C#MySQL问题与where子句 [英] c# Mysql problem with where clause

问题描述

我们可以在Windows C#中使用带有C#对象中参数的"where"子句吗? 用于填充datagridview
例如:

Can we use in windows c# form the "where" clause with the parameter from object in c#
for fill a datagridview
example :

SELECT         Value, IdCategory, CreateDate, Description, IdUser
FROM            profit
WHERE        (IdUser = USER)

其中"USER"在c#中为变量



谢谢！

where "USER" is variable in c#



Thank you!

推荐答案

在此处开始 [ ^ ].

您的字符串看起来像这样:

Your string is going to look something like this:

String query = "SELECT Value, IdCategory, CreateDate, Description, IdUser FROM"
  + " profit WHERE IdUser = '" + USER + "'";

确保像我一样在用户变量周围添加单引号.

然后，您将需要执行以下操作:

Make sure you add the single quotes around your user variable like I did.

Then you will want to do something like:

// your connection (conn) has been made at this point
using(MySqlCommand cmd = new MySqlCommand(query, conn))
{
  cmd.CommandText = query;
  MySqlDataReader reader = cmd.ExecuteReader();

  while(reader.Read())
  {
    // assign results to a variable, probably an array of strings
    // using reader["Value"], reader["IdCategory"], etc...
  }

  reader.Close();
  conn.Close();
}

这是假定您正在使用MySql Connect/NET，因为尚未指定.我基本上只是在评论中给出的链接中提供了文章的简化版本.这是一个很好的很好的例子-在我给你的东西和那篇文章之间，你应该可以完成这项工作.

再次是链接:
将C#连接到MySQL [

This is assuming you''re using MySql Connect/NET, since you haven''t specified. I have basically just provided a simplified version of the article in the link I gave in the comments. It''s a good pretty good example - between what I''ve given you and that article you should be able to get this done.

Here''s the link again:
Connect C# to MySQL[^]

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