select CONCAT(name, desc) from table;
给出以下错误
ERROR: syntax error at or near "desc" LINE 1: select CONCAT(name, desc) from theme; ^ SQL state: 42601 Character: 21
同一查询在sqlserver，hana和oracle上有效吗？任何帮助将不胜感激
答案 0 :(得分：2)
import com.toedter.calendar.JDateChooser;
import java.awt.EventQueue;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.time.LocalDate;
import java.time.ZoneId;
import java.util.Date;
import javax.swing.JFrame;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
private boolean manualDate;
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JDateChooser dateChooser = new JDateChooser();
dateChooser.addPropertyChangeListener("date", new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (manualDate) {
return;
}
Date newDate = (Date) evt.getNewValue();
Date oldDate = (Date) evt.getOldValue();
if (newDate != null && oldDate != null) {
LocalDate newLD = LocalDate.ofInstant(newDate.toInstant(), ZoneId.systemDefault());
LocalDate oldLD = LocalDate.ofInstant(oldDate.toInstant(), ZoneId.systemDefault());
if (newLD.equals(oldLD)) {
return;
}
}
System.out.println(evt.getPropertyName());
}
});
manualDate = true;
dateChooser.setDate(new Date());
manualDate = false;
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(dateChooser);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
是保留关键字，您必须引用它：
desc如果您密切注意错误消息中的select CONCAT(name, "desc")
from the_table
，它将准确指向^部分，表明这是问题所在，而不是desc函数。