JAVA中的SELECT语句 [英] SELECT statement in JAVA

问题描述

    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上rs = state.executeQuery（） 我用过这个 SQL

                              "SELECT "
                            + "pIDNo AS 'Patient ID',"
                            + "pLName AS 'Last Name'," 
                            + "pFName AS 'First Name',"
                            + "pMI AS 'M.I.',"
                            + "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 'M.I.',"
                            + "pRelationKIN AS 'Relation',"
                            + "pTotalDue AS 'Total Due'"
                            + " FROM dbo.Patients"); 

首先我运行此行（pTotalDue没有达到jTable。）

First I run this line (pTotalDue didn't come up to jTable.)

在我第二次尝试显示它时，我这样做：

And on my second attempt to display it I do this:

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

现在我尝试了这个，我觉得有些不对劲关于我的代码。顺便说一句，这一栏有货币数据类型

Now I tried this one, and I think something's really wrong about my codes. BTW this column has MONEY DATA TYPE

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？

why does it didn't show to my JTable? could anyone tell me what is the problem with my codes?

（给我的答案中的问题）
公共类QueryOnWorkerThread扩展SwingWorker {
private final JTable tableToUpdate;

(Problem in the answer that has given to me) 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: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 );
    }
  }

推荐答案

尝试这个

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});
}

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