在vs里面连接数据库的方法有很多，这里是通用的方法和基本操作
SQL
1 /// <summary>
2 /// 数据访问抽象基础类
3 /// Copyright (C) Maticsoft
4 /// </summary>
5 public abstract class DbHelperSQL
6 {
7 public static int DataType = 1;
8 //数据库连接字符串(web.config来配置)，多数据库可使用DbHelperSQLP来实现.
9 public static string connectionString = ConfigurationManager.ConnectionStrings["ReadContext"].ConnectionString;
10 public DbHelperSQL()
11 {
12 if(DataType==2)
13 connectionString = ConfigurationManager.ConnectionStrings["ReadContextMySql"].ConnectionString;
14 }
15
16 #region 公用方法
17 /// <summary>
18 /// 判断是否存在某表的某个字段
19 /// </summary>
20 /// <param name="tableName">表名称</param>
21 /// <param name="columnName">列名称</param>
22 /// <returns>是否存在</returns>
23 public static bool ColumnExists(string tableName, string columnName)
24 {
25 string sql = "select count(1) from syscolumns where [id]=object_id('" + tableName + "') and [name]='" + columnName + "'";
26 object res = GetSingle(sql);
27 if (res == null)
28 {
29 return false;
30 }
31 return Convert.ToInt32(res) > 0;
32 }
33 public static int GetMaxID(string FieldName, string TableName)
34 {
35 string strsql = "select max(" + FieldName + ")+1 from " + TableName;
36 object obj = GetSingle(strsql);
37 if (obj == null)
38 {
39 return 1;
40 }
41 else
42 {
43 return int.Parse(obj.ToString());
44 }
45 }
46 public static bool Exists(string strSql)
47 {
48 object obj = GetSingle(strSql);
49 return ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) ? false : true;
50 }
51 /// <summary>
52 /// 表是否存在
53 /// </summary>
54 /// <param name="TableName"></param>
55 /// <returns></returns>
56 public static bool TabExists(string TableName)
57 {
58 string strsql = "select count(*) from sysobjects where id = object_id(N'[" + TableName + "]') and OBJECTPROPERTY(id, N'IsUserTable') = 1";
59 //string strsql = "SELECT count(*) FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[" + TableName + "]') AND type in (N'U')";
60 object obj = GetSingle(strsql);
61 int cmdresult;
62 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
63 {
64 cmdresult = 0;
65 }
66 else
67 {
68 cmdresult = int.Parse(obj.ToString());
69 }
70 if (cmdresult == 0)
71 {
72 return false;
73 }
74 else
75 {
76 return true;
77 }
78 }
79 public static bool Exists(string strSql, params SqlParameter[] cmdParms)
80 {
81 object obj = GetSingle(strSql, cmdParms);
82 int cmdresult;
83 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
84 {
85 cmdresult = 0;
86 }
87 else
88 {
89 cmdresult = int.Parse(obj.ToString());
90 }
91 if (cmdresult == 0)
92 {
93 return false;
94 }
95 else
96 {
97 return true;
98 }
99 }
100 #endregion
101
102 #region 执行简单SQL语句
103
104 /// <summary>
105 /// 执行SQL语句，返回影响的记录数
106 /// </summary>
107 /// <param name="SQLString">SQL语句</param>
108 /// <returns>影响的记录数</returns>
109 public static int ExecuteSql(string SQLString)
110 {
111 using (SqlConnection connection = new SqlConnection(connectionString))
112 {
113 using (SqlCommand cmd = new SqlCommand(SQLString, connection))
114 {
115 try
116 {
117 connection.Open();
118 int rows = cmd.ExecuteNonQuery();
119 return rows;
120 }
121 catch (System.Data.SqlClient.SqlException e)
122 {
123
124 connection.Close();
125 throw e;
126 }
127 }
128 }
129 }
130
131 public static int ExecuteSqlByTime(string SQLString, int Times)
132 {
133 using (SqlConnection connection = new SqlConnection(connectionString))
134 {
135 using (SqlCommand cmd = new SqlCommand(SQLString, connection))
136 {
137 try
138 {
139 connection.Open();
140 cmd.CommandTimeout = Times;
141 int rows = cmd.ExecuteNonQuery();
142 return rows;
143 }
144 catch (System.Data.SqlClient.SqlException e)
145 {
146
147 connection.Close();
148 throw e;
149 }
150 }
151 }
152 }
153 /// <summary>
154 /// 执行多条SQL语句，实现数据库事务。
155 /// </summary>
156 /// <param name="SQLStringList">多条SQL语句</param>
157 public static int ExecuteSqlTran(List<String> SQLStringList)
158 {
159 using (SqlConnection conn = new SqlConnection(connectionString))
160 {
