Question

我有这样的DataTable：

 |inflation|budget   |reserve
1|decrease |no_change|increase
2|decrease |increase |decrease
3|no_change|increase |increase
4|no_change|increase |decrease
5|no_change|no_change|decrease
6|no_change|increase |no_change
7|decrease |increase |increase
8|no_change|no_change|increase

和行号列表：1, 2, 4, 5, 7。

我想获得包含在行号列表中的所有不同值。结果应如下所示：

    inflation-decrease { 1, 2, 7 }
    inflation-no_change { 3, 4, 5, 6, 8 }
    budget-no_change { 1, 5, 8 }
    budget-increase { 2, 3, 4, 6, 7 }
    reserve-increase { 1, 3, 7, 8 }
    reserve-decrease { 2, 4, 5 }

有更好的方法来实现使用Linq而不是循环遍历列，然后循环遍历行？数据可能会发生变化，因此我不能依赖列名。

修改我对这个问题的解决方案是：

    public class Rule
    {
        public String atribute { get; set; }
        public String value { get; set; }

        public Rule() { }

        public Rule(String atribute, String value)
        {
            this.atribute = atribute;
            this.value = value;
        }

        public override string ToString()
        {
            return atribute + "-" + value;
        }
    }

    public class RuleObject
    {
        public Rule rule { get; set; }
        public List<int> indexList { get; set; }

        public RuleObject() { }

        public RuleObject(Rule rule, List<int> indexList)
        {
            this.rule = rule;
            this.indexList = indexList;
        }

        public override string ToString()
        {
            return rule.ToString() + " { " + string.Join(",", indexList.ToArray()) + " }"; 
        }
    }

    public static class Program
    {
        public static void Main()
        {
            DataTable dataTable = new DataTable();
            dataTable.Columns.Add("inflation");
            dataTable.Columns.Add("budget");
            dataTable.Columns.Add("reserve");

            dataTable.Rows.Add("", "", ""); //dirty solution to start count row number from 1
            dataTable.Rows.Add("decrease", "no_change", "increase");
            dataTable.Rows.Add("decrease", "increase", "decrease");
            dataTable.Rows.Add("no_change", "increase", "increase");
            dataTable.Rows.Add("no_change", "increase", "decrease");
            dataTable.Rows.Add("no_change", "no_change", "decrease");
            dataTable.Rows.Add("no_change", "increase", "no_change");
            dataTable.Rows.Add("decrease", "increase", "increase");
            dataTable.Rows.Add("no_change", "no_change", "increase");

            List<int> rowNumbersList = new List<int>() { 1, 2, 4, 5, 7 };

            foreach (DataColumn dataColumn in dataTable.Columns)
            {
                var distinct = (from row in dataTable.AsEnumerable()
                                select new
                                {
                                    atribute = dataColumn.ColumnName,
                                    value = row.Field<string>(dataColumn.ColumnName),
                                    index = dataTable.Rows.IndexOf(row)
                                }
                                ).GroupBy(x => x.value)
                                 .Select(g => new RuleObject()
                                 {
                                     rule = new Rule(g.Select(h => h.atribute).First(), g.Key),
                                     indexList = g.Select(h => h.index).ToList()
                                 }
                                 ).Where(x => rowNumbersList.Intersect(x.indexList).Any());
                foreach (var d in distinct)
                {
                    Console.WriteLine(d.ToString());
                }
            }
        }
    }

您对此解决方案有何看法？

来自DataTable的不同数据 - 使用Linq返回列名，行值和数字

0 个答案: