[英]Why does JTable only present 1st row of data?
I'm starting to learn how to use databases and was trying to export the data from my h2 database into a JTable. 我开始学习如何使用数据库,并尝试将h2数据库中的数据导出到JTable中。 The table comes up with the correct number of rows, however, only the first row is filled with data.
该表提供了正确的行数,但是,只有第一行填充了数据。 The rest is a blank grid.
其余为空白网格。 I posted some code below for the JTable.
我在下面为JTable发布了一些代码。 If someone needs to see more code, I'll post it.
如果有人需要查看更多代码,我将其发布。
public class Table extends JTable{
public static int rows;
public static String[][] data;
public static String[] columns = {"Author", "Customer", "Date"};
public static void populateTable() throws ClassNotFoundException, SQLException{
//Server is name of the database class
Server server = new Server();
Statement stat = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
ResultSet rs = stat.executeQuery("SELECT * FROM data");
rs.last();
rows = rs.getRow();
rs.beforeFirst();
data = new String[3][rows];
while(rs.next()){
int i = 0;
data[0][i] = rs.getString("Author");
data[1][i] = rs.getString("Customer");
data[2][i] = rs.getString("Date");
System.out.println(rs.getString("Author"));
i = i++;
}
rs.close();
}
}
class MyTableModel extends DefaultTableModel{
String[] columnNames = {"Author", "Customer", "Date"};
MyTableModel() throws ClassNotFoundException, SQLException{
addColumn(columnNames[0]);
addColumn(columnNames[1]);
addColumn(columnNames[2]);
}
@Override
public int getRowCount() {
return rows;
}
@Override
public int getColumnCount() {
return 3;
}
@Override
public String getColumnName(int columnIndex) {
return columnNames[columnIndex];
}
@Override
public boolean isCellEditable(int rowIndex, int columnIndex) {
return false;
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
return data[columnIndex][rowIndex];
}
I'm also able to print to the console all the data, but it just won't show up in the JTable. 我还可以将所有数据打印到控制台,但是不会显示在JTable中。 I have been stuck on this problem for hours but I don't know what I'm doing wrong.
我已经在这个问题上停留了几个小时,但是我不知道自己在做什么错。 Thanks in advance
提前致谢
This statement is a no-op since i
is assigned before it is incremented 此语句是空操作,因为在递增之前已分配了
i
i = i++;
just use 只是使用
i++;
Also initialize i
before entering the loop 在进入循环之前还要初始化
i
You should either use a for loop or declare i outside of your loop. 您应该使用for循环或在循环之外声明i。 As it stands, you are setting all data to row 0 (int i = 0);
就目前而言,您正在将所有数据设置为行0(int i = 0);
while(rs.next()){
int i = 0; // this will run for every row
data[0][i] = rs.getString("Author");
data[1][i] = rs.getString("Customer");
data[2][i] = rs.getString("Date");
System.out.println(rs.getString("Author"));
i = i++;
}
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