【发布时间】:2014-05-12 18:15:38
【问题描述】:
我正在做一个项目,我从选定的 mysql 表中获取数据(要从中获取数据的表由用户选择)。我正在使用以下代码从选定的表中获取数据:
jTextArea1.setText(null);
tableModel.setColumnCount(0);
tableModel.setRowCount(0);
try {
try {
Class.forName("java.sql.DriverManager");
timeget();
jTextArea4.append(now + ": " + "/ Driver name Detected successfully / \n \n");
} catch (ClassNotFoundException e) {
timeget();
jTextArea4.append(now + ": " + "/ Failed in finding Driver \n " + e.getMessage() + " / \n It is recommended that you DO NOT PROCEED ANY FURTHER \n \n");
JOptionPane.showMessageDialog(null, e.getMessage());
}
con = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:" + GlobalParams.portvar + "/" + (String) jList1.getSelectedValue(), "" + GlobalParams.uservar, "" + GlobalParams.passvar);
Statement stmnt = (Statement) con.createStatement();
String query1 = "Use " + GlobalParams.dbvar;
stmnt.executeQuery(query1);
String query2 = "desc " + (String) jList2.getSelectedValue();
ResultSet rs = stmnt.executeQuery(query2);
while (rs.next()) {
fieldo = rs.getString("Field");
jTextArea1.append(fieldo + "\n");
}
tableModel.addColumn(jTextArea1.getText().substring(0, jTextArea1.getText().indexOf("\n")));
Scanner scanner = new Scanner(jTextArea1.getText());
timeget();
jTextArea4.append(now + ": " + "/ Scanning Available feeds from table '" + (String) jList2.getSelectedValue() + "' / \n");
timeget();
jTextArea4.append(now + ": " + "/ Getting feeds from table '" + (String) jList2.getSelectedValue() + "' / \n \n");
if (scanner.hasNextLine()) {
scanner.nextLine();
while (scanner.hasNextLine()) {
//I BELIEVE MY CODE STARTS TO GO SOMEWHERE WRONG HERE BELOW:
String line = scanner.nextLine();
tableModel.addColumn(line);
Statement stmnt2 = (Statement) con.createStatement();
String tdataget = "Select " + line + " from " + (String) jList2.getSelectedValue();
ResultSet rs2 = stmnt2.executeQuery(tdataget);
while (rs2.next()) {
String field = rs2.getString(line);
tableModel.addRow(new Object[]{field});
}
int end = jTextArea1.getLineEndOffset(0);
jTextArea1.replaceRange("", 0, end);
}
}
} catch (SQLException e) {
if (!(e.getMessage().contains("You have an error in your SQL syntax"))) {
JOptionPane.showMessageDialog(this, e.getMessage());
}
} catch (BadLocationException ex) {
JOptionPane.showMessageDialog(this, ex.getMessage());
}
(jList2 是表名的来源,jList1 包含数据库名称)
问题是,例如。如果mysql中的表是这样的->
Col1 | Col2 | Col3 | Col4 | Col5
---------------------------------------------------------
Data1 | Data2 | Data3 | Data4 | Data5
Datab1 | Datab2 | Datab3 | Datab4 | Datab5
在我的框架中,表格是这样的->
Col1 | Col2 | Col3 | Col4 | Col5
---------------------------------------------------------
Data1
Data2
Data3
Data4
Data5
Datab1
Datab2
Datab3
Datab4
Datab5
那么任何人都可以建议我在java中“切换到下一列”的代码吗? 谢谢
【问题讨论】:
-
首先,您是否打算为每个查询获取一列?或者在单个查询中获取所有列?其次,
tableModel.setValueAt(field, row, column);可能比tableModel.addRow()更有用。 -
谢谢,如果有人不想使用外部资源,这是一个很好的工作方法,只需创建一个循环就可以了:D