在 MySql 中使用 where 子句选择

Question

是否可以从具有特定 ID 的表中选择数据？ 我知道它适用于更新，但是select的代码是什么？

我在 Visual Studios 中使用 c#，我的目标是在 readOnly textboxes 中显示详细信息。

 string corp = 
   @"select corporateName, 
            corporateAddress, 
            corporateContact 
       from corporatemembership 
      where corporateID = CorpID.Text";

Answer 1

这应该这样做

string Command = 
  @"select corporateName, 
           corporateAddress, 
           corporateContact 
      from corporatemembership 
     where corporateID = @CorpID;";

using (MySqlConnection myConnection = new MySqlConnection(ConnectionString))
{
    using (MySqlDataAdapter myDataAdapter = new MySqlDataAdapter(Command, myConnection))
    {
        myDataAdapter.SelectCommand.Parameters.Add(new MySqlParameter("@CorpID", CorpID.Text));
        DataTable dtResult = new DataTable();
        myDataAdapter.Fill(dtResult);
        corporateName.Text = dtResult.Rows[0]["corporateName"];
        corporateAddress.Text = dtResult.Rows[0]["corporateAddress"];
        corporateContact.Text = dtResult.Rows[0]["corporateContact"];
    }
}

也许您应该添加一些错误处理并处理 CorpID 不存在的情况

更新另一种方法

string Command =
        @"select corporateName, 
                 corporateAddress, 
                 corporateContact 
            from corporatemembership 
            where corporateID = @CorpID;";
using (MySqlConnection mConnection = new MySqlConnection(ConnectionString))
{
    mConnection.Open();
    using (MySqlCommand cmd = new MySqlCommand(Command, mConnection))
    {
        cmd.Parameters.Add(new MySqlParameter("@CorpID", CorpID.Text));
        using (MySqlDataReader reader = cmd.ExecuteReader())
        {
            if (reader.Read())
            {
                corporateName.Text = (string)reader["corporateName"];
                corporateAddress.Text = (string)reader["corporateAddress"];
                corporateContact.Text = (string)reader["corporateContact"];
            }
        }
    }
}

Answer 2

是的，有可能，你的sql字符串没问题，除了最后一部分，你将编辑最后一部分

string corp = "从corporatemembership 中选择corporateName、corporateAddress、corporateContact where companyID = " + "'" + CorpID.Text + "'";