NHibernate 联合查询,解决方法-通过自动转换成DataTable
1.单表查询用.AddEntity(),即可返回model类型.
ISession session = this._sessionManager.OpenSession();
IQuery query = session.CreateSQLQuery(sql).AddEntity("EntityName");
2.多表查询时,默认只能返回List 数据类型,然后通过 Object[] 来绑定值,这样带来了很多的不方便.
通过查询发现有2种方法,1.重写一个model 2.手动创建datatable.
发现重写比较麻烦,手动创建又太累.于是乎我把2种方法结合了一下:
1.在一个实体层中,添加另一个表中需要查询出来的字段,如下(红色字段)
1 namespace Equipment.Modules.API.Domain 2 { 3 //sb_sbinfo 4 public class sb_sbinfo 5 { 6 7 /// <summary> 8 /// id 9 /// </summary> 10 public virtual int id 11 { 12 get; 13 set; 14 } 15 /// <summary> 16 /// sb__id 17 /// </summary> 18 public virtual int? sb_id 19 { 20 get; 21 set; 22 } 23 /// <summary> 24 /// sbName 25 /// </summary> 26 public virtual string sbName 27 { 28 get; 29 set; 30 } 31 /// <summary> 32 /// sbCode 33 /// </summary> 34 public virtual int? sbCode 35 { 36 get; 37 set; 38 } 39 /// <summary> 40 /// sbType 41 /// </summary> 42 public virtual string sbType 43 { 44 get; 45 set; 46 } 47 /// <summary> 48 /// sbpp 49 /// </summary> 50 public virtual int? sbpp 51 { 52 get; 53 set; 54 } 55 /// <summary> 56 /// sbDj 57 /// </summary> 58 public virtual decimal? sbDj 59 { 60 get; 61 set; 62 } 63 /// <summary> 64 /// sbdw 65 /// </summary> 66 public virtual string sbdw 67 { 68 get; 69 set; 70 } 71 /// <summary> 72 /// sbggxhao 73 /// </summary> 74 public virtual string sbggxhao 75 { 76 get; 77 set; 78 } 79 /// <summary> 80 /// sbzjfs 81 /// </summary> 82 public virtual int? sbzjfs 83 { 84 get; 85 set; 86 } 87 /// <summary> 88 /// sbstatu 89 /// </summary> 90 public virtual int? sbstatu 91 { 92 get; 93 set; 94 } 95 /// <summary> 96 /// sbSccj 97 /// </summary> 98 public virtual string sbSccj 99 { 100 get; 101 set; 102 } 103 /// <summary> 104 /// sbCcTime 105 /// </summary> 106 public virtual DateTime? sbCcTime 107 { 108 get; 109 set; 110 } 111 /// <summary> 112 /// sbBuyTime 113 /// </summary> 114 public virtual DateTime? sbBuyTime 115 { 116 get; 117 set; 118 } 119 /// <summary> 120 /// sbYt 121 /// </summary> 122 public virtual string sbYt 123 { 124 get; 125 set; 126 } 127 /// <summary> 128 /// sbBzq 129 /// </summary> 130 public virtual string sbBzq 131 { 132 get; 133 set; 134 } 135 /// <summary> 136 /// sbly 137 /// </summary> 138 public virtual string sbly 139 { 140 get; 141 set; 142 } 143 /// <summary> 144 /// sbRkTime 145 /// </summary> 146 public virtual DateTime? sbRkTime 147 { 148 get; 149 set; 150 } 151 /// <summary> 152 /// sbRkry 153 /// </summary> 154 public virtual string sbRkry 155 { 156 get; 157 set; 158 } 159 /// <summary> 160 /// sbUptime 161 /// </summary> 162 public virtual DateTime? sbUptime 163 { 164 get; 165 set; 166 } 167 /// <summary> 168 /// t1 169 /// </summary> 170 public virtual string t1 171 { 172 get; 173 set; 174 } 175 /// <summary> 176 /// t2 177 /// </summary> 178 public virtual string t2 179 { 180 