MySQL数据库访问帮助类
1.项目添加引用官方MySQL动态库MySql.Data.dll
下载地址：MySql.Data.dll（也可以到官网下载动态库）
项目添加引用
2.web.config配置数据库连接字符串
1 <?xml version="1.0"?>
2 <configuration>
3 <appSettings>
4 <!-- 连接字符串是否加密 -->
5 <add key="ConStringEncrypt" value="false"/>
6 <!-- 数据库连接字符串,（如果采用加密方式，上面一项要设置为true；加密工具，可在官方下载，
7 如果使用明文这样server=127.0.0.1;database=.....,上面则设置为false。 -->
8 <add key="ConnectionString" value="server=127.0.0.1;database=BenXHCMS;uid=sa;pwd=jyf"/>
9 </appSettings>
10 </configuration>
3.数据库字符串读取类（多一个加密算法，可以自己添加）
1 public class PubConstant
2 {
3 /// <summary>
4 /// 获取连接字符串
5 /// </summary>
6 public static string ConnectionString
7 {
8 get
9 {
10 string _connectionString = ConfigurationManager.AppSettings["ConnectionString"];
11 string ConStringEncrypt = ConfigurationManager.AppSettings["ConStringEncrypt"];
12 if (ConStringEncrypt == "true")
13 {
14 _connectionString = DESEncrypt.Decrypt(_connectionString);
15 }
16 return _connectionString;
17 }
18 }
19
20 /// <summary>
21 /// 得到web.config里配置项的数据库连接字符串。
22 /// </summary>
23 /// <param name="configName"></param>
24 /// <returns></returns>
25 public static string GetConnectionString(string configName)
26 {
27 string connectionString = ConfigurationManager.AppSettings[configName];
28 string ConStringEncrypt = ConfigurationManager.AppSettings["ConStringEncrypt"];
29 if (ConStringEncrypt == "true")
30 {
31 connectionString = DESEncrypt.Decrypt(connectionString);
32 }
33 return connectionString;
34 }
35
36
37 }
4.MySQL数据库访问类--注意：对 MySql.Data.MySqlClient引用
1 using System;
2 using System.Collections;
3 using System.Collections.Specialized;
4 using System.Data;
5 using MySql.Data.MySqlClient;
6 using System.Configuration;
7 using System.Data.Common;
8 using System.Collections.Generic;
9 namespace Maticsoft.DBUtility
10 {
11 /// <summary>
12 /// 数据访问抽象基础类
13 /// Copyright (C) Maticsoft
14 /// </summary>
15 public abstract class DbHelperMySQL
16 {
17 //数据库连接字符串(web.config来配置)，可以动态更改connectionString支持多数据库.
18 public static string connectionString = PubConstant.ConnectionString;
19 public DbHelperMySQL()
20 {
21 }
22
23 #region 公用方法
24 /// <summary>
25 /// 得到最大值
26 /// </summary>
27 /// <param name="FieldName"></param>
28 /// <param name="TableName"></param>
29 /// <returns></returns>
30 public static int GetMaxID(string FieldName, string TableName)
31 {
32 string strsql = "select max(" + FieldName + ")+1 from " + TableName;
33 object obj = GetSingle(strsql);
34 if (obj == null)
35 {
36 return 1;
37 }
38 else
39 {
40 return int.Parse(obj.ToString());
41 }
42 }
43 /// <summary>
44 /// 是否存在
45 /// </summary>
46 /// <param name="strSql"></param>
47 /// <returns></returns>
48 public static bool Exists(string strSql)
49 {
50 object obj = GetSingle(strSql);
51 int cmdresult;
52 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
53 {
54 cmdresult = 0;
55 }
56 else
57 {
58 cmdresult = int.Parse(obj.ToString());
59 }
60 if (cmdresult == 0)
61 {
62 return false;
63 }
64 else
65 {
66 return true;
67 }
68 }
69 /// <summary>
70 /// 是否存在（基于MySqlParameter）
71 /// </summary>
72 /// <param name="strSql"></param>
73 /// <param name="cmdParms"></param>
74 /// <returns></returns>
75 public static bool Exists(string strSql, params MySqlParameter[] cmdParms)
76 {
77 object obj = GetSingle(strSql, cmdParms);
78 int cmdresult;
79 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
80 {
81 cmdresult = 0;
82 }
83 else
84 {
85 cmdresult = int.Parse(obj.ToString());
86 }
87 if (cmdresult == 0)
88 {
89 return false;
90 }
91 else
92 {
93 return true;
94 }
95 }
96 #endregion
97
98 #region 执行简单SQL语句
99
100 /// <summary>
101 /// 执行SQL语句，返回影响的记录数
102 /// </summary>
103 /// <param name="SQLString">SQL语句</param>
104 /// <returns>影响的记录数</returns>
