您的位置:首页 > 数据库 > Oracle

数据库操作_连接SQL Server数据库示例;连接ACCESS数据库;连接到 Oracle 数据库示例;SqlCommand 执行SQL命令示例;SqlDataReader 读取数据示例;使用DataAdapter填充数据到DataSet;使用DataTable存储数据库表;将数据库数据填充到 XML 文件;10 使用带输入参数的存储过程;11 使用带输入、输出参数的存储过程示;12 获得数据库中表的数目和名称;13 保存图片到SQL Server数据库示例;14 获得插入记录标识号;Exce

2008-04-29 23:28 2541 查看
1 连接SQL Server数据库示例

// 连接字符串

string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

// 创建SqlConnection对象

SqlConnection connection = new SqlConnection(ConnectionString);

try

{

// 打开数据库连接

connection.Open();

myLabel.Text = "连接数据库成功";

}

catch

{

myLabel.Text = "连接数据库失败";

}

finally

{

// 关闭数据库连接

connection.Close();

}

<appSettings>

<add key="ConnectionSqlServer" value="Server=(local);User id=sa;Pwd=sa;Database=Northwind"></add>

<add key="ConnectionSqlServer1" value="Server=(local);User id=sa;Pwd=sa;"></add>

<add key="ConnectionSqlServer_tempdb" value="Server=(local);User id=sa;Pwd=sa;Database=tempdb"></add>

<add key="ConnectionDB2" value="DATABASE=SAMPLE;UID=username;PWD=password"></add>

<add key="ConnectionOracle" value="Data Source=Oracle8i;Integrated Security=yes"></add>

</appSettings>

<system.web>

2 // 连接到 ACCESS 的连接字符串

string ConnStr = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=" + Server.MapPath("grocertogo.mdb");

// 使用OleDb .NET数据提供程序创建连接

OleDbConnection oleConnection = new OleDbConnection(ConnStr);

try

{

// 打开数据库连接

oleConnection.Open();

// 显示连接成功信息

myLabel.Text = "Access数据库连接状态:" + oleConnection.State;

}

catch(Exception ex)

{

// 如果出现异常,显示异常信息

myLabel.Text = "Access数据库连接状态:" + ex.ToString();

}

finally

{

// 关闭数据库连接

oleConnection.Close();

}

3 // 连接到 Oracle 数据库示例

string ORACLE_ConnStr = "Data Source=Oracle8i;Integrated Security=yes";

// 创建 OracleConnection 对象

OracleConnection oConnection = new OracleConnection(ORACLE_ConnStr);

try

{

oConnection.Open();

myLabel.Text = "连接到 Oracle 数据库";

}

catch(Exception ex)

{

myLabel.Text = ex.ToString();

}

finally

{

oConnection.Close();

}

4 SqlCommand 执行SQL命令示例

string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

// 创建SqlConnection对象

// 创建Command对象

SqlConnection thisConnection = new SqlConnection(ConnStr);

SqlCommand thisCommand = new SqlCommand();

// 关联Connection对象

// 赋值SQL语句到CommandText属性

// 指定命令类型是Sql语句

thisCommand.Connection = thisConnection;

thisCommand.CommandText = "SELECT COUNT(*) FROM Employees";

thisCommand.CommandType = CommandType.Text;

try

{

// 打开数据库连接

thisCommand.Connection.Open();

// 获取查询结果

myLabel.Text = thisCommand.ExecuteScalar().ToString();

}

catch(SqlException ex)

{

// 如果出现异常,在Label标签中显示异常信息

myLabel.Text = ex.ToString();

}

finally

{

// 关闭数据库连接

thisCommand.Connection.Close();

}

5 SqlDataReader 读取数据示例

string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

string Sql = "SELECT LastName, FirstName FROM Employees";

SqlConnection thisConnection = new SqlConnection(ConnectionString);

SqlCommand thisCommand = new SqlCommand(Sql, thisConnection);

thisCommand.CommandType = CommandType.Text;

try

{

// 打开数据库连接

thisCommand.Connection.Open();

// 执行SQL语句,并返回DataReader对象

SqlDataReader dr = thisCommand.ExecuteReader();

// 以粗体显示标题

myLabel.Text = "<b>LastName FirstName</b><br>";

// 循环读取结果集

while(dr.Read())

{

// 读取两个列值并输出到Label中

myLabel.Text += dr["LastName"] + " " + dr["FirstName"] + "<br>";

}

// 关闭DataReader

dr.Close();

}

catch(SqlException ex)

