1 using System;
2 using System.Collections.Generic;
3 using System.Data.Entity;
4 using System.Linq;
5
6 namespace WebHub {
7 public abstract class HubContext<DB, T>
8 where DB : DbContext, new()
9 where T : class {
10 public static void Remove(object idOrObj) {
11 using (var db = new DB()) {
12 if (idOrObj.GetType() == typeof(T)) {
13 db.Set<T>().Remove(idOrObj as T);
14 db.SaveChanges();
15 } else {
16 var t = db.Set<T>().Find(idOrObj);
17 db.Set<T>().Remove(t);
18 db.SaveChanges();
19 }
20 }
21 }
22 public static T Add(T t) {
23 using (var db = new DB()) {
24 db.Set<T>().Add(t);
25 db.SaveChanges();
26 return t;
27 }
28 }
29 public static T Add(T t, Action failCallback) {
30 using (var db = new DB()) {
31 db.Set<T>().Add(t);
32 try {
33 db.SaveChanges();
34 } catch (Exception) {
35 failCallback();
36 return default(T);
37 }
38 return t;
39 }
40 }
41 public static TR Execute<TR>(object id, Func<T, TR> func) {
42 var props = typeof(T).GetProperties();
43 using (var db = new DB()) {
44 var t = db.Set<T>().Find(id);
45 if (t == null) {
46 return default(TR);
47 }//TODO:if no "ToList()" below, won't work.WHY?
48 var oldValues = props.Select(p => p.GetValue(t, null) ?? string.Empty).ToList();
49 TR r;
50 try {
51 r = func(t);
52 } catch {
53 return default(TR);
54 }
55 var newValues = props.Select(p => p.GetValue(t, null) ?? string.Empty).ToList();
56
57 for (int i = 0; i < props.Count(); i++) {
58 if (newValues[i].GetHashCode() != oldValues[i].GetHashCode()) {
59 db.SaveChanges();
60 }
61 }
62 return r;
63 }
64 }
65
66 public static int Execute(object id, Action<T> action) {
67 var props = typeof(T).GetProperties();
68 using (var db = new DB()) {
69 var t = db.Set<T>().Find(id);
70 if (t == null) {
71 return 0;
72 }
73 var oldValues = props.Select(p => p.GetValue(t, null) ?? string.Empty).ToList();
74 try {
75 action(t);
76 } catch {
77 return 0;
78 }
79 var newValues = props.Select(p => p.GetValue(t, null) ?? string.Empty).ToList();
80 for (int i = 0; i < props.Count(); i++) {
81 if (newValues[i].GetHashCode() != oldValues[i].GetHashCode()) {
82 var r = db.SaveChanges();
83 return r;
84 }
85 }
86 return 0;
87 }
88 }
89 public static T First() {
90 using (var db = new DB()) {
91 var r = db.Set<T>().FirstOrDefault();
92 return r;
93 }
94 }
95 public static T First(object id) {
96 using (var db = new DB()) {
97 return db.Set<T>().Find(id);
98 }
99 }
100 public static T First(Func<T, bool> predicate) {
101 using (var db = new DB()) {
102 var r = db.Set<T>().FirstOrDefault(predicate);
103 return r;
104 }
105 }
106 public static T First<P>(Func<T, bool> predicate, Func<T, P> orderby) {
107 var r = First(predicate, orderby, false);
108 return r;
109 }
110 public static T First<P>(Func<T, bool> predicate, Func<T, P> orderby, bool desc) {
111 using (var db = new DB()) {
112 T r;
113 if (desc) {
114 r = db.Set<T>().Where(predicate).OrderByDescending(orderby).FirstOrDefault();
115 } else {
116 r = db.Set<T>().Where(predicate).OrderBy(orderby).FirstOrDefault();
117 }
118 return r;
119 }
120 }
121 public static int Count() {
122 using (var db = new DB()) {
123 return db.Set<T>().Count();
124 }
125 }
126 public static int Count(Func<T, bool> prediacate) {
127 using (var db = new DB()) {
128 return db.Set<T>().Count(prediacate);
129 }
130 }
131 public static IEnumerable<T> All() {
132 using (var db = new DB()) {
133 var r = db.Set<T>().ToList();
134 return r;
135 }
136 }
137 public static bool Exists(object id) {
138 using (var db = new DB()) {
139 var r = db.Set<T>().Find(id);
140 return r != null;
141 }
142 }
143 public static bool Exists(Func<T, bool> where) {
144 using (var db = new DB()) {
145 var r = db.Set<T>().Any(where);
146 return r;
147 }
148 }
149 public static IEnumerable<T> Find(Func<T, bool> where) {
150 using (var db = new DB()) {
151 var rr = db.Set<T>().Where(where).ToList();
152 return rr;
153 }
154 }
155 public static IEnumerable<T> Find<P>(Func<T, bool> where, Func<T, P> orderby) {
156 using (var db = new DB()) {
157 var r = db.Set<T>().Where(where).OrderBy(orderby).ToList();
158 return r;
159 }
160 }
161 public static IEnumerable<T> Find(Func<T, bool> where, int skip, int take) {
162 using (var db = new DB()) {
163 return db.Set<T>().Where(where).Skip(skip).Take(take).ToList();
164 }
165 }
166 public static IEnumerable<T> Find(Func<T, bool> where, int skip, int take, out int all) {
167 using (var db = new DB()) {
168 all = db.Set<T>().Count(where);
169 return db.Set<T>().Where(where).Skip(skip).Take(take).ToList();
170 }
171 }
172 public static IEnumerable<T> Find<P>(Func<T, bool> where, Func<T, P> orderby, int skip, int take) {
173 using (var db = new DB()) {
174 var r = db.Set<T>().Where(where).OrderBy(orderby).Skip(skip).Take(take).ToList();
175 return r;
176 }
177 }
178 public static IEnumerable<T> Find<P>(Func<T, bool> where, Func<T, P> orderby, int skip, int take, out int all) {
179 using (var db = new DB()) {
180 all = db.Set<T>().Count(where);
181 var r = db.Set<T>().Where(where).OrderBy(orderby).Skip(skip).Take(take).ToList();
182 return r;
183 }
184 }
185 public static IEnumerable<T> Find<P>(Func<T, bool> where, Func<T, P> orderby, DataPager p) {
186 using (var db = new DB()) {
187 p.Total = db.Set<T>().Count(where);
188 var r = db.Set<T>().Where(where).OrderBy(orderby).Skip(p.Current * p.Size).Take(p.Size).ToList();
189 return r;
190 }
191 }
192 }
193 }
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