概括ADO.NET数据库连接的所有形式(基础）
摘要：一切要从基础抓起，这里描述了几种常用的ADO.NET数据库的连接形式，是在你以后编程工作中会经常使用的。
你可能熟悉其中部分数据库读取的形式，但是熟悉全部的估计很少，或者你完全忘记了，因为这些形式被封装到你自己框架的底层，自己搞过一两次就在也没有动手写过了。但是笔者觉得这部分知识是应该牢固掌握的，这个是基础。
第一种：通过直接在cs文件中编写查询语句调用 dbcom.ExecuteNonQuery();执行插入数据
1 //连接字符串
2 string ConnectionString = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ConnectionString;
3 string ProviderName = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ProviderName;
4 DbProviderFactory dbproviderfactory = DbProviderFactories.GetFactory(ProviderName);
5 DbConnection dbcon = dbproviderfactory.CreateConnection();
6 dbcon.ConnectionString = ConnectionString;
7 DbCommand dbcom = dbproviderfactory.CreateCommand();
8 dbcom.Connection = dbcon;
9 dbcom.CommandText = "Insert into dt_Table01(name,psw) values(@name,@psw)";
10 dbcom.CommandType = CommandType.Text;
11
12 //添加参数
13 DbParameter dbparameter = dbproviderfactory.CreateParameter();
14 dbparameter.ParameterName = "@name";
15 dbparameter.DbType = DbType.String;
16 dbparameter.Value = "xiaolong";
17 dbcom.Parameters.Add(dbparameter);
18 dbparameter = dbproviderfactory.CreateParameter();
19 dbparameter.ParameterName = "@psw";
20 dbparameter.DbType = DbType.String;
21 dbparameter.Value = "123";
22 dbcom.Parameters.Add(dbparameter);
23 dbcon.Open();
24 try
25 {
26 dbcom.ExecuteNonQuery();
27 }
28 catch(Exception ex)
29 {
30 //将错误写入日志里
31 AddLogError(ex.ToString());
32 Response.Redirect("~/ErrorPage.aspx");
33 }
34 finally
35 {
36 dbcon.Close();
37 }
第二种：当然是调用存储过程
1 //存储过程的
2 string ConnectionString = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ConnectionString;
3 string ProviderName = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ProviderName;
4 DbProviderFactory dbproviderfactory = DbProviderFactories.GetFactory(ProviderName);
5 DbConnection dbcon = dbproviderfactory.CreateConnection();
6 dbcon.ConnectionString = ConnectionString;
7 DbCommand dbcom = dbproviderfactory.CreateCommand();
8 dbcom.Connection = dbcon;
9 dbcom.CommandType = CommandType.StoredProcedure;
10 dbcom.CommandText = "InsertTable01";
11 DbParameter dbparameter = dbproviderfactory.CreateParameter();
12 dbparameter.DbType = DbType.String;
13 dbparameter.ParameterName = "@name";
14 dbparameter.Value = "xiaohe";
15 dbcom.Parameters.Add(dbparameter);
16 dbparameter = dbproviderfactory.CreateParameter();
17 dbparameter.ParameterName = "@psw";
18 dbparameter.DbType = DbType.String;
19 dbparameter.Value = "123";
20 dbcom.Parameters.Add(dbparameter);
21 dbcon.Open();
22 try
23 {
24 dbcom.ExecuteNonQuery();
25 }
26 catch (Exception ex)
27 {
28 AddLogError(ex.ToString());
29 Response.Redirect("~/ErrorPage.aspx");
30 }
31 finally
32 {
33 dbcon.Close();
34 }
第三种：就是可能同时插入两张表或者三张表或者更多。必须是同时，运用到了事务回滚机制。存储过程写法就不给出来了和上面一样。只是在存储过程编写事务。
1 //同时插入两张的表
2 string ConnectionString = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ConnectionString;
3 string ProviderName = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ProviderName;
4 DbProviderFactory dbproviderfactory = DbProviderFactories.GetFactory(ProviderName);
5 DbConnection dbcon = dbproviderfactory.CreateConnection();
6 dbcon.ConnectionString = ConnectionString;
7 DbCommand dbcom = dbproviderfactory.CreateCommand();
8 dbcom.Connection = dbcon;
9 dbcom.CommandType = CommandType.Text;
10
11 DbParameter dbparameter = dbproviderfactory.CreateParameter();
12 dbparameter.DbType = DbType.String;
13 dbparameter.ParameterName = "@name";
14 dbparameter.Value = "xiaohei";
15 dbcom.Parameters.Add(dbparameter);
16 dbparameter = dbproviderfactory.CreateParameter();
