/// <summary>
/// 执行SQL语句
/// </summary>
/// <param name="sql">SQL</param>
public DataSet ExecSql(string sql)
{
DataSet result = new DataSet();
using (_DbHelper conn = new _DbHelper(_conn))
{
conn.Open();
try { result = conn.ExecuteDataSet(sql); }
catch (Exception err) { throw err; }
finally { conn.Close(); }
}
return result;
}