get; 181 set; 182 } 183 /// <summary> 184 /// t3 185 /// </summary> 186 public virtual string t3 187 { 188 get; 189 set; 190 } 191 /// <summary> 192 /// t4 193 /// </summary> 194 public virtual string t4 195 { 196 get; 197 set; 198 } 199 /// <summary> 200 /// t5 201 /// </summary> 202 public virtual string t5 203 { 204 get; 205 set; 206 } 207 208 /// <summary> 209 /// 在联合查询终另一个表终的id 210 /// </summary> 211 public virtual int ot_id 212 { 213 get; 214 set; 215 } 216 217 218 } 219 }
2.在执行SQL查询语句时,按上面实体的先后顺序写出查询语句,如(其中b.id是另一个表中的字段,转换成刚刚实体层中添加的字段):
SELECT ss.id, ss.sb_id, ss.sbName, ss.sbCode, ss.sbType, ss.sbpp, ss.sbDj, ss.sbdw,ss.sbggxhao, ss.sbzjfs, ss.sbstatu, ss.sbSccj, ss.sbCcTime, ss.sbBuyTime, ss.sbYt, ss.sbBzq, ss.sbly, ss.sbRkTime, ss.sbRkry, ss.sbUptime, ss.t1, ss.t2, ss.t3, ss.t4, ss.t5,b.id as ot_id From sb_sbinfo ss , sb_detailInfo b where ss.id=b.sbid
3.把查询出来的ILIST通过反射查询实体类中的字段,再转换成DATATABLE,最后返回一个DATATABLE.
ISession session = this._sessionManager.OpenSession(); IQuery query = session.CreateSQLQuery(sql); Assembly assembly = Assembly.Load("Equipment.Modules.API"); Type type = assembly.GetType("Equipment.Modules.API.Domain.sb_sbinfo"); PropertyInfo[] myPropertyInfo = type.GetProperties(BindingFlags.Public | BindingFlags.Instance); IList li = query.List(); DataTable dt= getPropertyInfo(myPropertyInfo, li); return dt;
自动生成DATAtable类如下:
public DataTable getPropertyInfo(PropertyInfo[] myPropertyInfo,IList li) { DataTable dt = new DataTable(); string propStr = ""; DataColumn column; DataRow row; // Display information for all properties. for (int j = 0 ; j < li.Count ; j++) { row = dt.NewRow(); for (int i = 0; i < myPropertyInfo.Length; i++) { PropertyInfo myPropInfo = (PropertyInfo)myPropertyInfo[i]; if (dt.Columns[myPropInfo.Name] == null) { if (myPropInfo.PropertyType.UnderlyingSystemType.ToString() == "System.Nullable`1[System.Int32]") { column = new DataColumn(myPropInfo.Name, typeof(Int32)); dt.Columns.Add(column); } else if (myPropInfo.PropertyType.UnderlyingSystemType.ToString() == "System.Nullable`1[System.Decimal]") { column = new DataColumn(myPropInfo.Name, typeof(Decimal)); dt.Columns.Add(column); } else if (myPropInfo.PropertyType.UnderlyingSystemType.ToString() == "System.Nullable`1[System.DateTime]") { column = new DataColumn(myPropInfo.Name, typeof(DateTime)); dt.Columns.Add(column); } else { column = new DataColumn(myPropInfo.Name, myPropInfo.PropertyType); dt.Columns.Add(column); } Object[] obj = (Object[])li[j]; //添加值 if (obj[i] != null) { row[myPropInfo.Name] = obj[i]; } else { row[myPropInfo.Name] = System.DBNull.Value; } } else { Object[] obj = (Object[])li[j]; //添加值 if (obj[i] != null) { row[myPropInfo.Name] = obj[i]; } else { row[myPropInfo.Name] = System.DBNull.Value; } } } dt.Rows.Add(row); } return dt; }
通过以上可以生成完美的DataTable，但是需要注意的是,实体类字段的顺序,必须保持和查询语句中的查询顺序一样..