1.SqlServer连接

①App.config中的配置

 <configuration> 
    <connectionStrings> 
        <add name="sqlConnstring"         connectionString="server=10.52.6.11;database=AccountDB;uid=sa;pwd=wz!sfc168;"         providerName="System.Data.SqlClient"/> 
    </connectionStrings> 
</configuration>

②SqlHelper代码实现
using System.Data.SqlClient;    //SqlServer引用

public static readonly string connString = ConfigurationManager.ConnectionStrings["sqlConnstring"].ConnectionString;  //连接字符串

 
public static DataTable ExecuteDataTable(string strSql, params SqlParameter[] parms)
{
      DataTable dt = new DataTable();
      using (SqlConnection conn = new SqlConnection(connString))
      {
           SqlCommand cmd = new SqlCommand(strSql, conn);
           //cmd.CommandType = CommandType.StoredProcedure;   //存储过程
           cmd.CommandType = CommandType.Text;                         //Sql语句
           cmd.Parameters.Clear();
           cmd.Parameters.AddRange(parms);
           conn.Open();
           SqlDataAdapter adapter = new SqlDataAdapter();
           adapter.SelectCommand = cmd;
           adapter.Fill(dt);
           return dt;
       }

}

2.Oracle连接

①App.config中的配置

<configuration> 
    <connectionStrings>
        <add name="oracleConnstring" connectionString="Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=10.152.204.10)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=MESDB)));Persist Security Info=True;User ID=sa;Password=!sa******;" providerName="Oracle.DataAccess.Client"/> 
    </connectionStrings> 
</configuration>

②OracleHelper代码实现
using Oracle.ManagedDataAccess.Client;  //引用Oracle客户端

public static readonly string connString = ConfigurationManager.ConnectionStrings["oracleConnstring"].ConnectionString;  //连接字符串

 using (OracleConnection conn = new OracleConnection(connString))
 {
          conn.Open();
          OracleCommand cmd = conn.CreateCommand();
          cmd.CommandText = "SELECT ************";        //sql脚本语句
          OracleDataReader odr = cmd.ExecuteReader();
          while (odr.HasRows)
         {
              txtResult.Text = odr.GetString(0);
         }
        odr.Close();
}