Question

需要计算一周中每天记录的数据量

这有什么不对：

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://www.springframework.org/tags" prefix="spring" %>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ page session="true" %>
<html>

<body>
        <nav class="col-lg-5 col-md-5 col-sm-5">
            <ul class="pull-right">
                <li class="purple"><a href="#"><i class="icons icon-user-3"></i> Login</a>
                    <ul id="login-dropdown" class="box-dropdown">
                        <li>
                            <form id="form" action="<c:url value='/j_spring_security_check'/>"  method="POST">
                                <div class="box-wrapper">
                                    <h4>LOGIN</h4>

                                    <div class="iconic-input">
                                        <input type="text" placeholder="Username" name="j_username" id="j_username">
                                        <i class="icons icon-user-3"></i>
                                    </div>
                                    <div class="iconic-input">
                                        <input type="password" placeholder="Password" name="j_password" id="j_password">
                                        <i class="icons icon-lock"></i>
                                    </div>
                                    <input type="checkbox"  id="_spring_security_remember_me" name="_spring_security_remember_me"> <label for="_spring_security_remember_me">Remember me</label>
                                    <br>
                                    <br>
                                    <div class="pull-left">
                                        <input name="submit" type="submit" class="orange" value="Login">
                                    </div>
                                    <div class="pull-right">
                                        <a href="#">Forgot your password?</a>
                                        <br>
                                        <a href="#">Forgot your username?</a>
                                        <br>
                                    </div>
                                    <br class="clearfix">
                                </div>

                                <div class="footer">
                                    <h4 class="pull-left">NEW CUSTOMER?</h4>
                                    <a class="button pull-right" href="create_an_account.html">Create an account</a>
                                </div>
                            </form>
                        </li>
                    </ul>
                </li>
                <li><a href="#"><i class="icons icon-lock"></i> Create an Account</a></li>
            </ul>
        </nav>

        <c:url var="add" value="/displayproducts" ></c:url>
        <form:form action="${add}" commandName="product">
            <table>
                <tr>
                    <td>
                        <form:label path="productname">
                            <spring:message text="productname"/>
                        </form:label>
                    </td>
                    <td>
                        <form:input path="productname"  />
                    </td>
                </tr>
                <tr>
                    <td>
                        <input name="submit" type="submit" value="Submit" />
                    </td>
                </tr>
            </table>
        </form:form>




<c:url var="addAction" value="/user/add" ></c:url>
<form:form action="${addAction}" commandName="user">
<div class="row">

<div class="col-lg-12 col-md-12 col-sm-12 register-account">

<div class="carousel-heading no-margin">
    <h4>Register</h4>
</div>

<div class="page-content">
<div class="row">

    <div class="col-lg-12 col-md-12 col-sm-12">
        <p><strong>Tausch information</strong></p>
    </div>

    <div class="col-lg-4 col-md-4 col-sm-4">
        <p>E-Mail*</p>
    </div>

    <div class="col-lg-8 col-md-8 col-sm-8">
        <form:input type="text" path="email"/>
    </div>

</div>

<div class="row">

    <div class="col-lg-4 col-md-4 col-sm-4">
        <p>Username*</p>
    </div>
    <div class="col-lg-8 col-md-8 col-sm-8">
        <form:input type="text" path="username"/>
    </div>

</div>

<div class="row">

    <div class="col-lg-4 col-md-4 col-sm-4">
        <p>Password</p>
    </div>
    <div class="col-lg-8 col-md-8 col-sm-8">
        <form:input type="password" path="password"/>
    </div>

</div>


<div class="row">
    <div class="col-lg-12 col-md-12 col-sm-12">
        <input class="big" type="submit" value="<spring:message text="Register"/>">
        <input class="big" type="reset" value="Cancel">
    </div>

</div>
</div>
</div>
</form:form>




</body>
</html>

代码未提供所需的输出。

Answer 1

var collection = dtHour.AsEnumerable()
      .GroupBy(item => item.Field<string>("Day Logged"))
      .Select(item => new { DayOfWeek = item.Key, Count = item.Count());

以您想要的方式打印：

Console.WriteLine("Day of week - Count");
foreach(var item in collection)
{
    Console.WriteLine(item.DayOfWeek + " - " + item.Count);
}

使用LINQ编写DataTable的查询

1 个答案: