「Unity/Csharp/linq」の版間の差分
提供: 初心者エンジニアの簡易メモ
(→sum) |
(→数値の合計) |
||
行56: | 行56: | ||
List<Score> scores = FindAll(); | List<Score> scores = FindAll(); | ||
return scores.Sum(record => record.missCnt); | return scores.Sum(record => record.missCnt); | ||
+ | |||
+ | ==like前方一致== | ||
+ | List<Score> scores = FindAll(); | ||
+ | List<Score> scores = scores.Where(record => record.yyyymmdd.StartsWith("201903")); | ||
+ | |||
+ | ==like後方一致== | ||
+ | List<Score> scores = FindAll(); | ||
+ | List<Score> scores = scores.Where(record => record.yyyymmdd.EndsWith("0316")); |
2019年3月14日 (木) 02:49時点における版
目次
準備
using System.Linq;
条件一行だけ(fetchRow)
public ScoreDay FindRowByYyyymmdd(string yyyymmdd) { List<ScoreDay> scores = FindAll(); return scores.FirstOrDefault(score => score.yyyymmdd == yyyymmdd); }
条件複数行(fetchAll)
public IEnumerable<ScoreDay> FindAllByYyyymmdd(string yyyymmdd) { List<ScoreDay> scores = FindAll(); return scores.Where(score => score.yyyymmdd == yyyymmdd); }
順序
User[] users = new User[] { new User() { age = 10, name = "taro" }, new User() { age = 13, name = "jiro" }, new User() { age = 12, name = "saburo" }, new User() { age = 15, name = "siro" }, }; // 年下順 IOrderedEnumerable<Parameter> orderedUsers = users.OrderBy( value => value.age ); // 年上順 IOrderedEnumerable<Parameter> orderedUsers = users.OrderByDescending( value => value.age );
取得件数を絞る
List<Score> scores = new List<Score>(); IEnumerable<Score> tmpScores = scores.Skip(0).Take(100);
指定条件だけに絞る
List<ScoreDay> scores = FindAll(); IEnumerable<Score> tmpScores = scores.Where(score => score.sec > 6); List<Score> scores = tmpScores.ToList();
IEnumerableをListへ変換
IEnumerable<Score> tmpScores = // 略・・・ List<Score> scores = tmpScores.ToList());
数値の合計
List<Score> scores = FindAll(); return scores.Sum(record => record.missCnt);
like前方一致
List<Score> scores = FindAll(); List<Score> scores = scores.Where(record => record.yyyymmdd.StartsWith("201903"));
like後方一致
List<Score> scores = FindAll(); List<Score> scores = scores.Where(record => record.yyyymmdd.EndsWith("0316"));