17 dbparameter.ParameterName = "@psw";
18 dbparameter.DbType = DbType.String;
19 dbparameter.Value = "123";
20 dbcom.Parameters.Add(dbparameter);
21 dbparameter = dbproviderfactory.CreateParameter();
22 dbparameter.DbType = DbType.String;
23 dbparameter.ParameterName = "@teacher";
24 dbparameter.Value = "heihei";
25 dbcom.Parameters.Add(dbparameter);
26
27 dbcon.Open();
28 //事务开始
29 DbTransaction dbtran = dbcon.BeginTransaction();
30 dbcom.Transaction = dbtran;
31
32 try
33 {
34 dbcom.CommandText = "insert into dt_table01(name,psw) values(@name,@psw)";
35 dbcom.ExecuteNonQuery();
36 dbcom.CommandText = "insert into dt_table03(teacher,psw) values(@teacher,@psw)";
37 dbcom.ExecuteNonQuery();
38 //成功就提交
39 dbtran.Commit();
40 }
41 catch (Exception ex)
42 {
43 //出错就回滚
44 dbtran.Rollback();
45 AddLogError(ex.ToString());
46 Response.Redirect("~/ErrorPage.aspx");
47 }
48 finally
49 {
50 dbcon.Close();
51 dbtran.Dispose();
52 }
第四种：通过使用DbDataAdapter来获得查询的结果
1 //查询数据库
2 string ConnectionString = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ConnectionString;
3 string ProviderName = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ProviderName;
4 DbProviderFactory dbproviderfactory = DbProviderFactories.GetFactory(ProviderName);
5 DbConnection dbcon = dbproviderfactory.CreateConnection();
6 dbcon.ConnectionString = ConnectionString;
7 DbCommand dbcom = dbproviderfactory.CreateCommand();
8 dbcom.Connection = dbcon;
9 dbcom.CommandText = "Select * from dt_Table01 where name=@name";
10 dbcom.CommandType = CommandType.Text;
11 DbParameter dbparameter = dbproviderfactory.CreateParameter();
12 dbparameter.ParameterName = "@name";
13 dbparameter.DbType = DbType.String;
14 dbparameter.Value = "xiaolong";
15 dbcom.Parameters.Add(dbparameter);
16 DataSet ds = new DataSet();
17 DbDataAdapter dbDataAdapeter = dbproviderfactory.CreateDataAdapter();
18 dbDataAdapeter.SelectCommand = dbcom;
19 try
20 {
21 dbDataAdapeter.Fill(ds, "data");
22 }
23 catch (Exception ex)
24 {
25 AddLogError(ex.ToString());
26 Response.Redirect("~/ErrorPage.aspx");
27 }
28 finally
29 {
30 dbDataAdapeter.Dispose();
31 }
第5种：使用DbDataReader或者查询结果，这里给出查询第一行第一列值，当然也可以直接调用Command.ExecuteScalar();函数
1 string ConnectionString = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ConnectionString;
2 string ProviderName = ConfigurationManager.ConnectionStrings["db_Test01ConnectionString"].ProviderName;
3 DbProviderFactory dbproviderfactory = DbProviderFactories.GetFactory(ProviderName);
4 DbConnection dbcon = dbproviderfactory.CreateConnection();
5 dbcon.ConnectionString = ConnectionString;
6 DbCommand dbcom = dbproviderfactory.CreateCommand();
7 dbcom.Connection = dbcon;
8 dbcom.CommandText = "Select * from dt_Table01 where name=@name";
9 dbcom.CommandType = CommandType.Text;
10 DbParameter dbparameter = dbproviderfactory.CreateParameter();
11 dbparameter.ParameterName = "@name";
12 dbparameter.DbType = DbType.String;
13 dbparameter.Value = "xiaolong";
14 dbcom.Parameters.Add(dbparameter);
15 dbcon.Open();
16 DbDataReader dbDataReader=null;
17 string re = string.Empty;
18 try
19 {
20 dbDataReader= dbcom.ExecuteReader(CommandBehavior.SingleRow);
21 }
22 catch (Exception ex)
23 {
24 AddLogError(ex.ToString());
25 Response.Redirect("~/ErrorPage.aspx");
26 }
27 finally
28 {
29 dbcon.Close();
30 dbDataReader.Close();
31 }
32 //读入值
33 if (dbDataReader.Read())
34 {
35 //得到第一列值
36 re = dbDataReader.GetValue(0).ToString();
37 }
38 re = re + "hah";
当然还可以自己编写一些常用的调用例如：或者查询结果第一列的值等等。
大致上就是以上这几种形式了。
存储过程，Command直接执行，DataReader,DataAdapter,事务
由于笔者知识有限，如果还有其他形式请您补充上来
