C#连接数据库的几种方法
作者：農碼一生
这篇文章介绍了C#连接数据库的几种方法，文中通过示例代码介绍的非常详细。对大家的学习或工作具有一定的参考借鉴价值，需要的朋友可以参考下
一、Oracle
查询
public static DataTable QueryData()
{
DataTable dtResult = new DataTable();
try
{
using (OracleConnection oc = new OracleConnection(HttpContext.Current.Session["DBName"].ToString().Trim()))
{
oc.Open();
string sql = @" SELECT * FROM DUAL";
OracleDataAdapter oaCmd = new OracleDataAdapter(sql, oc);
//oaCmd.SelectCommand.Parameters.Add("fDate", OracleType.VarChar, 50).Value = DateTime.Now.ToString("yyyy/MM/dd") + " " + "00:00:00";
//oaCmd.SelectCommand.Parameters.Add("eDate", OracleType.VarChar, 50).Value = DateTime.Now.ToString("yyyy/MM/dd") + " " + "23:59:59";
oaCmd.Fill(dtResult);
oc.Close();
}
}
catch (Exception ex)
{
}
return dtResult;
}更新
public static void DoInser(string login_user, string login_db)
{
try
{
//string strDBXMLFile = HttpContext.Current.Server.MapPath(HttpContext.Current.Request.ApplicationPath.ToString()) + @"\DB.XML";
//DataSet dsXML = new DataSet();
//dsXML.ReadXml(strDBXMLFile);
//DataTable dtAEPDB = dsXML.Tables["DB_NAME"];
//DB 链接
string s = "Data Source=(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = ip地址 )(PORT =端口)))(CONNECT_DATA = (SID=SID号)(SERVER = DEDICATED)));uid = 用户名; password=密码;Connection Lifetime=60;Max Pool Size=50;Min Pool Size=0;Pooling=true";
using (OracleConnection oc = new OracleConnection(s))
{
oc.Open();
string sql = @" INSERT INTO 表名 (栏位1, 栏位2, 栏位3,....) VALUES (栏位1值, 栏位2值, 栏位3值, ....)";
OracleCommand oaCmd = new OracleCommand(sql, oc);
//oaCmd.Parameters.Add("参数", OracleType.VarChar, 30).Value = "";
oaCmd.CommandType = CommandType.Text;
oaCmd.ExecuteNonQuery();
oc.Close();
}
}
catch (Exception ex)
{
}
}二、SQLServer
查询
public static DataTable QueryData()
{
DataTable dtResult = new DataTable();
try
{
using (SqlConnection sqlConnection = new SqlConnection(HttpContext.Current.Session["DBName"].ToString().Trim()))
{
sqlConnection.Open();
string sql = @" SELECT * FROM DUAL";
SqlDataAdapter sqlDa = new SqlDataAdapter(sql, sqlConnection);
sqlDa.SelectCommand.Parameters.Add("fDate", SqlDbType.VarChar, 50).Value = DateTime.Now.ToString("yyyy/MM/dd") + " " + "00:00:00";
sqlDa.SelectCommand.Parameters.Add("eDate", SqlDbType.VarChar, 50).Value = DateTime.Now.ToString("yyyy/MM/dd") + " " + "23:59:59";
sqlDa.Fill(dtResult);
sqlConnection.Close();
}
}
catch (Exception ex)
{
}
return dtResult;
}更新
public static void DoInser(string login_user, string login_db)
{
try
{
string s = "数据库链接";
using (SqlConnection sqlConnection = new SqlConnection(s))
{
sqlConnection.Open();
string sql = @" INSERT INTO 表名 (栏位1, 栏位2, 栏位3,....) VALUES (栏位1值, 栏位2值, 栏位3值, ....)";
SqlDataAdapter sqlDa = new SqlDataAdapter(sql, sqlConnection);
sqlDa.InsertCommand.Parameters.Add("参数", SqlDbType.VarChar, 30).Value = "";
SqlCommand cmd = new SqlCommand();
cmd.CommandType = CommandType.Text;
cmd.ExecuteNonQuery();
sqlConnection.Close();
}
}
catch (Exception ex)
{
}
}工具类
public DataTable ExecuteQuery(string sqlStr) //用于查询；其实是相当于提供一个可以传参的函数，到时候写一个sql语句，存在string里，传给这个函数，就会自动执行。
{
SqlConnection con = new SqlConnection("MySqlCon");
con.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = con;
cmd.CommandType = CommandType.Text;
cmd.CommandText = sqlStr;
DataTable dt = new DataTable();
SqlDataAdapter msda;
msda = new SqlDataAdapter(cmd);
msda.Fill(dt);
con.Close();
return dt;
}
public int ExecuteUpdate(string sqlStr) //用于增删改;
{
SqlConnection con = new SqlConnection("MySqlCon");
con.Open();
SqlCommand cmd = new SqlCommand();
cmd.Connection = con;
cmd.CommandType = CommandType.Text;
cmd.CommandText = sqlStr;
int iud = 0;
iud = cmd.ExecuteNonQuery();
con.Close();
return iud;
}到此这篇关于C#连接数据库的文章就介绍到这了。希望对大家的学习有所帮助，也希望大家多多支持脚本之家。