.net 如何链接sql 数据库

Question

晕  第一种在web.config里配置好 在private string source = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;读取第二种就直接写如 string connectionString =@"Data Source=zhulong\sqlexpress;Initial Catalog=DaPeng;User ID=sa ;password=123";
 SqlConnection connection = new SqlConnection(connectionString);

Answer 1

WEB.CONFIG
=======================================================
<appSettings>
    <add key="ConnectionString" value="server=Develop2;uid=sa;database=AnQuanDB" />
</appSettings>using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
 
namespace DatabaseOperate
{
    class SqlOperateInfo
    {
        //Suppose your ServerName is "aa",DatabaseName is "bb",UserName is "cc", Password is "dd"
        private string sqlConnectionCommand = "Data Source=aa;Initial Catalog=bb;User ID=cc;Pwd=dd";
        //This table contains two columns:KeywordID int not null,KeywordName varchar(100) not null
        private string dataTableName = "Basic_Keyword_Test";
 
        private string storedProcedureName = "Sp_InertToBasic_Keyword_Test";
        private string sqlSelectCommand = "Select KeywordID, KeywordName From Basic_Keyword_Test";
        //sqlUpdateCommand could contain "insert" , "delete" , "update" operate
        private string sqlUpdateCommand = "Delete From Basic_Keyword_Test Where KeywordID = 1";
 
        public void UseSqlReader()
        {
            SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.CommandType = System.Data.CommandType.Text;
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandText = sqlSelectCommand;
 
            sqlConnection.Open();
            SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
            while(sqlDataReader.Read())
            {
                //Get KeywordID and KeywordName , You can do anything you like. Here I just output them.
                int keywordid = (int)sqlDataReader[0]; 
                //the same as: int keywordid = (int)sqlDataReader["KeywordID"]
                string keywordName = (string)sqlDataReader[1]; 
                //the same as: string keywordName = (int)sqlDataReader["KeywordName"]
                Console.WriteLine("KeywordID = " + keywordid + " , KeywordName = " + keywordName);
            }
 
            sqlDataReader.Close();
            sqlCommand.Dispose();
            sqlConnection.Close();
        }
        public void UseSqlStoredProcedure()
        {
            SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.CommandType = CommandType.StoredProcedure;
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandText = storedProcedureName;
 
            sqlConnection.Open();
            sqlCommand.ExecuteNonQuery();
            //you can use reader here,too.as long as you modify the sp and let it like select * from ....
 
            sqlCommand.Dispose();
            sqlConnection.Close();
        }
        public void UseSqlDataSet()
        {
            SqlConnection sqlConnection = new SqlConnection(sqlConnectionCommand);
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.CommandType = System.Data.CommandType.Text;
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandText = sqlSelectCommand;
 
            sqlConnection.Open();
            SqlDataAdapter sqlDataAdapter = new SqlDataAdapter();
            sqlDataAdapter.SelectCommand = sqlCommand;
            DataSet dataSet = new DataSet();
            //sqlCommandBuilder is for update the dataset to database
            SqlCommandBuilder sqlCommandBuilder = new SqlCommandBuilder(sqlDataAdapter);
            sqlDataAdapter.Fill(dataSet, dataTableName);
 
            //Do something to dataset then you can update it to Database.Here I just add a row
            DataRow row = dataSet.Tables[0].NewRow();
            row[0] = 10000;
            row[1] = "new row";
            dataSet.Tables[0].Rows.Add(row);
 
            sqlDataAdapter.Update(dataSet, dataTableName);
 
            sqlCommand.Dispose();
            sqlDataAdapter.Dispose();
            sqlConnection.Close();
        }
    }
}
资料引用:http://www.knowsky.com/345354.html

Answer 2

C#操作数据库类!2007-11-05 22:13using System;
using System.Web;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
namespace DB
{
    
