/// <summary>
/// 创建判断是否非空的Sql条件语句
/// </summary>
/// <param name="columnName">字段名</param>
/// <returns>Sql条件语句</returns>
public static SqlBasicParameterCondition IsNotNull(String columnName)
{
return(SqlCondition.IsNotNull(SqlParameter.Create(columnName, null)));
}