JAVA中的SELECT语句

public void search() throws Exception{ Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); String url = "jdbc:odbc:******"; String user = "*****"; String pass = "*****"; Connection con = DriverManager.getConnection(url, user, pass); Statement state = con.createStatement(); ResultSet rs = state.executeQuery(""); ResultSetMetaData rsmetadata = rs.getMetaData(); int columns = rsmetadata.getColumnCount(); DefaultTableModel dtm = new DefaultTableModel(); Vector column_name = new Vector(); Vector data_rows = new Vector(); for (int i=1; i<columns;i++){ column_name.addElement(rsmetadata.getColumnName(i)); } dtm.setColumnIdentifiers(column_name); while(rs.next()){ data_rows = new Vector(); for (int j=1; j<columns; j++){ data_rows.addElement(rs.getString(j)); } dtm.addRow(data_rows); } tblPatient.setModel(dtm); } 

在我的ResultSet rs = state.executeQuery()我使用了这个SQL

  "SELECT " + "pIDNo AS 'Patient ID'," + "pLName AS 'Last Name'," + "pFName AS 'First Name'," + "pMI AS 'MI'," + "pSex AS 'Sex'," + "pStatus AS 'Status'," + "pTelNo AS 'Contact No.'," + "pDocID AS 'Doctor ID'," + "pAddr AS 'St. No.'," + "pStreet AS 'St. Name'," + "pBarangay AS 'Barangay'," + "pCity AS 'City'," + " pProvince AS 'Province'," + " pLNameKIN AS 'Last Name'," + "pFNameKIN AS 'First Name'," + "pMIKIN AS 'MI'," + "pRelationKIN AS 'Relation'," + "pTotalDue AS 'Total Due'" + " FROM dbo.Patients"); 

首先我运行这一行（pTotalDue没有达到jTable。）

在我第二次尝试显示它时，我这样做：

 "SELECT pTotalDue AS 'Total Due' FROM dbo.Patients" 

现在我尝试了这个，我认为我的代码确实存在问题。 BTW此栏有货币数据类型

为什么它没有显示给我的JTable ？ 谁能告诉我我的代码有什么问题？

（给出的答案中的问题）公共类QueryOnWorkerThread扩展了SwingWorker {private final JTable tableToUpdate;

  public QueryOnWorkerThread( JTable aTableToUpdate ) { tableToUpdate = aTableToUpdate; } @Override protected TableModel doInBackground() throws Exception { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); String url = "jdbc:odbc:OJT_dsn"; String user = "sa"; String pass = ""; Connection con = DriverManager.getConnection( url, user, pass ); Statement state = con.createStatement(); ResultSet rs = state.executeQuery(""); ResultSetMetaData rsmetadata = rs.getMetaData(); int columns = rsmetadata.getColumnCount(); DefaultTableModel dtm = new DefaultTableModel(); Vector column_name = new Vector(); Vector data_rows; //note the <= check iso the < check (as the count starts at index 1) for (int i=1; i<=columns;i++){ column_name.addElement(rsmetadata.getColumnName(i)); } dtm.setColumnIdentifiers(column_name); while(rs.next()){ data_rows = new Vector(); //note the <= check iso the < check (as the count starts at index 1) for (int j=1; j<=columns; j++){ data_rows.addElement(rs.getString(j)); } dtm.addRow(data_rows); } return dtm; } `@Override <<<<<<<<<<<<<<<<<<<<< I have a problem here it says : done() in javaapplication25.SearchPatient.QueryWorkerThread cannot override done() in javax.swing.SwingWorker overriden method does not throw java.lang.Exception , what does it mean sir?` protected void done() throws Exception{ //this method runs on the EDT, so it is safe to update our table here try { tableToUpdate.setModel( get() ); } catch ( InterruptedException e ) { throw new RuntimeException( e ); } catch ( ExecutionException e ) { throw new RuntimeException( e ); } } 

Answer 1

试试这个

 DefaultTableModel dtm=(DefaultTableModel)table.getModel(); for (int i = dtm.getRowCount() - 1; i > -1; i--) { dtm.removeRow(i); } Connection con = DriverManager.getConnection(url, user, pass); Statement state = con.createStatement(); ResultSet rs = state.executeQuery("Your SQL Query"); while(rs.next()) { String str1=rs.getString(1); String str2=rs.getString(2); String str3=rs.getString(3); String str4=rs.getString(4); String str5=rs.getString(5); : : : dtm.addRow(new Object[]{str1,str2,str3,str4,str5}); } 

Answer 2

在循环中，退出条件是

 j 

这意味着最后一列永远不会被恢复。 尝试这个insted：

 for (int j=1; j<=columns; j++) 

Answer 3

你的最后一列没有出现的事实可能与你的循环语句有关，正如@Joan已经指出的那样。

但是此代码存在更多问题。 您应该只更新Event Dispatch Thread上的Swing组件，并且在该Thread上您不应该执行长时间运行的操作。 简而言之，混合SQL查询和JTable更新不应该发生在同一个线程上。 有关详细信息，请参阅Swutch中的Concurrency指南。

使用SwingWorker可以解决此问题：

 public class QueryOnWorkerThread extends SwingWorker{ private final JTable tableToUpdate; public QueryOnWorkerThread( JTable aTableToUpdate ) { tableToUpdate = aTableToUpdate; } @Override protected TableModel doInBackground() throws Exception { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); String url = "jdbc:odbc:******"; String user = "*****"; String pass = "*****"; Connection con = DriverManager.getConnection( url, user, pass ); Statement state = con.createStatement(); ResultSet rs = state.executeQuery(""); ResultSetMetaData rsmetadata = rs.getMetaData(); int columns = rsmetadata.getColumnCount(); DefaultTableModel dtm = new DefaultTableModel(); Vector column_name = new Vector(); Vector data_rows; //note the <= check iso the < check (as the count starts at index 1) for (int i=1; i<=columns;i++){ column_name.addElement(rsmetadata.getColumnName(i)); } dtm.setColumnIdentifiers(column_name); while(rs.next()){ data_rows = new Vector(); //note the <= check iso the < check (as the count starts at index 1) for (int j=1; j<=columns; j++){ data_rows.addElement(rs.getString(j)); } dtm.addRow(data_rows); } return dtm; } @Override protected void done() { //this method runs on the EDT, so it is safe to update our table here try { tableToUpdate.setModel( get() ); } catch ( InterruptedException e ) { throw new RuntimeException( e ); } catch ( ExecutionException e ) { throw new RuntimeException( e ); } } } 

可以通过调用启动SwingWorker

 QueryOnWorkerThread worker = new QueryOnWorkerThread( tblPatient ); worker.execute(); 

请注意我是如何更改代码中的循环的

Answer 4

尝试通过ResultSet.getBigDecimal()而不是通过ResultSet.getString()获取该列。 然后将检索到的BigDecimal.toPlainString()放入表格单元格中。

例：

 data_rows.addElement(rs.getBigDecimal("pTotalDue").toPlainString());//Assuming your select returns a pTotalDue Column (eg SELECT pTotalDue,... FROM ...) 

Answer 5

尝试使用TableCellRenderer。

实现渲染器并使用您希望的表单中的Money Type渲染列。

此致，HL