DataTable动态增加一列并赋值-调用应用程序配置文件-带存储过程的SqlHelper类

DataTable dt = new DataTable();

增加列：

dt.columns.add("username",Type.GetType("system.String");

dt.columns.add("age",Type.GetType("System.Int32");

赋值：

dt.Rows.add(new object[]{"黄忠",22});

在C#中如何调用应用程序配置文件(app.conifg)中的连接字符串?

如果是connectionStrings，用ConfigurationManager.ConnectionStrings["add的name"].ConnectionString;

如果是appSettings，用ConfigurationManager.AppSettings["add的key"]

带存储过程的SqlHelper类

public static class SqlHelper

{

private readonly static string strcon = ConfigurationManager.ConnectionStrings["sql"].ConnectionString;

public static int ExeucteNonQuery(string sql, CommandType type, params SqlParameter[] pms)

{

using (SqlConnection con = new SqlConnection(strcon))

{

using (SqlCommand cmd = new SqlCommand (sql,con))

{

cmd.CommandType = type;

if (pms != null)

{

cmd.Parameters.AddRange(pms);

}

con.Open();

return cmd.ExecuteNonQuery();

}

}

}

public static object ExecuteScalary(string sql, CommandType type, params SqlParameter[] pms)

{

using (SqlConnection con = new SqlConnection(strcon))

{

using (SqlCommand cmd = new SqlCommand(sql, con))

{

cmd.CommandType = type;

if (pms != null)

{

cmd.Parameters.AddRange(pms);

}

con.Open();

return cmd.ExecuteScalar();

}

}

}

public static SqlDataReader ExecuteReader(string sql, CommandType type, params SqlParameter[] pms)

{

SqlConnection con = new SqlConnection(strcon);

using (SqlCommand cmd = new SqlCommand(sql,con))

{

cmd.CommandType = type;

if (pms != null)

{

cmd.Parameters.AddRange(pms);

}

con.Open();

return cmd.ExecuteReader(CommandBehavior.CloseConnection);

}

}

public static DataTable GetTable(string sql, CommandType type, params SqlParameter[] pms)

{

using (SqlDataAdapter adapter = new SqlDataAdapter(sql,strcon))

{

adapter.SelectCommand.CommandType = type;

if (pms != null)

{

adapter.SelectCommand.Parameters.AddRange(pms);

}

DataTable table = new DataTable();

adapter.Fill(table);

return table;

}

}

}

今天面试，发现自己有太多的东西，都只是一知半解。



为美好生活，无论加艰难，都不能认输。