105 public static int ExecuteSql(string SQLString)
106 {
107 using (MySqlConnection connection = new MySqlConnection(connectionString))
108 {
109 using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
110 {
111 try
112 {
113 connection.Open();
114 int rows = cmd.ExecuteNonQuery();
115 return rows;
116 }
117 catch (MySql.Data.MySqlClient.MySqlException e)
118 {
119 connection.Close();
120 throw e;
121 }
122 }
123 }
124 }
125
126 public static int ExecuteSqlByTime(string SQLString, int Times)
127 {
128 using (MySqlConnection connection = new MySqlConnection(connectionString))
129 {
130 using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
131 {
132 try
133 {
134 connection.Open();
135 cmd.CommandTimeout = Times;
136 int rows = cmd.ExecuteNonQuery();
137 return rows;
138 }
139 catch (MySql.Data.MySqlClient.MySqlException e)
140 {
141 connection.Close();
142 throw e;
143 }
144 }
145 }
146 }
147
148 /// <summary>
149 /// 执行MySql和Oracle滴混合事务
150 /// </summary>
151 /// <param name="list">SQL命令行列表</param>
152 /// <param name="oracleCmdSqlList">Oracle命令行列表</param>
153 /// <returns>执行结果 0-由于SQL造成事务失败 -1 由于Oracle造成事务失败 1-整体事务执行成功</returns>
154 public static int ExecuteSqlTran(List<CommandInfo> list, List<CommandInfo> oracleCmdSqlList)
155 {
156 using (MySqlConnection conn = new MySqlConnection(connectionString))
157 {
158 conn.Open();
159 MySqlCommand cmd = new MySqlCommand();
160 cmd.Connection = conn;
161 MySqlTransaction tx = conn.BeginTransaction();
162 cmd.Transaction = tx;
163 try
164 {
165 foreach (CommandInfo myDE in list)
166 {
167 string cmdText = myDE.CommandText;
168 MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
169 PrepareCommand(cmd, conn, tx, cmdText, cmdParms);
170 if (myDE.EffentNextType == EffentNextType.SolicitationEvent)
171 {
172 if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
173 {
174 tx.Rollback();
175 throw new Exception("违背要求"+myDE.CommandText+"必须符合select count(..的格式");
176 //return 0;
177 }
178
179 object obj = cmd.ExecuteScalar();
180 bool isHave = false;
181 if (obj == null && obj == DBNull.Value)
182 {
183 isHave = false;
184 }
185 isHave = Convert.ToInt32(obj) > 0;
186 if (isHave)
187 {
188 //引发事件
189 myDE.OnSolicitationEvent();
190 }
191 }
192 if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine)
193 {
194 if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
195 {
196 tx.Rollback();
197 throw new Exception("SQL:违背要求" + myDE.CommandText + "必须符合select count(..的格式");
198 //return 0;
199 }
200
201 object obj = cmd.ExecuteScalar();
202 bool isHave = false;
203 if (obj == null && obj == DBNull.Value)
204 {
205 isHave = false;
206 }
207 isHave = Convert.ToInt32(obj) > 0;
208
209 if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave)
210 {
211 tx.Rollback();
212 throw new Exception("SQL:违背要求" + myDE.CommandText + "返回值必须大于0");
213 //return 0;
214 }
215 if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave)
216 {
217 tx.Rollback();
218 throw new Exception("SQL:违背要求" + myDE.CommandText + "返回值必须等于0");
219 //return 0;
220 }
221 continue;
222 }
223 int val = cmd.ExecuteNonQuery();
224 if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0)
225 {
226 tx.Rollback();
227 throw new Exception("SQL:违背要求" + myDE.CommandText + "必须有影响行");
228 //return 0;
229 }
230 cmd.Parameters.Clear();
231 }
232 string oraConnectionString = PubConstant.GetConnectionString("ConnectionStringPPC");
233 bool res = OracleHelper.ExecuteSqlTran(oraConnectionString, oracleCmdSqlList);
234 if (!res)
235 {
236 tx.Rollback();
237 throw new Exception("执行失败");
238 // return -1;
239 }
240 tx.Commit();
241 return 1;
242 }
243 catch (MySql.Data.MySqlClient.MySqlException e)
244 {
245 tx.Rollback();
246 throw e;