{

// 异常处理

Response.Write(ex.ToString());

}

finally

{

// 关闭数据库连接

thisCommand.Connection.Close();

}

6 使用DataAdapter填充数据到DataSet

string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

string Sql = "SELECT EmployeeID, LastName, FirstName,Title, TitleOfCourtesy, BirthDate FROM Employees";

// 创建SqlConnection对象

// 创建DataAdapter对象并初始化

SqlConnection thisConnection = new SqlConnection(ConnectionString);

SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection);

// 创建DataSet对象

DataSet data = new DataSet();

// 填充数据到DataSet

adapter.Fill(data);

// 数据绑定

myDataGrid.DataSource = data;

myDataGrid.DataBind();

7 使用DataTable存储数据库表内容

string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

string Sql = "SELECT EmployeeID, LastName, FirstName, BirthDate FROM Employees";

// 创建SqlConnection、SqlDataAdapter对象

SqlConnection thisConnection = new SqlConnection(ConnectionString);

SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection);

// 创建DataTable对象

DataTable table = new DataTable();

// 填充数据到DataTable

adapter.Fill(table);

// 将DataTable绑定到DataGrid控件

myDataGrid.DataSource = table;

myDataGrid.DataBind();

8 将数据库数据填充到 XML 文件

// 连接字符串及 SQL 语句

string ConnString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

string Sql = "SELECT CustomerID,CompanyName,Country FROM Customers";

// 连接 SqlConnection 及 SqlDataAdapter 对象

SqlConnection thisConnection = new SqlConnection(ConnString);

SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection);

// 创建 DataSet 对象

DataSet data = new DataSet();

// 填充 DataSet

adapter.Fill(data, "Customers");

// 将 DataSet 数据其及架构填充到 Xml 文件

data.WriteXml(Server.MapPath(".") + "\\myXml.xml", XmlWriteMode.WriteSchema);

// 提示填充是否成功

Label1.Text = "填充到XML文件成功";

9 ASP.NET 使用存储过程

// 连接字符串

string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

// 创建Connection对象

SqlConnection myConn = new SqlConnection(ConnStr);

// 创建Command对象并和Connection对象关联

SqlCommand myCommand = new SqlCommand();

myCommand.Connection = myConn;

// 指定要执行的存储过程名称

myCommand.CommandText = "CustomersProc";

// 使用要执行的是存储过程

myCommand.CommandType = CommandType.StoredProcedure;

// 创建DataAdapter对象填充数据

DataSet myDS = new DataSet();

SqlDataAdapter adapter = new SqlDataAdapter(myCommand);

adapter.Fill(myDS, "Customers");

// 将返回的数据和DataGrid绑定显示

myDataGrid.DataSource = myDS.Tables["Customers"];

myDataGrid.DataBind();

10 使用带输入参数的存储过程

string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

// 创建数据库操作对象

SqlDataAdapter myAdapter = new SqlDataAdapter();

SqlCommand myCommand = new SqlCommand();

myCommand.Connection = new SqlConnection(ConnStr);

DataTable dt = new DataTable();

// 指定要调用的存储过程名称 "Customer_Select"

// 指定SqlCommand对象的命令类型为 "StoredProcedure"枚举值

myCommand.CommandText = "Customer_Select";

myCommand.CommandType = CommandType.StoredProcedure;

// 创建SqlParameter对象,指定参数名称、数据类型、长度及参数值

SqlParameter para = new SqlParameter("@country", SqlDbType.NVarChar, 15);

para.Value = DropDownList1.SelectedValue;

myCommand.Parameters.Add(para);

// 关联SqlDataAdapter与SqlCommand对象

myAdapter.SelectCommand = myCommand;

myAdapter.Fill(dt);

// 绑定DataGrid

DataGrid1.DataSource = dt;

DataGrid1.DataBind();

11 使用带输入、输出参数的存储过程示

string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

// 创建 Connection 和 Command 对象

SqlConnection myConn = new SqlConnection(ConnStr);

SqlCommand myCommand = new SqlCommand("EmployeesProc", myConn);

// 指定要执行的命令为存储过程

myCommand.CommandType = CommandType.StoredProcedure;

// 增加输入参数并赋值

myCommand.Parameters.Add("@TitleOfCourtesy", SqlDbType.NVarChar, 20);

myCommand.Parameters["@TitleOfCourtesy"].Value = myDropDownList.SelectedItem.Text;

myCommand.Parameters["@TitleOfCourtesy"].Direction = ParameterDirection.Input;