161 conn.Open();
162 SqlCommand cmd = new SqlCommand();
163 cmd.Connection = conn;
164 SqlTransaction tx = conn.BeginTransaction();
165 cmd.Transaction = tx;
166 try
167 {
168 int count = 0;
169 for (int n = 0; n < SQLStringList.Count; n++)
170 {
171 string strsql = SQLStringList[n];
172 if (strsql.Trim().Length > 1)
173 {
174 cmd.CommandText = strsql;
175 count += cmd.ExecuteNonQuery();
176 }
177 }
178 tx.Commit();
179 return count;
180 }
181 catch(Exception e)
182 {
183 tx.Rollback();
184 return 0;
185 }
186 }
187 }
188 /// <summary>
189 /// 执行带一个存储过程参数的的SQL语句。
190 /// </summary>
191 /// <param name="SQLString">SQL语句</param>
192 /// <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>
193 /// <returns>影响的记录数</returns>
194 public static int ExecuteSql(string SQLString, string content)
195 {
196 using (SqlConnection connection = new SqlConnection(connectionString))
197 {
198 SqlCommand cmd = new SqlCommand(SQLString, connection);
199 System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText);
200 myParameter.Value = content;
201 cmd.Parameters.Add(myParameter);
202 try
203 {
204 connection.Open();
205 int rows = cmd.ExecuteNonQuery();
206 return rows;
207 }
208 catch (System.Data.SqlClient.SqlException e)
209 {
210
211 throw e;
212 }
213 finally
214 {
215 cmd.Dispose();
216 connection.Close();
217 }
218 }
219 }
220 /// <summary>
221 /// 执行带一个存储过程参数的的SQL语句。
222 /// </summary>
223 /// <param name="SQLString">SQL语句</param>
224 /// <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>
225 /// <returns>影响的记录数</returns>
226 public static object ExecuteSqlGet(string SQLString, string content)
227 {
228 using (SqlConnection connection = new SqlConnection(connectionString))
229 {
230 SqlCommand cmd = new SqlCommand(SQLString, connection);
231 System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.NText);
232 myParameter.Value = content;
233 cmd.Parameters.Add(myParameter);
234 try
235 {
236 connection.Open();
237 object obj = cmd.ExecuteScalar();
238 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
239 {
240 return null;
241 }
242 else
243 {
244 return obj;
245 }
246 }
247 catch (System.Data.SqlClient.SqlException e)
248 {
249
250 throw e;
251 }
252 finally
253 {
254 cmd.Dispose();
255 connection.Close();
256 }
257 }
258 }
259 /// <summary>
260 /// 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)
261 /// </summary>
262 /// <param name="strSQL">SQL语句</param>
263 /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
264 /// <returns>影响的记录数</returns>
265 public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
266 {
267 using (SqlConnection connection = new SqlConnection(connectionString))
268 {
269 SqlCommand cmd = new SqlCommand(strSQL, connection);
270 System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@fs", SqlDbType.Image);
271 myParameter.Value = fs;
272 cmd.Parameters.Add(myParameter);
273 try
274 {
275 connection.Open();
276 int rows = cmd.ExecuteNonQuery();
277 return rows;
278 }
279 catch (System.Data.SqlClient.SqlException e)
280 {
281
282 throw e;
283 }
284 finally
285 {
286 cmd.Dispose();
287 connection.Close();
288 }
289 }
290 }
291
292 /// <summary>
293 /// 执行一条计算查询结果语句，返回查询结果（object）。
294 /// </summary>
295 /// <param name="SQLString">计算查询结果语句</param>
296 /// <returns>查询结果（object）</returns>
297 public static object GetSingle(string SQLString)
298 {
299 using (SqlConnection connection = new SqlConnection(connectionString))
300 {
301 using (SqlCommand cmd = new SqlCommand(SQLString, connection))
302 {
303 try
304 {
305 connection.Open();
306 object obj = cmd.ExecuteScalar();
307 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
308 {
309 return null;
310 }
311 else
312 {
313 return obj;
314 }
315 }
316 catch (System.Data.SqlClient.SqlException e)
317 {
318
319 connection.Close();
320 throw e;
321 }
322 }
323 }
324 }
325 public static object GetSingle(string SQLString, int Times)
326 {
327 using (SqlConnection connection = new SqlConnection(connectionString))