247 }
248 catch (Exception e)
249 {
250 tx.Rollback();
251 throw e;
252 }
253 }
254 }
255 /// <summary>
256 /// 执行多条SQL语句，实现数据库事务。
257 /// </summary>
258 /// <param name="SQLStringList">多条SQL语句</param>
259 public static int ExecuteSqlTran(List<String> SQLStringList)
260 {
261 using (MySqlConnection conn = new MySqlConnection(connectionString))
262 {
263 conn.Open();
264 MySqlCommand cmd = new MySqlCommand();
265 cmd.Connection = conn;
266 MySqlTransaction tx = conn.BeginTransaction();
267 cmd.Transaction = tx;
268 try
269 {
270 int count = 0;
271 for (int n = 0; n < SQLStringList.Count; n++)
272 {
273 string strsql = SQLStringList[n];
274 if (strsql.Trim().Length > 1)
275 {
276 cmd.CommandText = strsql;
277 count += cmd.ExecuteNonQuery();
278 }
279 }
280 tx.Commit();
281 return count;
282 }
283 catch
284 {
285 tx.Rollback();
286 return 0;
287 }
288 }
289 }
290 /// <summary>
291 /// 执行带一个存储过程参数的的SQL语句。
292 /// </summary>
293 /// <param name="SQLString">SQL语句</param>
294 /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
295 /// <returns>影响的记录数</returns>
296 public static int ExecuteSql(string SQLString, string content)
297 {
298 using (MySqlConnection connection = new MySqlConnection(connectionString))
299 {
300 MySqlCommand cmd = new MySqlCommand(SQLString, connection);
301 MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
302 myParameter.Value = content;
303 cmd.Parameters.Add(myParameter);
304 try
305 {
306 connection.Open();
307 int rows = cmd.ExecuteNonQuery();
308 return rows;
309 }
310 catch (MySql.Data.MySqlClient.MySqlException e)
311 {
312 throw e;
313 }
314 finally
315 {
316 cmd.Dispose();
317 connection.Close();
318 }
319 }
320 }
321 /// <summary>
322 /// 执行带一个存储过程参数的的SQL语句。
323 /// </summary>
324 /// <param name="SQLString">SQL语句</param>
325 /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
326 /// <returns>影响的记录数</returns>
327 public static object ExecuteSqlGet(string SQLString, string content)
328 {
329 using (MySqlConnection connection = new MySqlConnection(connectionString))
330 {
331 MySqlCommand cmd = new MySqlCommand(SQLString, connection);
332 MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
333 myParameter.Value = content;
334 cmd.Parameters.Add(myParameter);
335 try
336 {
337 connection.Open();
338 object obj = cmd.ExecuteScalar();
339 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
340 {
341 return null;
342 }
343 else
344 {
345 return obj;
346 }
347 }
348 catch (MySql.Data.MySqlClient.MySqlException e)
349 {
350 throw e;
351 }
352 finally
353 {
354 cmd.Dispose();
355 connection.Close();
356 }
357 }
358 }
359 /// <summary>
360 /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
361 /// </summary>
362 /// <param name="strSQL">SQL语句</param>
363 /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
364 /// <returns>影响的记录数</returns>
365 public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
366 {
367 using (MySqlConnection connection = new MySqlConnection(connectionString))
368 {
369 MySqlCommand cmd = new MySqlCommand(strSQL, connection);
370 MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@fs", SqlDbType.Image);
371 myParameter.Value = fs;
372 cmd.Parameters.Add(myParameter);
373 try
374 {
375 connection.Open();
376 int rows = cmd.ExecuteNonQuery();
377 return rows;
378 }
379 catch (MySql.Data.MySqlClient.MySqlException e)
380 {
381 throw e;
382 }
383 finally
384 {
385 cmd.Dispose();
386 connection.Close();
387 }
388 }
389 }
390
391 /// <summary>
392 /// 执行一条计算查询结果语句，返回查询结果（object）。
393 /// </summary>
394 /// <param name="SQLString">计算查询结果语句</param>
395 /// <returns>查询结果（object）</returns>
396 public static object GetSingle(string SQLString)
397 {
