Select 在 MySql 中使用 where 子句

Question

是否可以从具有特定 ID 的 table 中 select 数据？我知道它适用于 update 但 select 的代码是什么？

我在 Visual Studio 中使用 C#，我的目标是在只读文本框中显示详细信息。

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

Answer 1

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"];
    }
}

也许你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，您的 sql 字符串没问题，除了最后一部分，您将编辑最后一部分

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

Select 在 MySql 中使用 where 子句

Select with where clause in MySql

c#

mysql

select

where

visual-studio-2013