/// <summary>
/// 获取指定字段的聚合函数值
/// </summary>
/// <param name="fieldName">字段名</param>
/// <param name="condition">查询条件(不包含WHERE)</param>
/// <returns>总数</returns>
public virtual decimal GetAvgDecimal(string fieldName, string condition = null)
{
return(DbUtil.AggregateDecimal(DbHelper, CurrentTableName, fieldName, condition: condition, function: "AVG"));
}