398 using (MySqlConnection connection = new MySqlConnection(connectionString))
399 {
400 using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
401 {
402 try
403 {
404 connection.Open();
405 object obj = cmd.ExecuteScalar();
406 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
407 {
408 return null;
409 }
410 else
411 {
412 return obj;
413 }
414 }
415 catch (MySql.Data.MySqlClient.MySqlException e)
416 {
417 connection.Close();
418 throw e;
419 }
420 }
421 }
422 }
423 public static object GetSingle(string SQLString, int Times)
424 {
425 using (MySqlConnection connection = new MySqlConnection(connectionString))
426 {
427 using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
428 {
429 try
430 {
431 connection.Open();
432 cmd.CommandTimeout = Times;
433 object obj = cmd.ExecuteScalar();
434 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
435 {
436 return null;
437 }
438 else
439 {
440 return obj;
441 }
442 }
443 catch (MySql.Data.MySqlClient.MySqlException e)
444 {
445 connection.Close();
446 throw e;
447 }
448 }
449 }
450 }
451 /// <summary>
452 /// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader进行Close )
453 /// </summary>
454 /// <param name="strSQL">查询语句</param>
455 /// <returns>MySqlDataReader</returns>
456 public static MySqlDataReader ExecuteReader(string strSQL)
457 {
458 MySqlConnection connection = new MySqlConnection(connectionString);
459 MySqlCommand cmd = new MySqlCommand(strSQL, connection);
460 try
461 {
462 connection.Open();
463 MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
464 return myReader;
465 }
466 catch (MySql.Data.MySqlClient.MySqlException e)
467 {
468 throw e;
469 }
470
471 }
472 /// <summary>
473 /// 执行查询语句，返回DataSet
474 /// </summary>
475 /// <param name="SQLString">查询语句</param>
476 /// <returns>DataSet</returns>
477 public static DataSet Query(string SQLString)
478 {
479 using (MySqlConnection connection = new MySqlConnection(connectionString))
480 {
481 DataSet ds = new DataSet();
482 try
483 {
484 connection.Open();
485 MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
486 command.Fill(ds, "ds");
487 }
488 catch (MySql.Data.MySqlClient.MySqlException ex)
489 {
490 throw new Exception(ex.Message);
491 }
492 return ds;
493 }
494 }
495 public static DataSet Query(string SQLString, int Times)
496 {
497 using (MySqlConnection connection = new MySqlConnection(connectionString))
498 {
499 DataSet ds = new DataSet();
500 try
501 {
502 connection.Open();
503 MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
504 command.SelectCommand.CommandTimeout = Times;
505 command.Fill(ds, "ds");
506 }
507 catch (MySql.Data.MySqlClient.MySqlException ex)
508 {
509 throw new Exception(ex.Message);
510 }
511 return ds;
512 }
513 }
514
515
516
517 #endregion
518
519 #region 执行带参数的SQL语句
520
521 /// <summary>
522 /// 执行SQL语句，返回影响的记录数
523 /// </summary>
524 /// <param name="SQLString">SQL语句</param>
525 /// <returns>影响的记录数</returns>
526 public static int ExecuteSql(string SQLString, params MySqlParameter[] cmdParms)
527 {
528 using (MySqlConnection connection = new MySqlConnection(connectionString))
529 {
530 using (MySqlCommand cmd = new MySqlCommand())
531 {
532 try
533 {
534 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
535 int rows = cmd.ExecuteNonQuery();
536 cmd.Parameters.Clear();
537 return rows;
538 }
539 catch (MySql.Data.MySqlClient.MySqlException e)
540 {
541 throw e;
542 }
543 }
544 }
545 }
546
547
548 /// <summary>
549 /// 执行多条SQL语句，实现数据库事务。
550 /// </summary>
551 /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
552 public static void ExecuteSqlTran(Hashtable SQLStringList)
553 {
554 using (MySqlConnection conn = new MySqlConnection(connectionString))
555 {
556 conn.Open();