// 增加输出参数

myCommand.Parameters.Add("@empCount", SqlDbType.Int);

myCommand.Parameters["@empCount"].Direction = ParameterDirection.Output;

// 创建 DataAdapter 对象填充数据

DataSet myDS = new DataSet();

SqlDataAdapter adapter = new SqlDataAdapter(myCommand);

adapter.Fill(myDS, "Customers");

// 使用 Label 控件显示输出参数的输出值

rtnLabel.Text = myCommand.Parameters["@empCount"].Value.ToString();

// 将返回的数据和 DataGrid 绑定显示

myDataGrid.DataSource = myDS.Tables["Customers"];

myDataGrid.DataBind();

12 获得数据库中表的数目和名称 获取服务器端数据库列表

string listQuery = "SELECT name FROM sysobjects WHERE xtype = 'U'";

string sumQuery = "SELECT COUNT(*) FROM sysobjects WHERE xtype = 'U'

string db_query = "sp_helpdb";

13 保存图片到SQL Server数据库示例

// HttpPostedFile对象,用于读取图象文件属性

HttpPostedFile UpFile = UP_FILE.PostedFile;

// FileLength 变量存储图片的字节大小

int FileLength = UpFile.ContentLength;

try

{

if (FileLength == 0)

{

txtMessage.Text = "<b>您未选择上传的文件</b>";

}

else

{

// 创建存储图片文件的临时 Byte 数组

Byte[] FileByteArray = new Byte[FileLength];

// 建立数据流对象

Stream StreamObject = UpFile.InputStream;

// 读取图象文件数据,FileByteArray为数据储存体,0为数据指针位置、FileLnegth为数据长度

StreamObject.Read(FileByteArray,0,FileLength);

// 数据库操作

string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

string query = "INSERT INTO ImageTable (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@ImageData, @ImageContentType, @ImageDescription, @ImageSize)";

SqlCommand myCommand = new SqlCommand(query, new SqlConnection(ConnStr));

// 添加各项参数并赋值

myCommand.Parameters.Add("@ImageData", SqlDbType.Image);

myCommand.Parameters.Add("@ImageContentType", SqlDbType.VarChar, 50);

myCommand.Parameters.Add("@ImageDescription", SqlDbType.VarChar, 200);

myCommand.Parameters.Add("@ImageSize", SqlDbType.BigInt);

myCommand.Parameters["@ImageData"].Value = FileByteArray;

myCommand.Parameters["@ImageContentType"].Value = UpFile.ContentType;

myCommand.Parameters["@ImageDescription"].Value = txtDescription.Text;

myCommand.Parameters["@ImageSize"].Value = FileLength;

// 执行数据库操作

myCommand.Connection.Open();

myCommand.ExecuteNonQuery();

myCommand.Connection.Close();

// 提示上传成功

txtMessage.Text = "<b>上传文件成功</b>";

}

}

catch (Exception ex)

{

// 使用 Label 标签显示异常

txtMessage.Text = ex.Message.ToString();

}

14 获得插入记录标识号的示例

// 数据库连接字符串

string ConnStr = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];

// 创建插入SQL语句及调用@@identity函数返回标识值

string insert_query = "insert into Categories (CategoryName,Description) values ('IT', 'Internet');"

+ "SELECT @@identity AS 'identity';";

// 执行数据库操作

SqlCommand myCommand = new SqlCommand(insert_query, new SqlConnection(ConnStr));

myCommand.Connection.Open();

myLabel.Text = myCommand.ExecuteScalar().ToString();

myCommand.Connection.Close();

15 如何读取Excel表格中的数据

// 获取Excep文件的完整路径

string source = File1.Value;

string ConnStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + source + ";Extended Properties=Excel 8.0";

string query = "SELECT * FROM [Sheet1$]";

OleDbCommand oleCommand = new OleDbCommand(query, new OleDbConnection(ConnStr));

OleDbDataAdapter oleAdapter = new OleDbDataAdapter(oleCommand);

DataSet myDataSet = new DataSet();

// 将 Excel 的[Sheet1]表内容填充到 DataSet 对象

oleAdapter.Fill(myDataSet, "[Sheet1$]");

// 数据绑定

DataGrid1.DataSource = myDataSet;

DataGrid1.DataMember = "[Sheet1$]";

DataGrid1.DataBind();
内容来自用户分享和网络整理,不保证内容的准确性,如有侵权内容,可联系管理员处理 点击这里给我发消息
标签: 
相关文章推荐