需要帮助找到良好的设计和架构

Question

I want to make an all in one query, or even a two step query that pulls from 3 tables.

Table #1: Games - this table holds a type of game and has a description of the game etc.

Table #2: GameProfiles - this holds an id from the table 'Games', so they both have a GamesId column. This table holds Games won, Games Lost, etc etc

Table #3: Games_WhateverGame - this is not a specific table, there are multiple tables, for instance if I have a game BasketBall, there is going to be a seperate table for it called Games_BasketBall and it has custom columns depending on the game. For example, Basketball would have a column for rebounds. This table would have its own primary key id.

I can easily pull the Games and GameProfiles together using an inner join on their common "GameId" column, but how do I make it so I can also pull 'Games_BasketBall' also in the same query, dynamically depending on the GamesId. I may be structuring this wrong, so I am open to suggestions. I just cant seem to think of a really fluid way of making this work correctly because each game will have different profile entities regardless so I want to make the relations to each table easy so I can pull everything in one query.

This code has the query WITHOUT the relation on to Games_Basketball, I want to be able to pull it all into one reader so it has the information correct.

 using (SqlConnection myConnection = new SqlConnection(myConnectionString))
    {

        myConnection.Open();
        String selectSql = "SELECT * FROM aspnet_GameProfiles INNER JOIN aspnet_Games ON aspnet_GameProfiles.GameId = aspnet_Games.GameId WHERE UserId = @UserId";

        SqlCommand myCommand = new SqlCommand(selectSql, myConnection);
        myCommand.Parameters.AddWithValue("@GameProfile", UserId);


        reader = myCommand.ExecuteReader();
        gameTable.DataSource = reader;
        gameTable.DataBind();
        myConnection.Close();
    }

Answer 1

For yours current shema I would go for something like:

public enum GameType { Basketball, Snooker, ... }

void BindGameData(GameType gameType)
{

[ sql connection code ]

StringBuilder sb = new StringBuilder();
// those constant parts should be stored outside in config file
sb.append("SELECT * FROM aspnet_GameProfiles INNER JOIN aspnet_Games ON aspnet_GameProfiles.GameId = aspnet_Games.GameId "); 
sb.append("INNER JOIN ");
sb.append("aspnet_" + gameType.toString()); // adopt to yours naming pattern
sb.append("ON aspnet_Games.GameId = ");
sb.append("aspnet_" + gameType.toString() + ".GameId");
sb.append("WHERE UserId = @UserId");

String selectSql = sb.toString();

[rest of yours sql connection code]

}

Answer 2

You could also use MARS (Mulitple Active Result Sets) to accomplish your goal. In MARS you use two sqldatareader at the same time.

Here is a small sample:

  SqlDataReader rdrone = null;
  SqlDataReader rdrtwo = null;
  string connectionstring = "server=sugandha;initial catalog = Employeedetail;uid = sa;pwd= sa";MultipleActiveResultSets = true;
  SqlConnection con = new SqlConnection(connectionstring);
  SqlCommand cmdone = new SqlCommand("select * from Employee", con);
  SqlCommand cmdtwo = new SqlCommand("select * from Employeedept", con);
  con.Open();
  rdrone = cmdone.ExecuteReader();
  DataTable dtone = new DataTable();
  dtone.Load(rdrone);
  dataGridView1.DataSource = dtone;
  rdrtwo = cmdtwo.ExecuteReader();
  DataTable dttwo = new DataTable();
  dttwo.Load(rdrtwo);
  dataGridView2.DataSource = dttwo;
  con.Close();

Answer 3

If you want to get all the information for all games at one time, it's not practical to do that in one query. And, you know, the user doesn't want to wait for you to do, say, 135 LEFT JOIN operations to get information from all the game "whatever" tables.

So, even though it's possible, it's not practical, and you really probably don't want to do that anyway. The user isn't likely to want to read through all that data, right?

Show just what the user needs, just when the user needs it. If the user clicks on "basketball", then you can query a view that has already joined the two or three tables you need to display information about the "basketball" game.