首先定义一个静态类
1 public static class QueryAssembly
2 {
3 /// <summary>
4 /// 返回true
5 /// </summary>
6 /// <typeparam name="T"></typeparam>
7 /// <returns></returns>
8 public static Expression<Func<T, bool>> True<T>()
9 {
10 return f => true;
11 }
12
13 /// <summary>
14 /// false
15 /// </summary>
16 /// <typeparam name="T"></typeparam>
17 /// <returns></returns>
18 public static Expression<Func<T, bool>> False<T>()
19 {
20 return f => false;
21 }
22
23 /// <summary>
24 /// or
25 /// </summary>
26 /// <typeparam name="T"></typeparam>
27 /// <param name="expr1"></param>
28 /// <param name="expr2"></param>
29 /// <returns></returns>
30 public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> expr1,Expression<Func<T, bool>> expr2)
31 {
32 var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
33 return Expression.Lambda<Func<T, bool>>
34 (Expression.Or(expr1.Body, invokedExpr), expr1.Parameters);
35 }
36
37 /// <summary>
38 /// and
39 /// </summary>
40 /// <typeparam name="T"></typeparam>
41 /// <param name="expr1"></param>
42 /// <param name="expr2"></param>
43 /// <returns></returns>
44 public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expr1,Expression<Func<T, bool>> expr2)
45 {
46 var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
47 return Expression.Lambda<Func<T, bool>>
48 (Expression.And(expr1.Body, invokedExpr), expr1.Parameters);
49 }
50 }
定义Page类
1 public class Paging<T>
2 {
3 /// <summary>
4 /// 当前页码
5 /// </summary>
6 [DataMember]
7 public int PageNo { get; set; }
8
9 /// <summary>
10 /// 总页数
11 /// </summary>
12 [DataMember]
13 public int PageCount { get; set; }
14
15 /// <summary>
16 /// 每页记录数
17 /// </summary>
18 [DataMember]
19 public int PageSize { get; set; }
20
21 /// <summary>
22 /// 总记录数
23 /// </summary>
24 [DataMember]
25 public int RecordCount { get; set; }
26
27 /// <summary>
28 /// 当前页的数据
29 /// </summary>
30 [DataMember]
31 public List<T> CurrentList { get; set; }
32 }
查询方法
1 public Paging<DAML> QueryAJML(int pageNo, int pageSize,DAML data)
2 {
3 Paging<DAML> result = null;
4 Expression<Func<DAML, bool>> ExpWhere = QueryAssembly.True<DAML>();
5 using (IStatelessSession session = _sessionFactory.OpenStatelessSession())
6 {
7 var queryDAML = session.Query<DAML>();
8
9 if (!string.IsNullOrEmpty(data.MLH))
10 {
11 ExpWhere=ExpWhere.Or(x=>x.MLH.Contains(data.MLH));
12 }
13
14 if (!string.IsNullOrEmpty(data.QZH))
15 {
16 ExpWhere = ExpWhere.Or(x => x.MLH.Contains(data.QZH));
17 }
18
19 //查询
20 queryDAML.Where(ExpWhere);
21
22 //排序
23 queryDAML.OrderBy(x=>x.ID);
24
25 //页数
26 result.PageNo = pageNo;
27 //每页记录数
28 result.PageSize = pageSize;
29 //总记录数
30 result.RecordCount = queryDAML.Count();
31 //总页数
32 result.PageCount = (result.RecordCount + result.PageSize - 1) / result.PageSize;
33 //返回数据
34 result.CurrentList = new List<DAML>();
35 result.CurrentList = queryDAML.ToList();
36 }
37 return result;
38 }