顺序如下:再web.config中添加数据库的用户名和密码
创建公用类。
//添加进web.config中的账号和密码 /*<connectionStrings> <add name="connString" connectionString="Server=20181109-093025\SQL2008R2;DataBase=SMDBWeb;Uid=sa;Pwd=sa"/> </connectionStrings>*/ //用将用户名和密码赋值给变量 public static readonly string connstring=ConfigurationManger.ConnectionStrings["connstring"].tostring(); //公用的增删改方法 public static void update(string sql) { sqlconnection cnn=new sqlconnection(connstring) sqlcommand cmd=new sqlcommand(sql,cnn); try { cnn.open(); cmd.executeNonquery(); } catch(exception ex) { throw ex; } finally { cnn.close(); } } //只有一个值的查询 public static string selectRead(string sql) { Sqlconnection cnn=new Sqlconnection(connstring); Sqlcommand cmd=new Sqlcommand(sql,cnn); try { cnn.open(); string str=cmd.executeScalar(); } catch(exception ex) { throw ex; } finally { cnn.close(); } } //结果集的查询 //注调用结果集的时候需要加上判断 可用ds.ready()==false 进行判断 public static SqlDataReader GetRead(string sql) { Sqlconnection cnn=new Sqlconnection(connstring); Sqlcommand cmd=new Sqlcmmand(sql,cnn); try { cnn.open(); SqlDataReader ds=cmd.ExecuteReader(CommandBehavior.CloseConnection); return ds; } catch(Exception ex) { conn.close(); throw ex; } }
/// <summary>
/// 用DataAdaPter获取dataset
/// </summary>
/// <param name="sql"></param>
/// <returns></returns>
public static DataSet GetAdapter(string sql)
{
SqlConnection conn = new SqlConnection(connString);
conn.Open();
SqlDataAdapter sqlData = new SqlDataAdapter(sql, conn);
try
{
DataSet ds = new DataSet();
sqlData.Fill(ds);
return ds;
}
catch (Exception ex)
{
return null;
}
}