    /// <summary>
    /// 数据库操作基类
    /// 实现对Sql数据库的各种操作
    /// 创建时间：2007-11-5
    /// </summary>
    public class SqlDataBase
    {
        //获取Web.Config数据库连接字符串
        private readonly string SqlConnectionString = System.Configuration.ConfigurationManager.AppSettings["ConnectionString"];
        private SqlConnection cn;   //创建SQL连接
        private SqlDataAdapter sda;//创建SQL数据适配器
        private SqlDataReader sdr;   //创建SQL数据读取器
        private SqlCommand cmd;    //创建SQL命令对象
       // private OleDbParameter param;     //创建SQL参数
        private DataSet ds;     //创建数据集
        private DataView dv;    //创建视图               /// <summary>
        /// 打开数据库连接
        /// </summary>
        public void Open()
        {
            #region
            cn = new SqlConnection(SqlConnectionString);
            cn.Open();
            #endregion
        }
        /// <summary>
        /// 关闭数据库连接
        /// </summary>
        public void Close()
        {
            #region
            if (cn != null)
            {
                cn.Close();
                cn.Dispose();
            }
            #endregion
        }
        /// <summary>
        /// 返回DataSet数据集
        /// </summary>
        /// <param name="strSql">SQL语句</param>
        public DataSet GetDs(string strSql)
        {
            #region
            Open();
            sda = new SqlDataAdapter(strSql, cn);
            ds = new DataSet();
            sda.Fill(ds);
            Close();
            return ds;
            #endregion
        }        /// <summary>
        /// 添加DataSet表
        /// </summary>
        /// <param name="ds">DataSet对象</param>
        /// <param name="strSql">Sql语句</param>
        /// <param name="strTableName">表名</param>
        public void GetDs(DataSet ds, string strSql, string strTableName)
        {
            #region
            Open();
            sda = new SqlDataAdapter(strSql, cn);
            sda.Fill(ds, strTableName);
            Close();
            #endregion
        }
        /// <summary>
        /// 返回DataView数据视图
        /// </summary>
        /// <param name="strSql">Sql语句</param>
        public DataView GetDv(string strSql)
        {
            #region
            dv = GetDs(strSql).Tables[0].DefaultView;
            return dv;
            #endregion
        }
        /// <summary>
        /// 获得DataTable对象
        /// </summary>
        /// <param name="strSql">SQL语句</param>
        /// <returns></returns>
        public DataTable GetTable(string strSql)
        {
            #region
            return GetDs(strSql).Tables[0];
            #endregion
        }
        /// <summary>
        /// 获得OleDbDataReader对象 使用完须关闭DataReader,关闭数据库连接
        /// </summary>
        /// <param name="strSql">sql语句</param>
        /// <returns></returns>
        public SqlDataReader GetDataReader(string strSql)
        {
            #region
            Open();
            cmd = new SqlCommand(strSql, cn);
            sdr = cmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
            return sdr;
            #endregion
        }        /// <summary>
        /// 执行Sql语句
        /// </summary>
        /// <param name="strSql"></param>
        public void RunSql(string strSql)
        {
            #region
            Open();
            cmd = new SqlCommand(strSql, cn);
            cmd.ExecuteNonQuery();
            Close();
            #endregion
        }
        /// <summary>
        /// 执行SQL语句，并返回第一行第一列结果
        /// </summary>
        /// <param name="strSql">SQL语句</param>
        /// <returns></returns>
        public string RunSqlReturnStr(string strSql)
        {
            #region
            string strReturn = "";
            Open();
            try
            {
                cmd = new SqlCommand(strSql, cn);
                strReturn = cmd.ExecuteScalar().ToString();
            }
            catch { }
            Close();
            return strReturn;
            #endregion
        }        //利用存贮过程进行数据库的插入、删除、修改操作 
        public Boolean SP_SQLCommand(SqlCommand tmpcmd)
        {
            #region
            cn = new SqlConnection(SqlConnectionString);
            tmpcmd.Connection = cn;
            tmpcmd.CommandType = CommandType.StoredProcedure;
            cn.Open();
            tmpcmd.ExecuteNonQuery();
            Close();
            return true;
            #endregion
        }        /// <summary>
        /// 执行SQL语句，并返回结果
        /// </summary>
        /// <param name="strSql">SQL语句</param>
        /// <returns></returns>
        public Boolean RunSqlReturnBool(string strSql)
        {
            #region
            int intReturn = 0;
            Open();
           // try
            {
                cmd = new SqlCommand(strSql, cn);
                intReturn = cmd.ExecuteNonQuery();
            }
          // catch { }
            Close();
            if (intReturn > 0)
                return true;
            else
                return false;
            #endregion
        }    }}
 

Answer 3

可以在web.config中配置
例连sql2000的
<connectionStrings>
     <add name="conn" connectionString="server=.;uid=sa;pwd=;database=dtDb"/>
</connectionStrings>
再获取连接字符串、创建连接对象 static readonly SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["conn"].ToString());

Answer 4

using system.data.sqlclient;//必须先导入该命名空间;这是连接Sql数据库要用的命名空间
sqlconnection con=new sqlconnection("Server=.;uid=sa;pwd=;database=db_test");
sqldataadapter sda=new sqldataadapter("select * from table_test",con);//Sql语句
dataset ds=new dataset();
sda.fill(ds);

Answer 5

string connectionString =@"Data Source=zhulong\sqlexpress;Initial Catalog=DaPeng;User ID=sa ;password=123"; 
SqlConnection connection = new SqlConnection(connectionString);

Answer 6

上面写的都很好
在sqlserver2000中，如果你的数据库是没有密码的,可以在【配置文件】中写<connectionStrings> 
    <add name="conn" connectionString="connectionString="Data Source=.;Initial Catalog=你的数据库名称;Integrated Security=True"> 
</connectionStrings> 在sqlsever2005中<connectionStrings> 
    <add name="conn" connectionString="connectionString="Data Source=.\sqlexpress;Initial Catalog=你的数据库名称;Integrated Security=True"> 
</connectionStrings> 
mysql连接vs2005的数据库代码是string connStr = String.Format("server={0};user id={1}; password={2}; database={3}; pooling=false;port=3306", "127.0.0.1", "root", "admin", "mysql");你如果想要连接mysql，需要安装一个dll文件，MySql.Data.dll，你可以去mysql官网下