【发布时间】：2018-09-18 09:45:48
【问题描述】：
嗨，我是初学者，我正在尝试以某种方式创建预订系统，我现在可以检查是否有重复条目，但是如果没有重复条目，它不会将数据插入数据库，但如果我删除了检查功能复制它可以将数据插入数据库。有什么建议吗？我正在尝试解决它，但它仍然无法正常工作。没有错误但没有添加。
private void btnreserveActionPerformed(java.awt.event.ActionEvent evt) {
try {
DB_Operation DB =new DB_Operation();
String cx1,contactnum11,email1,t11,venuee;
String amount1=aval.getText();
String bal1=b1.getText();
cx1=cx.getText();
contactnum11=contactnum1.getText();
email1=email.getText();
t11=t1.getSelectedItem().toString();
venuee=v.getSelectedItem().toString();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String Dateee = sdf.format(dad.getSelectedDate().getTime());
boolean unique;
unique = true;
String c1="8am to 12 pm";
String c3="8am to 5pm";
String c2="1pm to 5 pm";
ResultSet rsa= DB.searchQuery("SELECT * FROM `reserve1` WHERE `Date`='"+Dateee+"'");
if ( cx.getText().trim().length() == 0|| contactnum1.getText().trim().length() == 0||email.getText().trim().length() == 0){
final JPanel panel = new JPanel();
JOptionPane.showMessageDialog(panel, "All fields must be completed", "Error", JOptionPane.ERROR_MESSAGE);
}
else if(rsa.isBeforeFirst()){
while(rsa.next()){
if(rsa.getString("Venue").equalsIgnoreCase(venuee)&&
rsa.getString("Date").equalsIgnoreCase(Dateee)&& rsa.getString("Time").equals(t11)){
JOptionPane.showMessageDialog(null,"Duplicate Resevation!");
unique = false;
}
else if((t11.equals(c3))&&(rsa.getString("Venue").equalsIgnoreCase(venuee)&&
rsa.getString("Date").equalsIgnoreCase(Dateee)&& rsa.getString("Time").equals(c1))){
JOptionPane.showMessageDialog(null,"Half Day Resevation Exist!");
unique = false;
}
else if((t11.equals(c3))&&(rsa.getString("Venue").equalsIgnoreCase(venuee)&&
rsa.getString("Date").equalsIgnoreCase(Dateee)&& rsa.getString("Time").equals(c2))){
JOptionPane.showMessageDialog(null,"Half Day Resevation Exist!");
unique = false;
}
else if(unique=true){
try
{
String url="jdbc:mysql://localhost:3306/reservation?zeroDateTimeBehavior=convertToNull";
String userdb="root";
String passdb="";
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection(url,userdb,passdb);
Statement stmt=(Statement)conn.createStatement();
stmt.executeUpdate ("INSERT INTO `reserve1`( `Customer Name`, `Contact Number`, `Email Address`, `Venue`, `Date`, `Time`, `Price`, `Balance`) "+ "VALUES ("+"\""+cx1+"\""+","+"\""+contactnum11+"\""+","+"\""+email1+"\""+","+"\""+venuee+"\""+","+"\""+Date1+"\""+","+"\""+t11+"\""+","+"\""+amount1+"\""+","+"\""+bal1+"\""+")");
JOptionPane.showMessageDialog(null,"Data Added!");
}
catch( HeadlessException | ClassNotFoundException | SQLException e)
{
JOptionPane.showMessageDialog(null, e.getMessage() ,"Error", 1);
}
}
}
}
} catch (SQLException ex) {
Logger.getLogger(reservation.class.getName()).log(Level.SEVERE,
null, ex);
}
【问题讨论】：
-
能否为您的查询提供结果集：SELECT * FROM
reserve1WHEREDate='"+Dateee+"'" 以及场地e、Dateee 和 t11 的值 -
它会检查所选日期是否在数据库中，以及预订的场地和时间，如果输入的数据与数据库中的日期、场地、时间相同，则会显示“重复预订”消息
-
我认为您将通过 GUI 提供这些值。请显示您传递的值和查询结果。