.LogEvent("Exception", exSql.ToString());
dt = null;
}
catch (Exception ex)
{
EventLogging.LogEvent("Exception", ex.ToString());
dt = null;
}
finally
{
command.Dispose();
connection.Dispose();
}
}
return dt;
}
我的Typed DataSet下有3-4个不同的DataTables,我希望Helper函数适用于我所有类型的数据表。 如何将Typed DataTable作为输出参数传递给此函数? 我也怀疑,这可能吗?
答案 0 :(得分:1)
使方法通用。这样它就可以返回您输入的DataTable
。您应该在方法中添加DataTable, new()
约束。
public static T ExecuteProcedureReturnDataTable<T>(string procedureName, SqlParameter[] prmArray = null) where T : DataTable, new()
{
T dt = new T();
using (SqlConnection connection = new SqlConnection(Common.GetConnectionString()))
{
SqlCommand command = new SqlCommand();
SqlDataAdapter da = new SqlDataAdapter(command);
try
{
// attempt to open sql connection and exec command
connection.Open();
command.Connection = connection;
command.CommandText = procedureName;
command.CommandType = CommandType.StoredProcedure;
// add parameters to command if they exist
if (prmArray != null)
{
foreach (SqlParameter p in prmArray)
{
command.Parameters.AddWithValue(p.ParameterName, p.Value);
}
}
da.Fill(dt);
}
catch (SqlException exSql)
{
EventLogging.LogEvent("Exception", exSql.ToString());
dt = null;
}
catch (Exception ex)
{
EventLogging.LogEvent("Exception", ex.ToString());
dt = null;
}
finally
{
command.Dispose();
connection.Dispose();
}
}
return dt;
}
然后将其称为:
var table = ExecuteProcedureReturnDataTable<YourDataSet.YourTable>(...);