Exiting While Loop - mysql

Question

I am trying to read values from a MySql database and check whether the id that needs to be updated, already exists in database or not. I have been able to make everything else in the program work except the part of checking database. Here is some of my code:
public void updateStatement() throws SQLException{
try
{
connnectDatabse();
}
catch (ClassNotFoundException e)
{
System.out.println("Could not connect to database..");
}
System.out.println("How many entries would you like to update?");
kb=new Scanner(System.in);
int numEntries = kb.nextInt();
int counter =0;
String newName=null, newDepartment =null;
int newSalary=0, newId =0;
int counterValues =0;
while(counterValues != numEntries){
System.out.println("Please enter 5 to view current entries in database\n");
selectStatement();
int idToUpdate =0;
boolean idVerify =false;
//Check if the user id exists in database or not
while(!(idVerify)){
System.out.println("\nPlease enter the ID of the record to update");
idToUpdate = kb.nextInt();
idFoundInDatabase(idArrayList, idToUpdate);
}
System.out.println("Please choose the number of column to update from below options.\n1.ID\n2.Name\n3.Salary\n4.Department");
int columnToUpdate = kb.nextInt();
switch(columnToUpdate){
case 1:
System.out.println("What will be the new id value for the selected ID?");
newId = kb.nextInt();
query = "update employee set ID = ? where ID = ?";
break;
case 2:
System.out.println("What will be the new name for the selected ID?");
newName = kb.next();
query = "update employee set Name = ? where ID = ?";
break;
case 3:
System.out.println("What will be the new salary for the selected ID?");
newSalary = kb.nextInt();
query = "update employee set Salary = ? where ID = ?";
break;
case 4:
System.out.println("What will be the new department for the selected ID?");
newDepartment = kb.next();
query = "update employee set Department = ? where ID = ?";
break;
default:
System.out.println("Correct option not chosen");
}
PreparedStatement st = conn.prepareStatement(query);
if(columnToUpdate ==1){
st.setInt(1, newId);
st.setInt(2, idToUpdate);
}
else if(columnToUpdate ==2){
st.setString(1, newName);
st.setInt(2, idToUpdate);
}
else if(columnToUpdate ==3){
st.setInt(1, newSalary);
st.setInt(2, idToUpdate);
}
else{
st.setString(1, newDepartment);
st.setInt(2, idToUpdate);
}
//execute the prepared statement
st.executeUpdate();
System.out.println("Record successfully updated..");
counterValues++;
}
}
//Code that I am unable to exit. This is
a separate method outside of updateStatement() method.
ArrayList contains the list of ids that are already in the database. ArrayList has been populated successfully.
public boolean idFoundInDatabase(ArrayList<String> arrayList, int id){
boolean validId = false;
while(validId == true){
String idRead = String.valueOf(id);
for (int i=0; i<arrayList.size(); i++){
String elementRead =arrayList.get(i);
if(elementRead.equals(idRead)){
validId = true;
break;
}
else{
validId= false;
}
}
}
return validId;
}
}
If required I am also posting the lines of code where I get the result set to make the array list of ids.
while(result.next()){
String id =result.getString("ID");
idArrayList.add(id);
if(choice == 1 || choice == 2 || choice == 3 || choice == 4){
resultIs = result.getString(columnName);
System.out.println(resultIs);
}
else{
System.out.println(result.getString("ID")+"\t"+result.getString("Name")+
"\t"+result.getString("Salary")+"\t"+result.getString("Department") );
}
}
Problem is exiting the above idFoundInDatabase method. It identifies if the id which user wants to update is in the database or not. On finding even the correct id which exists in the database, it just keeps on reading the values in array list, instead of going to return statement. Am I also doing something wrong where I call this method? Any help will be appreciated. Have been stuck on it for almost a day now. Have done debugging many many times. I am doing this just to get acquainted with jdbc and parameterized queries, so that I can follow the similar thing in a bigger project.Any help is appreciated. Thank You.

Answer 1

A few things:
Your while loop inside of idFoundInDatabase() is not necessary - one simple iteration through the for loop over arrayList is enough.
You are returning a boolean value from that function, but your calling method does not capture and use it, so idVerify is never being changed from false to true, so your input loop repeats forever.
All you need to do sort that out is change idFoundInDatabase(idArrayList, idToUpdate); to idVerify = idFoundInDatabase(idArrayList, idToUpdate); and then your input loop should successfully terminate when a valid id is found.