328 {
329 using (SqlCommand cmd = new SqlCommand(SQLString, connection))
330 {
331 try
332 {
333 connection.Open();
334 cmd.CommandTimeout = Times;
335 object obj = cmd.ExecuteScalar();
336 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
337 {
338 return null;
339 }
340 else
341 {
342 return obj;
343 }
344 }
345 catch (System.Data.SqlClient.SqlException e)
346 {
347
348 connection.Close();
349 throw e;
350 }
351 }
352 }
353 }
354 /// <summary>
355 /// 执行查询语句，返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
356 /// </summary>
357 /// <param name="strSQL">查询语句</param>
358 /// <returns>SqlDataReader</returns>
359 public static SqlDataReader ExecuteReader(string strSQL)
360 {
361 SqlConnection connection = new SqlConnection(connectionString);
362 SqlCommand cmd = new SqlCommand(strSQL, connection);
363 try
364 {
365 connection.Open();
366 SqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
367 return myReader;
368 }
369 catch (System.Data.SqlClient.SqlException e)
370 {
371
372 throw e;
373 }
374
375 }
376 /// <summary>
377 /// 执行查询语句，返回DataSet
378 /// </summary>
379 /// <param name="SQLString">查询语句</param>
380 /// <returns>DataSet</returns>
381 public static DataSet Query(string SQLString)
382 {
383 using (SqlConnection connection = new SqlConnection(connectionString))
384 {
385 DataSet ds = new DataSet();
386 try
387 {
388 connection.Open();
389 SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
390 command.Fill(ds, "ds");
391 }
392 catch (System.Data.SqlClient.SqlException e)
393 {
394 LogHelper.WriteErrorLog(String.Format(@"Query-失败：提交时间：{0},执行SQL语句：{1}", DateTime.Now, SQLString), e);
395 throw e;
396 }
397 return ds;
398 }
399 }
400 public static DataSet Query(string SQLString, int Times)
401 {
402 using (SqlConnection connection = new SqlConnection(connectionString))
403 {
404 DataSet ds = new DataSet();
405 try
406 {
407 connection.Open();
408 SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
409 command.SelectCommand.CommandTimeout = Times;
410 command.Fill(ds, "ds");
411 }
412 catch (System.Data.SqlClient.SqlException e)
413 {
414 LogHelper.WriteErrorLog(String.Format(@"Query-失败：提交时间：{0},执行SQL语句：{1}",DateTime.Now, SQLString), e);
415 throw e;
416 }
417 return ds;
418 }
419 }
420
421
422
423 #endregion
424
425 #region 执行带参数的SQL语句
426
427 /// <summary>
428 /// 执行SQL语句，返回影响的记录数
429 /// </summary>
430 /// <param name="SQLString">SQL语句</param>
431 /// <returns>影响的记录数</returns>
432 public static int ExecuteSql(string SQLString, params SqlParameter[] cmdParms)
433 {
434 using (SqlConnection connection = new SqlConnection(connectionString))
435 {
436 using (SqlCommand cmd = new SqlCommand())
437 {
438 try
439 {
440 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
441 int rows = cmd.ExecuteNonQuery();
442 cmd.Parameters.Clear();
443 return rows;
444 }
445 catch (System.Data.SqlClient.SqlException e)
446 {
447 throw e;
448 }
449 }
450 }
451 }
452
453
454 /// <summary>
455 /// 执行多条SQL语句，实现数据库事务。
456 /// </summary>
457 /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>
458 public static void ExecuteSqlTran(Hashtable SQLStringList)
459 {
460 using (SqlConnection conn = new SqlConnection(connectionString))
461 {
462 conn.Open();
463 using (SqlTransaction trans = conn.BeginTransaction())
464 {
465 SqlCommand cmd = new SqlCommand();
466 try
467 {
468 //循环
469 foreach (DictionaryEntry myDE in SQLStringList)
470 {
471 string cmdText = myDE.Key.ToString();
472 SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;
473 PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
474 int val = cmd.ExecuteNonQuery();
475 cmd.Parameters.Clear();
476 }
477 trans.Commit();
478 }
479 catch(Exception e)
480 {
481
482 trans.Rollback();
483 throw;
484 }
485 }
486 }
487 }
488 /// <summary>
489 /// 执行多条SQL语句，实现数据库事务。
490 /// </summary>
491 /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>
492 public static void ExecuteSqlTranWithIndentity(Hashtable SQLStringList)