557 using (MySqlTransaction trans = conn.BeginTransaction())
558 {
559 MySqlCommand cmd = new MySqlCommand();
560 try
561 {
562 //循环
563 foreach (DictionaryEntry myDE in SQLStringList)
564 {
565 string cmdText = myDE.Key.ToString();
566 MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Value;
567 PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
568 int val = cmd.ExecuteNonQuery();
569 cmd.Parameters.Clear();
570 }
571 trans.Commit();
572 }
573 catch
574 {
575 trans.Rollback();
576 throw;
577 }
578 }
579 }
580 }
581 /// <summary>
582 /// 执行多条SQL语句，实现数据库事务。
583 /// </summary>
584 /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
585 public static int ExecuteSqlTran(System.Collections.Generic.List<CommandInfo> cmdList)
586 {
587 using (MySqlConnection conn = new MySqlConnection(connectionString))
588 {
589 conn.Open();
590 using (MySqlTransaction trans = conn.BeginTransaction())
591 {
592 MySqlCommand cmd = new MySqlCommand();
593 try
594 { int count = 0;
595 //循环
596 foreach (CommandInfo myDE in cmdList)
597 {
598 string cmdText = myDE.CommandText;
599 MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
600 PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
601
602 if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine)
603 {
604 if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
605 {
606 trans.Rollback();
607 return 0;
608 }
609
610 object obj = cmd.ExecuteScalar();
611 bool isHave = false;
612 if (obj == null && obj == DBNull.Value)
613 {
614 isHave = false;
615 }
616 isHave = Convert.ToInt32(obj) > 0;
617
618 if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave)
619 {
620 trans.Rollback();
621 return 0;
622 }
623 if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave)
624 {
625 trans.Rollback();
626 return 0;
627 }
628 continue;
629 }
630 int val = cmd.ExecuteNonQuery();
631 count += val;
632 if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0)
633 {
634 trans.Rollback();
635 return 0;
636 }
637 cmd.Parameters.Clear();
638 }
639 trans.Commit();
640 return count;
641 }
642 catch
643 {
644 trans.Rollback();
645 throw;
646 }
647 }
648 }
649 }
650 /// <summary>
651 /// 执行多条SQL语句，实现数据库事务。
652 /// </summary>
653 /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
654 public static void ExecuteSqlTranWithIndentity(System.Collections.Generic.List<CommandInfo> SQLStringList)
655 {
656 using (MySqlConnection conn = new MySqlConnection(connectionString))
657 {
658 conn.Open();
659 using (MySqlTransaction trans = conn.BeginTransaction())
660 {
661 MySqlCommand cmd = new MySqlCommand();
662 try
663 {
664 int indentity = 0;
665 //循环
666 foreach (CommandInfo myDE in SQLStringList)
667 {
668 string cmdText = myDE.CommandText;
669 MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
670 foreach (MySqlParameter q in cmdParms)
671 {
672 if (q.Direction == ParameterDirection.InputOutput)
673 {
674 q.Value = indentity;
675 }
676 }
677 PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
678 int val = cmd.ExecuteNonQuery();
679 foreach (MySqlParameter q in cmdParms)
680 {
681 if (q.Direction == ParameterDirection.Output)
682 {
683 indentity = Convert.ToInt32(q.Value);
684 }
685 }
686 cmd.Parameters.Clear();
687 }
688 trans.Commit();
689 }
690 catch
691 {
692 trans.Rollback();
693 throw;
694 }
695 }
696 }
697 }
698 /// <summary>
699 /// 执行多条SQL语句，实现数据库事务。
700 /// </summary>
701 /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
702 public static void ExecuteSqlTranWithIndentity(Hashtable SQLStringList)
703 {
704 using (MySqlConnection conn = new MySqlConnection(connectionString))
705 {
706 conn.Open();
707 using (MySqlTransaction trans = conn.BeginTransaction())
708 {
709 MySqlCommand cmd = new MySqlCommand();
