public static class TeraDataHelper
{
//<add key="CommandTimeout" value="200000" />
//<add key="Teradata_Connect_String" value="Data Source = 172.20.70.73;User ID = pu_dw_user_web;Password = pu_dw_user_web;"/>
public static string TDConnstring = ConfigurationManager.ConnectionStrings["Teradata_Connect_String"].ConnectionString;
public static int CommandTimeout = int.Parse(ConfigurationManager.AppSettings["CommandTimeout"]);
/// <summary>
/// TD中查询sql
/// </summary>
/// <param name="sqlstr">sql语句</param>
/// <returns>返回DataRow</returns>
public static DataSet GetRows(string sqlString)
{
DataSet ds = new DataSet();
try
{
TdDataAdapter adapter = new TdDataAdapter(sqlString, TDConnstring);
adapter.Fill(ds);
}
catch (Exception ex)
{
//log.writeLog("执行sql 报错,报错信息为：" + ex.Message + ", 报错语句为：‘" + sqlString + "’", "失败");
//MessageBox.Show(ex.Message);
//throw;
}
return ds;
}
/// <summary>
/// 获取TD的数据
/// </summary>
/// <param name="sqlstr">sql语句：查询语句</param>
/// <returns>返回数据表 DataTable</returns>
public static DataTable GetTable(string sqlStr)
{
TdConnection con = new TdConnection();
DataTable dataTable = new DataTable();
con.ConnectionString = TDConnstring;
try
{
TdCommand cmd = con.CreateCommand();
cmd.CommandTimeout = CommandTimeout;
cmd.CommandText = sqlStr;
// Create the TdDataAdapter object. It retrieves the data from database and fill a single data table
// with in a dataset. It also capable of reconciling the changes to database.
TdDataAdapter adapter = new TdDataAdapter();
adapter.ReturnProviderSpecificTypes = true;
adapter.SelectCommand = cmd;
// Create a DataTable object and it represents one table of in-memory data.
adapter.ReturnProviderSpecificTypes = true;
adapter.Fill(dataTable);
return dataTable;
}
catch (Exception ex)
{
//log.writeLog("执行sql 报错,报错信息为：" + ex.Message + ", 报错语句为：‘" + sqlStr + "’", "失败");
//MessageBox.Show(ex.Message);
throw;
}
finally
{
if (con.State == ConnectionState.Open)
{
con.Close();
}
}
}
public static void ExecuteDataReader(string sql, Action<TdDataReader> action)
{
using (var connection = new TdConnection(TDConnstring))
{
connection.Open();
using (var cmd = connection.CreateCommand())
{
cmd.CommandText = sql;
using (var dr = cmd.ExecuteReader())
{
while (dr.Read())
action.Invoke(dr);
}
}
}
}
public static async void ExecuteDataReaderAsync(string sql, Action<TdDataReader> action)
{
using (var connection = new TdConnection(TDConnstring))
{
await connection.OpenAsync();
using (var cmd = connection.CreateCommand())
{
cmd.CommandText = sql;
var dr = await cmd.ExecuteReaderAsync( CommandBehavior.CloseConnection);
while (await dr.ReadAsync())
action.Invoke(dr);
}
}
}
public static IEnumerable<T> ExecuteDataReader<T>(string sql, Func<TdDataReader, T> action)
{
using (var connection = new TdConnection(TDConnstring))
{
connection.Open();
using (var cmd = connection.CreateCommand())
{
cmd.CommandText = sql;
using (var dr = cmd.ExecuteReader())
{
while (dr.Read())
yield return action.Invoke(dr);
}
}
}
}
public static async Task<IEnumerable<T>> ExecuteDataReaderAsync<T>(string sql, Func<TdDataReader, T> action)
{
using (var connection = new TdConnection(TDConnstring))
{
await connection.OpenAsync();
using (var cmd = connection.CreateCommand())
{
cmd.CommandText = sql;
using (var dr = await cmd.ExecuteReaderAsync())
{
return dr.Select(r => action(r)).ToList();
}
}
}
}
}
public static class Extensions
{
public static IEnumerable<T> Select<T>(
this TdDataReader reader, Func<TdDataReader, T> action)
{
while (reader.Read())
{
yield return action(reader);
}
}
}