493 {
494 using (SqlConnection conn = new SqlConnection(connectionString))
495 {
496 conn.Open();
497 using (SqlTransaction trans = conn.BeginTransaction())
498 {
499 SqlCommand cmd = new SqlCommand();
500 try
501 {
502 int indentity = 0;
503 //循环
504 foreach (DictionaryEntry myDE in SQLStringList)
505 {
506 string cmdText = myDE.Key.ToString();
507 SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;
508 foreach (SqlParameter q in cmdParms)
509 {
510 if (q.Direction == ParameterDirection.InputOutput)
511 {
512 q.Value = indentity;
513 }
514 }
515 PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
516 int val = cmd.ExecuteNonQuery();
517 foreach (SqlParameter q in cmdParms)
518 {
519 if (q.Direction == ParameterDirection.Output)
520 {
521 indentity = Convert.ToInt32(q.Value);
522 }
523 }
524 cmd.Parameters.Clear();
525 }
526 trans.Commit();
527 }
528 catch(Exception e)
529 {
530
531 trans.Rollback();
532 throw;
533 }
534 }
535 }
536 }
537 /// <summary>
538 /// 执行一条计算查询结果语句，返回查询结果（object）。
539 /// </summary>
540 /// <param name="SQLString">计算查询结果语句</param>
541 /// <returns>查询结果（object）</returns>
542 public static object GetSingle(string SQLString, params SqlParameter[] cmdParms)
543 {
544 using (SqlConnection connection = new SqlConnection(connectionString))
545 {
546 using (SqlCommand cmd = new SqlCommand())
547 {
548 try
549 {
550 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
551 object obj = cmd.ExecuteScalar();
552 cmd.Parameters.Clear();
553 if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
554 {
555 return null;
556 }
557 else
558 {
559 return obj;
560 }
561 }
562 catch (System.Data.SqlClient.SqlException e)
563 {
564
565 throw e;
566 }
567 }
568 }
569 }
570
571 /// <summary>
572 /// 执行查询语句，返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
573 /// </summary>
574 /// <param name="strSQL">查询语句</param>
575 /// <returns>SqlDataReader</returns>
576 public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms)
577 {
578 SqlConnection connection = new SqlConnection(connectionString);
579 SqlCommand cmd = new SqlCommand();
580 try
581 {
582 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
583 SqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
584 cmd.Parameters.Clear();
585 return myReader;
586 }
587 catch (System.Data.SqlClient.SqlException e)
588 {
589
590 throw e;
591 }
592 // finally
593 // {
594 // cmd.Dispose();
595 // connection.Close();
596 // }
597
598 }
599
600 /// <summary>
601 /// 执行查询语句，返回DataSet
602 /// </summary>
603 /// <param name="SQLString">查询语句</param>
604 /// <returns>DataSet</returns>
605 public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)
606 {
607 using (SqlConnection connection = new SqlConnection(connectionString))
608 {
609 SqlCommand cmd = new SqlCommand();
610 PrepareCommand(cmd, connection, null, SQLString, cmdParms);
611 using (SqlDataAdapter da = new SqlDataAdapter(cmd))
612 {
613 DataSet ds = new DataSet();
614 try
615 {
616 da.Fill(ds, "ds");
617 cmd.Parameters.Clear();
618 }
619 catch (System.Data.SqlClient.SqlException ex)
620 {
621 LogHelper.WriteErrorLog(String.Format(@"DbHelperSQL.Query（执行查询语句）-失败：提交时间：{0}", DateTime.Now), ex);
622 }
623 return ds;
624 }
625 }
626 }
627
628
629 private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, string cmdText, SqlParameter[] cmdParms)
630 {
631 if (conn.State != ConnectionState.Open)
632 conn.Open();
633 cmd.Connection = conn;
634 cmd.CommandText = cmdText;
635 if (trans != null)
636 cmd.Transaction = trans;
637 cmd.CommandType = CommandType.Text;//cmdType;
638 if (cmdParms != null)
639 {
640
641
642 foreach (SqlParameter parameter in cmdParms)
643 {
644 if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
645 (parameter.Value == null))
646 {
647 parameter.Value = DBNull.Value;
648 }
649 cmd.Parameters.Add(parameter);
650 }
651 }
652 }
653
654 #endregion
655
656 #region 存储过程操作
657
658 /// <summary>
