如何通过asp.net更新SQL Server数据库中的记录

本文关键字：数据库 记录 Server SQL 何通过 asp net 更新 | 更新日期: 2023-09-27 17:54:55

我在asp.net中编写这段代码，但仍然没有在SQL Server数据库中更新记录:

SqlCommand cmd4 = new SqlCommand("Select * from roomdetail", conn);
SqlDataReader dr = cmd4.ExecuteReader();
while (dr.Read())
    SqlCommand cmd3 = new SqlCommand("update [roomdetail] set [rid]=' " +count+1 + " '  where rid = 0 AND roomtype='"+typeRadioButtonList1.SelectedItem.ToString()+        "' ", conn);

如何通过asp.net更新SQL Server数据库中的记录

使用ado.net的正确方法:

var newId = count + 1;
var roomType = typeRadioButtonList1.SelectedItem.ToString();
using (var connection = new SqlConnection("your db connection string here"))
{
        var query = "UPDATE [roomdetail] SET [rid] = @rid WHERE [rid] = 0 AND roomtype = @roomType";
        SqlCommand command = new SqlCommand(query, connection);
        command.Parameters.AddWithValue("@rid", newId);
        command.Parameters.AddWithValue("@roomType", roomType);
        try
        {
            command.Connection.Open();
            command.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            //handle exception
        }
}

您缺少ExecuteNonQuery方法编写下面的代码

SqlCommand cmd4 = new SqlCommand("Select * from roomdetail", conn);
SqlDataReader dr = cmd4.ExecuteReader();
while (dr.Read())
SqlCommand cmd3 = new SqlCommand("update [roomdetail] set [rid]=' " +count+1 + " '  where rid = 0 AND roomtype='"+typeRadioButtonList1.SelectedItem.ToString()+        "' ", conn);
cmd3.executeNonQuery();

假设连接已经打开，在while循环中您将缺少以下语句:

cmd3.ExecuteNonQuery();

您必须执行命令才能更新数据库。

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