java - JTable 从 MySQL 数据库获取值

Question

我需要从数据库中获取所有值并将其放入 JTable 中，填充所有行。 我的代码只将最后一行放入 JTable 中，而错过了所有前面的内容。 有人知道如何从数据库中获取所有值并将它们全部插入到 JTable 中吗？

try{
            Class.forName("com.mysql.jdbc.Driver");
            conn3 = DriverManager.getConnection("jdbc:mysql://localhost/test1?user=me&password=123456");
            stmt3 = conn3.createStatement();
            rs3 = stmt3.executeQuery("SELECT * FROM teams");
            String str1 = null,str2 = null,str3 = null,str4 = null,str5 = null;
            while (rs3.next())
            {
                str1 = rs3.getString(1);
                str2 = rs3.getString(2);
                str3 = rs3.getString(3);
                str4 = rs3.getString(4);
                str5 = rs3.getString(5);
            }

            Object[][] data = {{str1,str2,str3,str4,str5}};
            String[] columnNames = {"id","Name","Players","Point","Position" };
            table = new JTable(data,columnNames);
            table.setCellSelectionEnabled(true);
            table.setColumnSelectionAllowed(true);
            table.setFillsViewportHeight(true);
            table.setSurrendersFocusOnKeystroke(true);
            table.setBounds(10, 321, 297, 143);
            frame.getContentPane().add(table);
            rs3.close();
            stmt3.close();
            conn3.close();
    }
    catch (SQLException se)
    {
        System.out.println( "SQL Exception:" );
           while( se != null )
           {
              System.out.println( "State  : " + se.getSQLState()  );
              System.out.println( "Message: " + se.getMessage()   );
              System.out.println( "Error  : " + se.getErrorCode() );
              se = se.getNextException();
           }
    }
    catch (ClassNotFoundException ex)
    {
           System.out.println("Error: unable to load driver class!");
    }

Answer 1

while (rs3.next())
        {
            str1 = rs3.getString(1);
            str2 = rs3.getString(2);
            str3 = rs3.getString(3);
            str4 = rs3.getString(4);
            str5 = rs3.getString(5);
        }

您正在一次又一次地覆盖相同的变量。您应该改用列表或数组。像这样的东西:

while (rs3.next())
        {
            //Given that all of your str are declared as List<String> strX = new List<String>();
            str1.add(rs3.getString(1));
            str2.add(rs3.getString(2));
            str3.add(rs3.getString(3));
            str4.add(rs3.getString(4)); 
            str5.add(rs3.getString(5));
        }

但要在表中插入 ResultSet，有 plenty of tutorials .

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编辑:如果您不想使用表格模型，您可以更改数据检索的逻辑。您必须向表格提供一个矩阵[行][列]。你是哪几排？您的哪些专栏？

行是结果集的“下一个”，而列是 1 到 5。您需要知道那里有多少行(有点棘手):

if (rs3.next()) {
        rs3.last();
        int rows = rs3.getRow();
    }
rs3.beforeFirst();

现在创建矩阵:

String[][] matrix = new String[rows][4]; //Your Object[][] data.

int index = 0;
while(rs3.next()){
    matrix[i][0] = rs3.getString(1);
    matrix[i][1] = rs3.getString(2);
    matrix[i][2] = rs3.getString(3);
    matrix[i][3] = rs3.getString(4); 
    matrix[i][4] = rs3.getString(5);
    i++;
}
String[] columnNames = {"id","Name","Players","Point","Position" };
table = new JTable(matrix, columnNames);

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有用 另一个有用的(但不是严格要求的)检索对象数据的方法是using customized mappings或更复杂的对象关系映射框架，如 Hibernate .