659 /// 执行存储过程，返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
660 /// </summary>
661 /// <param name="storedProcName">存储过程名</param>
662 /// <param name="parameters">存储过程参数</param>
663 /// <returns>SqlDataReader</returns>
664 public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)
665 {
666 SqlConnection connection = new SqlConnection(connectionString);
667 SqlDataReader returnReader;
668 connection.Open();
669 SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
670 command.CommandType = CommandType.StoredProcedure;
671 returnReader = command.ExecuteReader(CommandBehavior.CloseConnection);
672 return returnReader;
673
674 }
675
676
677 /// <summary>
678 /// 执行存储过程
679 /// </summary>
680 /// <param name="storedProcName">存储过程名</param>
681 /// <param name="parameters">存储过程参数</param>
682 /// <param name="tableName">DataSet结果中的表名</param>
683 /// <returns>DataSet</returns>
684 public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)
685 {
686 using (SqlConnection connection = new SqlConnection(connectionString))
687 {
688 DataSet dataSet = new DataSet();
689 connection.Open();
690 SqlDataAdapter sqlDA = new SqlDataAdapter();
691 sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
692 sqlDA.Fill(dataSet, tableName);
693 connection.Close();
694 return dataSet;
695 }
696 }
697 public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName, int Times)
698 {
699 using (SqlConnection connection = new SqlConnection(connectionString))
700 {
701 DataSet dataSet = new DataSet();
702 connection.Open();
703 SqlDataAdapter sqlDA = new SqlDataAdapter();
704 sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
705 sqlDA.SelectCommand.CommandTimeout = Times;
706 sqlDA.Fill(dataSet, tableName);
707 connection.Close();
708 return dataSet;
709 }
710 }
711
712
713 /// <summary>
714 /// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值)
715 /// </summary>
716 /// <param name="connection">数据库连接</param>
717 /// <param name="storedProcName">存储过程名</param>
718 /// <param name="parameters">存储过程参数</param>
719 /// <returns>SqlCommand</returns>
720 private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
721 {
722 SqlCommand command = new SqlCommand(storedProcName, connection);
723 command.CommandType = CommandType.StoredProcedure;
724 foreach (SqlParameter parameter in parameters)
725 {
726 if (parameter != null)
727 {
728 // 检查未分配值的输出参数,将其分配以DBNull.Value.
729 if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
730 (parameter.Value == null))
731 {
732 parameter.Value = DBNull.Value;
733 }
734 command.Parameters.Add(parameter);
735 }
736 }
737
738 return command;
739 }
740
741 /// <summary>
742 /// 执行存储过程，返回影响的行数
743 /// </summary>
744 /// <param name="storedProcName">存储过程名</param>
745 /// <param name="parameters">存储过程参数</param>
746 /// <param name="rowsAffected">影响的行数</param>
747 /// <returns></returns>
748 public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)
749 {
750 using (SqlConnection connection = new SqlConnection(connectionString))
751 {
752 int result;
753 connection.Open();
754 SqlCommand command = BuildIntCommand(connection, storedProcName, parameters);
755 rowsAffected = command.ExecuteNonQuery();
756 result = (int)command.Parameters["ReturnValue"].Value;
757 //Connection.Close();
758 return result;
759 }
760 }
761
762 /// <summary>
763 /// 创建 SqlCommand 对象实例(用来返回一个整数值)
764 /// </summary>
765 /// <param name="storedProcName">存储过程名</param>
766 /// <param name="parameters">存储过程参数</param>
767 /// <returns>SqlCommand 对象实例</returns>
768 private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)
769 {
770 SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);
771 command.Parameters.Add(new SqlParameter("ReturnValue",
772 SqlDbType.Int, 4, ParameterDirection.ReturnValue,
773 false, 0, 0, string.Empty, DataRowVersion.Default, null));
774 return command;
775 }
776 #endregion
777
778 }
779
780
781
MySql
public class DataHelper
{
//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.
