GridView select语句没有显示任何内容

Question

<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" DataKeyNames="Match_ID" DataSourceID="SqlDataSource4">
            <Columns>
                <asp:BoundField DataField="Team_name" HeaderText="Team_name" SortExpression="Team_name" />
                <asp:BoundField DataField="Match_ID" HeaderText="Match_ID" InsertVisible="False" ReadOnly="True" SortExpression="Match_ID" />
                <asp:BoundField DataField="Home_team_ID" HeaderText="Home_team_ID" SortExpression="Home_team_ID" />
                <asp:BoundField DataField="Away_team_ID" HeaderText="Away_team_ID" SortExpression="Away_team_ID" />
                <asp:BoundField DataField="Home_team_score" HeaderText="Home_team_score" SortExpression="Home_team_score" />
                <asp:BoundField DataField="Away_team_score" HeaderText="Away_team_score" SortExpression="Away_team_score" />
                <asp:BoundField DataField="Game_date" HeaderText="Game_date" SortExpression="Game_date" />
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource4" runat="server" ConnectionString="<%$ ConnectionStrings:SportsData2ConnectionString %>" SelectCommand="SELECT Team.Team_name, MatchStatistics.Match_ID, MatchStatistics.Home_team_ID, MatchStatistics.Away_team_ID, MatchStatistics.Home_team_score, MatchStatistics.Away_team_score, MatchStatistics.Game_date FROM MatchStatistics INNER JOIN Team ON MatchStatistics.Home_team_ID = Team.Team_ID AND MatchStatistics.Away_team_ID = Team.Team_ID ORDER BY MatchStatistics.Game_date DESC"></asp:SqlDataSource>

我想创建一个显示MatchStatistics内所有记录的GridView。为此，我需要从Team_name表中收集Team。但是，即使MatchStatistics有数据，select语句也不起作用。它有什么问题？

我想要的GridView应该是MatchStatistics的所有内容，主页和远程团队ID已替换为Team_names。与下面类似，但有下拉列表代替主队和客队ID。

Answer 1

我想你想用OR：

FROM MatchStatistics 
INNER JOIN Team 
ON MatchStatistics.Home_team_ID = Team.Team_ID 
**OR** MatchStatistics.Away_team_ID = Team.Team_ID 

实际上，你期待球队与主场比赛相匹配，我想你想找到任何主场或客场球队。

Answer 2

尝试此查询：

SELECT 
    t1.Team_name AS Home_Team_Name,
    t2.Team_name AS Away_Team_Name,
    m.Match_ID, 
    m.Home_team_score, 
    m.Away_team_score, 
    m.Game_date 
FROM MatchStatistics m
INNER JOIN Team t1 ON t1.Team_ID = m.Home_team_ID
INNER JOIN Team t2 ON t2.Team_ID = m.Away_team_ID
ORDER BY m.Game_date DESC

这应该给你团队名而不是teamId。

请记住删除GridView中的第一个列并更新DataFields和SortExpressions以匹配查询中的新列名称：

• Match_ID
• Home_Team_Name
• Away_Team_Name
• Home_team_score
• Away_team_score
• Game_date

您还可以查看sqlfiddle (MySQL)我做的测试。只要知道我在小提琴中使用了一些稍微不同的列名，如果你觉得需要从中复制一些东西。