在 JSP 页面中显示表中的列名和记录

Question

我知道这个问题可能会以多种不同的方式提出，但我有点卡在无法将列名与记录一起显示的代码中。我正在显示记录，但没有显示列名。任何帮助表示赞赏，到目前为止我的代码如下 -

resultSet = statement.executeQuery(sql);
			ResultSetMetaData metadata = resultSet.getMetaData();
			int count = metadata.getColumnCount();
			
		while(resultSet.next())
		{
		%>
		<tr>
		<%
		ArrayList<String> columns = new ArrayList<>();
		for(int i=1; i<=count;i++)
			{ 
		     String name = metadata.getColumnName(i);
			 columns.add(name);
			  %>
				<td>
				<%= resultSet.getString(i)%>
				
                </td>
                <% 
             }
                %>                   
             </tr>
        
		<%
		}
		
		connection.close();
		} catch (Exception e) {
		e.printStackTrace();
		}
		%>
		</table>
		</body>
		</html>		

带有@swati 建议的修改代码。我在尝试之前添加了表格，并在尝试中包含了数组和 for 循环。这是抛出语法和构造函数错误

<table style="width:100%;text-align:left;border-collapse:collapse;background-color:gold;" border="2" bordercolor="Blue">
		<tr style="background-color:yellowgreen;color:white;">
		</tr>
		<%
		try{
			Connection connection = null;
			ResultSet resultSet = null;
			int counter=1;
			Class.forName("oracle.jdbc.driver.OracleDriver");
            connection = DriverManager.getConnection("jdbc:oracle:thin:@DEV:1521:DEV","DEV","DEV");
			Statement statement = connection.createStatement();
			String sql = ("SELECT * FROM tblnm");
			resultSet = statement.executeQuery(sql);
			ResultSetMetaData metadata = resultSet.getMetaData();
			int count = metadata.getColumnCount();
			ArrayList<String> columns = new ArrayList<>(); 
    <table>
    <tr> //row for displaying column names
        <%for(int i=1; i<=count;i++)
            { 
             String name = metadata.getColumnName(i);
             columns.add(name);      
        %>
          <td><%=name%></td> //displaying column name
        <% } %>
    </tr>
     <%
      while(resultSet.next())
        {
     %>
    <tr>  
        //looping through names      
         <% for(int i=1;i<columns.size();i++) { %>
          //get values from particular columns  
            <td><%= resultSet.getString(columns.get(i))%></td>
         <% } %> //closing for loop
    </tr>
       <%
        }
    		
    		connection.close();
    		} catch (Exception e) {
    		e.printStackTrace();
    		}
    		%>
    		</table>
    		</body>
    		</html>	

Answer 1

您的表结构错误。您需要先显示所有列名，然后显示列下的所有行当前您的代码不显示任何列名，因为您没有编写任何代码来执行相同操作。相反，您的代码应该看起来像下面：

resultSet = statement.executeQuery(sql);
 ResultSetMetaData metadata = resultSet.getMetaData();
 int count = metadata.getColumnCount();
 ArrayList<String> columns = new ArrayList<>(); 
    <table>
    <tr> //row for displaying column names
        <%for(int i=1; i<=count;i++)
            { 
             String name = metadata.getColumnName(i);
             columns.add(name);      
        %>
          <td><%=name%></td> //displaying column name
        <% } %>
    </tr>
     <%
      while(resultSet.next())
        {
     %>
    <tr>  
        //looping through names      
         <% for(int i=1;i<columns.size();i++) { %>
          //get values from particular columns  
            <td><%= resultSet.getString(columns.get(i))%></td>
         <% } %> //closing for loop
    </tr>
       <%
        } //closing while loop 
       //other codes put here
       %>
  </table>