public static string connectionString = ConfigurationManager.ConnectionStrings["ReadContextMysql"].ConnectionString;
//public DbHelperMySQL()
//{
//}
#region 公用方法
/// <summary>
/// 得到最大值
/// </summary>
/// <param name="FieldName"></param>
/// <param name="TableName"></param>
/// <returns></returns>
public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
/// <summary>
/// 是否存在
/// </summary>
/// <param name="strSql"></param>
/// <returns></returns>
public static bool Exists(string strSql)
{
object obj = GetSingle(strSql);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
/// <summary>
/// 是否存在（基于MySqlParameter）
/// </summary>
/// <param name="strSql"></param>
/// <param name="cmdParms"></param>
/// <returns></returns>
public static bool Exists(string strSql, params MySqlParameter[] cmdParms)
{
object obj = GetSingle(strSql, cmdParms);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
#endregion
#region 执行简单SQL语句
/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
public static int ExecuteSqlByTime(string SQLString, int Times)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.CommandTimeout = Times;
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
/// <summary>
/// 执行MySql和Oracle滴混合事务
/// </summary>
/// <param name="list">SQL命令行列表</param>
/// <param name="oracleCmdSqlList">Oracle命令行列表</param>
/// <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>
//public static int ExecuteSqlTran(List<CommandInfo> list, List<CommandInfo> oracleCmdSqlList)
//{
// using (MySqlConnection conn = new MySqlConnection(connectionString))
// {
// conn.Open();
// MySqlCommand cmd = new MySqlCommand();
// cmd.Connection = conn;
// MySqlTransaction tx = conn.BeginTransaction();
// cmd.Transaction = tx;
// try
// {
// foreach (CommandInfo myDE in list)
// {
// string cmdText = myDE.CommandText;
// MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
// PrepareCommand(cmd, conn, tx, cmdText, cmdParms);
// if (myDE.EffentNextType == EffentNextType.SolicitationEvent)
// {
// if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
// {
// tx.Rollback();
// throw new Exception("违背要求"+myDE.CommandText+"必须符合select count(..的格式");
// //return 0;
// }
// object obj = cmd.ExecuteScalar();
// bool isHave = false;
// if (obj == null && obj == DBNull.Value)
// {
// isHave = false;
// }
// isHave = Convert.ToInt32(obj) > 0;
// if (isHave)
// {
// //引发事件
// myDE.OnSolicitationEvent();
// }
// }
// if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine)
// {
// if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
// {
// tx.Rollback();
// throw new Exception("SQL:违背要求" + myDE.CommandText + "必须符合select count(..的格式");
// //return 0;
// }
// object obj = cmd.ExecuteScalar();
// bool isHave = false;
// if (obj == null && obj == DBNull.Value)
// {
// isHave = false;
// }
// isHave = Convert.ToInt32(obj) > 0;
// if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave)
// {
// tx.Rollback();
// throw new Exception("SQL:违背要求" + myDE.CommandText + "返回值必须大于0");
// //return 0;
// }
// if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave)
// {
// tx.Rollback();
// throw new Exception("SQL:违背要求" + myDE.CommandText + "返回值必须等于0");
// //return 0;
// }
// continue;
// }
// int val = cmd.ExecuteNonQuery();
// if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0)
// {
// tx.Rollback();
// throw new Exception("SQL:违背要求" + myDE.CommandText + "必须有影响行");
// //return 0;
// }
// cmd.Parameters.Clear();
// }
// string oraConnectionString = PubConstant.GetConnectionString("ConnectionStringPPC");
// bool res = OracleHelper.ExecuteSqlTran(oraConnectionString, oracleCmdSqlList);
// if (!res)
// {
// tx.Rollback();
// throw new Exception("执行失败");
// // return -1;
// }
// tx.Commit();
// return 1;
// }
// catch (MySql.Data.MySqlClient.MySqlException e)
// {
// tx.Rollback();
// throw e;
// }
// catch (Exception e)
// {
// tx.Rollback();
// throw e;
// }
// }
//}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>
public static int ExecuteSqlTran(List<String> SQLStringList)
{
using (MySqlConnection conn = new MySqlConnection(connectionString))
{
conn.Open();
MySqlCommand cmd = new MySqlCommand();
cmd.Connection = conn;
MySqlTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
int count = 0;
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n];
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
count += cmd.ExecuteNonQuery();
}
}
tx.Commit();
return count;
}
catch
{
tx.Rollback();
return 0;
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <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>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString, string content)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand(SQLString, connection);
MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
myParameter.Value = content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <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>
/// <returns>影响的记录数</returns>
public static object ExecuteSqlGet(string SQLString, string content)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand(SQLString, connection);
MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
myParameter.Value = content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 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)
/// </summary>
/// <param name="strSQL">SQL语句</param>
/// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand(strSQL, connection);
MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@fs", SqlDbType.Image);
myParameter.Value = fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 执行一条计算查询结果语句，返回查询结果（object）。
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果（object）</returns>
public static object GetSingle(string SQLString)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
public static object GetSingle(string SQLString, int Times)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
{
try
{
connection.Open();
cmd.CommandTimeout = Times;
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
connection.Close();
throw e;
}
}
}
}
/// <summary>
/// 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 )
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>MySqlDataReader</returns>
public static MySqlDataReader ExecuteReader(string strSQL)
{
MySqlConnection connection = new MySqlConnection(connectionString);
MySqlCommand cmd = new MySqlCommand(strSQL, connection);
try
{
connection.Open();
MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
return myReader;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
}
/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
connection.Open();
try
{
using (MySqlCommand cmd=new MySqlCommand(SQLString,connection))
{
using (MySqlDataAdapter command = new MySqlDataAdapter(cmd))
{
DataSet ds = new DataSet();
command.Fill(ds);
return ds;
}
}
}
catch (MySql.Data.MySqlClient.MySqlException ex)
{
throw new Exception(ex.Message);
}
}
}
public static DataSet Query(string SQLString, int Times)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
command.SelectCommand.CommandTimeout = Times;
command.Fill(ds, "ds");
}
catch (MySql.Data.MySqlClient.MySqlException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
#endregion
#region 执行带参数的SQL语句
/// <summary>
/// 执行SQL语句，返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString, params MySqlParameter[] cmdParms)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
}
}
}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
public static void ExecuteSqlTran(Hashtable SQLStringList)
{
using (MySqlConnection conn = new MySqlConnection(connectionString))
{
conn.Open();
using (MySqlTransaction trans = conn.BeginTransaction())
{
MySqlCommand cmd = new MySqlCommand();
try
{
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
string cmdText = myDE.Key.ToString();
MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Value;
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
}
trans.Commit();
}
catch
{
trans.Rollback();
throw;
}
}
}
}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
//public static int ExecuteSqlTran(System.Collections.Generic.List<CommandInfo> cmdList)
//{
// using (MySqlConnection conn = new MySqlConnection(connectionString))
// {
// conn.Open();
// using (MySqlTransaction trans = conn.BeginTransaction())
// {
// MySqlCommand cmd = new MySqlCommand();
// try
// { int count = 0;
// //循环
// foreach (CommandInfo myDE in cmdList)
// {
// string cmdText = myDE.CommandText;
// MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
// PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
// if (myDE.EffentNextType == EffentNextType.WhenHaveContine || myDE.EffentNextType == EffentNextType.WhenNoHaveContine)
// {
// if (myDE.CommandText.ToLower().IndexOf("count(") == -1)
// {
// trans.Rollback();
// return 0;
// }
// object obj = cmd.ExecuteScalar();
// bool isHave = false;
// if (obj == null && obj == DBNull.Value)
// {
// isHave = false;
// }
// isHave = Convert.ToInt32(obj) > 0;
// if (myDE.EffentNextType == EffentNextType.WhenHaveContine && !isHave)
// {
// trans.Rollback();
// return 0;
// }
// if (myDE.EffentNextType == EffentNextType.WhenNoHaveContine && isHave)
// {
// trans.Rollback();
// return 0;
// }
// continue;
// }
// int val = cmd.ExecuteNonQuery();
// count += val;
// if (myDE.EffentNextType == EffentNextType.ExcuteEffectRows && val == 0)
// {
// trans.Rollback();
// return 0;
// }
// cmd.Parameters.Clear();
// }
// trans.Commit();
// return count;
// }
// catch
// {
// trans.Rollback();
// throw;
// }
// }
// }
//}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
//public static void ExecuteSqlTranWithIndentity(System.Collections.Generic.List<CommandInfo> SQLStringList)
//{
// using (MySqlConnection conn = new MySqlConnection(connectionString))
// {
// conn.Open();
// using (MySqlTransaction trans = conn.BeginTransaction())
// {
// MySqlCommand cmd = new MySqlCommand();
// try
// {
// int indentity = 0;
// //循环
// foreach (CommandInfo myDE in SQLStringList)
// {
// string cmdText = myDE.CommandText;
// MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Parameters;
// foreach (MySqlParameter q in cmdParms)
// {
// if (q.Direction == ParameterDirection.InputOutput)
// {
// q.Value = indentity;
// }
// }
// PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
// int val = cmd.ExecuteNonQuery();
// foreach (MySqlParameter q in cmdParms)
// {
// if (q.Direction == ParameterDirection.Output)
// {
// indentity = Convert.ToInt32(q.Value);
// }
// }
// cmd.Parameters.Clear();
// }
// trans.Commit();
// }
// catch
// {
// trans.Rollback();
// throw;
// }
// }
// }
//}
/// <summary>
/// 执行多条SQL语句，实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
public static void ExecuteSqlTranWithIndentity(Hashtable SQLStringList)
{
using (MySqlConnection conn = new MySqlConnection(connectionString))
{
conn.Open();
using (MySqlTransaction trans = conn.BeginTransaction())
{
MySqlCommand cmd = new MySqlCommand();
try
{
int indentity = 0;
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
string cmdText = myDE.Key.ToString();
MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Value;
foreach (MySqlParameter q in cmdParms)
{
if (q.Direction == ParameterDirection.InputOutput)
{
q.Value = indentity;
}
}
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val = cmd.ExecuteNonQuery();
foreach (MySqlParameter q in cmdParms)
{
if (q.Direction == ParameterDirection.Output)
{
indentity = Convert.ToInt32(q.Value);
}
}
cmd.Parameters.Clear();
}
trans.Commit();
}
catch
{
trans.Rollback();
throw;
}
}
}
}
/// <summary>
/// 执行一条计算查询结果语句，返回查询结果（object）。
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果（object）</returns>
public static object GetSingle(string SQLString, params MySqlParameter[] cmdParms)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
using (MySqlCommand cmd = new MySqlCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
object obj = cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
}
}
}
/// <summary>
/// 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 )
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>MySqlDataReader</returns>
public static MySqlDataReader ExecuteReader(string SQLString, params MySqlParameter[] cmdParms)
{
MySqlConnection connection = new MySqlConnection(connectionString);
MySqlCommand cmd = new MySqlCommand();
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
cmd.Parameters.Clear();
return myReader;
}
catch (MySql.Data.MySqlClient.MySqlException e)
{
throw e;
}
// finally
// {
// cmd.Dispose();
// connection.Close();
// }
}
/// <summary>
/// 执行查询语句，返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString, params MySqlParameter[] cmdParms)
{
using (MySqlConnection connection = new MySqlConnection(connectionString))
{
MySqlCommand cmd = new MySqlCommand();
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
using (MySqlDataAdapter da = new MySqlDataAdapter(cmd))
{
DataSet ds = new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
}
catch (MySql.Data.MySqlClient.MySqlException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
}
private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, string cmdText, MySqlParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (trans != null)
cmd.Transaction = trans;
cmd.CommandType = CommandType.Text;//cmdType;
if (cmdParms != null)
{
foreach (MySqlParameter parameter in cmdParms)
{
if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
(parameter.Value == null))
{
parameter.Value = DBNull.Value;
}
cmd.Parameters.Add(parameter);
}
}
}
#endregion
}
web.config
<connectionStrings>
<add name="TingZiUnique" connectionString="Data Source=服务器地址;Initial Catalog=AssignSystem;Integrated Security=false;User ID=链接数据库用户名（sa）;Password=链接数据库密码（123456）)!*;MultipleActiveResultSets=True" providerName="System.Data.SqlClient"/>
</connectionStrings>
其实上面那句是些着玩的小面这句就够了
<connectionStrings>
<add name="TingZiUnique" connectionString="Data Source=.;database=数据库名称;uid=用户名;pwd=密码"/> </connectionStrings>
PS：小菜一只请多多指教，可能有错请指出
来源：https://www.cnblogs.com/ZxtIsCnblogs/p/7698301.html