710 try
711 {
712 int indentity = 0;
713 //循环
714 foreach (DictionaryEntry myDE in SQLStringList)
715 {
716 string cmdText = myDE.Key.ToString();
717 MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Value;
718 foreach (MySqlParameter q in cmdParms)
719 {
720 if (q.Direction == ParameterDirection.InputOutput)
721 {
722 q.Value = indentity;
723 }
724 }
725 PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
726 int val = cmd.ExecuteNonQuery();
727 foreach (MySqlParameter q in cmdParms)
728 {
729 if (q.Direction == ParameterDirection.Output)
730 {
731 indentity = Convert.ToInt32(q.Value);
732 }
733 }
734 cmd.Parameters.Clear();
735 }
736 trans.Commit();
737 }
738 catch
739 {
740 trans.Rollback();
741 throw;
742 }
743 }
744 }
745 }
746 /// <summary>
747 /// 执行一条计算查询结果语句，返回查询结果（object）。
748 /// </summary>
749 /// <param name="SQLString">计算查询结果语句</param>
750 /// <returns>查询结果（object）</returns>
751 public static object GetSingle(string SQLString, params MySqlParameter[] cmdParms)
752 {
753 using (MySqlConnection connection = new MySqlConnection(connectionString))
754 {
755 using (MySqlCommand cmd = new MySqlCommand())
756 {
757 try
758 {
759 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
760 object obj = cmd.ExecuteScalar();
761 cmd.Parameters.Clear();
762 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
763 {
764 return null;
765 }
766 else
767 {
768 return obj;
769 }
770 }
771 catch (MySql.Data.MySqlClient.MySqlException e)
772 {
773 throw e;
774 }
775 }
776 }
777 }
778
779 /// <summary>
780 /// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader进行Close )
781 /// </summary>
782 /// <param name="strSQL">查询语句</param>
783 /// <returns>MySqlDataReader</returns>
784 public static MySqlDataReader ExecuteReader(string SQLString, params MySqlParameter[] cmdParms)
785 {
786 MySqlConnection connection = new MySqlConnection(connectionString);
787 MySqlCommand cmd = new MySqlCommand();
788 try
789 {
790 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
791 MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
792 cmd.Parameters.Clear();
793 return myReader;
794 }
795 catch (MySql.Data.MySqlClient.MySqlException e)
796 {
797 throw e;
798 }
799 // finally
800 // {
801 // cmd.Dispose();
802 // connection.Close();
803 // }
804
805 }
806
807 /// <summary>
808 /// 执行查询语句，返回DataSet
809 /// </summary>
810 /// <param name="SQLString">查询语句</param>
811 /// <returns>DataSet</returns>
812 public static DataSet Query(string SQLString, params MySqlParameter[] cmdParms)
813 {
814 using (MySqlConnection connection = new MySqlConnection(connectionString))
815 {
816 MySqlCommand cmd = new MySqlCommand();
817 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
818 using (MySqlDataAdapter da = new MySqlDataAdapter(cmd))
819 {
820 DataSet ds = new DataSet();
821 try
822 {
823 da.Fill(ds, "ds");
824 cmd.Parameters.Clear();
825 }
826 catch (MySql.Data.MySqlClient.MySqlException ex)
827 {
828 throw new Exception(ex.Message);
829 }
830 return ds;
831 }
832 }
833 }
834
835
836 private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, string cmdText, MySqlParameter[] cmdParms)
837 {
838 if (conn.State != ConnectionState.Open)
839 conn.Open();
840 cmd.Connection = conn;
841 cmd.CommandText = cmdText;
842 if (trans != null)
843 cmd.Transaction = trans;
844 cmd.CommandType = CommandType.Text;//cmdType;
845 if (cmdParms != null)
846 {
847
848
849 foreach (MySqlParameter parameter in cmdParms)
850 {
851 if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
852 (parameter.Value == null))
853 {
854 parameter.Value = DBNull.Value;
855 }
856 cmd.Parameters.Add(parameter);
857 }
858 }
859 }
860
861 #endregion
862
863
864
865 }
866
867 }