Hi I am new here and I need some help in populating other jcomboboxes. All I wanted is that if I will select Last name from the first combobox, the other combobox will be populated by First names of patients/persons that has same Lastnames same as the Middlename. I hope you can help me
here's the pic:sample
As of now this is the code that I got to get values from database and put it on the first jcombobox:
public void lastname(){
try{
Connection con = (Connection)DriverManager.getConnection("jdbc:mysql://localhost/javaclinic", "root","");
String sql1 = "select * from patient";
PreparedStatement pst1 = con.prepareStatement(sql1);
ResultSet rs1 = pst1.executeQuery();
while(rs1.next()){
lastn.addItem(rs1.getString("PLastname"));
}
}
catch(SQLException e){
}
}
Modify the sql to search database , if user enter any value like:
String sql1 = "SELECT * FROM patient";
if(lastName.equals(""))
{
sql1 +=" WHERE PLastName = '" + lastName + "'";
}
Related
I'm trying to update some rows using ResultSet. Basically the syntax works as the following:
ResultSet rs = stmt.executeQuery("SELECT * FROM TABLE");
while (rs.next()) {
rs.updateString("something", "something_else");
rs.updateRow();
}
This works fine with simple queries. However, the query I'm trying to execute contains where clause.
For example: SELECT * FROM TABLE WHERE LASTNAME = "A" AND FIRSTNAME = "B"
One solution I can think of is to extract column values from resultset, and then add if-else statement.
For example:
ResultSet rs = stmt.executeQuery("SELECT * FROM TABLE");
while (rs.next()) {
String lastname = rs.getString("lastname");
String firstname = rs.getString("firstname");
if ("A".equals(lastname) && "B".equals(firstname)){
rs.updateString("something", "something_else");
rs.updateRow();
}
}
Is there anything else I can do to solve this issue?
Try this code,
ResultSet rs = stmt.executeQuery("SELECT * FROM TABLE");
while (uprs.next()) {
String lastname = rs.getString("lastname");
String firstname = rs.getString("firstname");
if (lastname.equals("A") && firstname.equals("B")){
rs.updateString("something", "something_else");
rs.updateRow();
}
I am working on a GUI app with MySQL access. When user enters some data in JTextField 'VendorID', I want it to be searched in the database, find the proper line with information and show all the columns in other JtextFields seperately. Actually I wanted this data to be showed in JLabel but unsuccessful, so trying now with JtextFields. Appreciate any help from you.
public void findVendor() {
String vatEntered = vendorID.getText();
try
{
String myDriver = "com.mysql.jdbc.Driver";
String myUrl = "jdbc:mysql://localhost:3306/masterdata_db?autoReconnect=true&useSSL=false";
Class.forName(myDriver);
Connection conn = DriverManager.getConnection(myUrl, "root", "");
Statement st = conn.createStatement();
String check = "SELECT * FROM vendorcreation WHERE VAT = 'vatEntered' ";
ResultSet resultSet = st.executeQuery(check);
boolean status = true;
if(resultSet.next()==status){
nameSelected.setText(resultSet.getString(1));
adressSelected.setText(resultSet.getString(2));
countrySelected.setText(resultSet.getString(3));
vatSelected.setText(resultSet.getString(4));
ptermsSelected.setText(resultSet.getString(5));
conn.close();
}
else {
JOptionPane.showMessageDialog(null, "NO DATA FOUND! FIRST YOU MUST CREATE IT", "Inane error",JOptionPane.ERROR_MESSAGE);
dispose();
new CreateVendor().setVisible(true);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
From what I'm understanding, you're having trouble executing the statement?
You need to set up the statement as following:
String check = "SELECT * FROM vendorcreation WHERE VAT = " +vatEntered ;
But it is better to use a prepared statement instead.
String check = "SELECT * FROM vendorcreation WHERE VAT = ?";
PreparedStatement st = conn.prepareStatement(check);
st.setString(1, vatEntered);
ResultSet resultSet = st.executeQuery();
As for categorizing data, the order seems to depend on the order that the column is in the database. What you can also do is to manually set the result by changing the statement:
String check = "SELECT (column1, column2) FROM vendorcreation WHERE VAT = ?"//etc
where resultSet.getString(1); would be data from column1.
I want to store the password for required ID using java. Everything is working fine except that I am getting this Exception
"SQL Exception thrown: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(Pass_word) set Pass_word = 'pass' where ID = 2' at line 1".
I am getting this exception only in update query but not in select query.I am using Eclipse. Can anyone tell me what I am doing is wrong?
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
public class information {
public static void main(String[] args) {
String password;
ResultSet rs;
String queryString;
int x=1;
try
{
Class.forName("com.mysql.jdbc.Driver");
Connection conn = null;
conn = DriverManager.getConnection("jdbc:mysql://localhost/onlineexam","root", "batch12#nitap");
System.out.print("Database is connected !");
Statement stmt = conn.createStatement();
PreparedStatement pstmt = null;
while(x==1)
{
System.out.println("Press 1 to enter student id");
System.out.println("Press 2 to exit");
Scanner s= new Scanner(System.in);
int choice = s.nextInt();
switch(choice)
{
case 1: System.out.println("Enter the ID of student");
int id = s.nextInt();
queryString = "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID=" +id;
rs= stmt.executeQuery(queryString);
//System.out.println(rs.getInt("ID"));
while(rs.next())
{
if(rs.getInt("ID")== id)
{
String roll = rs.getString("Roll_no");
String date = rs.getString("Date");
String time = rs.getString("Time");
String c_name = rs.getString("Course_name");
String c_code = rs.getString("Course_code");
password pass1= new password(roll,date,time,c_name,c_code);
pass= pass1.passwd();
System.out.println(pass);
queryString =" Update student_reg(Pass_word) set Pass_word = 'pass' where ID = ?";
//queryString= "INSERT INTO student_reg(Password) VALUES ('password') where ID = ?";
//stmt.executeUpdate(queryString);
//PreparedStatemenet pstmt = conn.preparedStatement("INSERT INTO student_reg(Password) VALUES ('password') where ID = ?");
//pstmt.setLong(1, id);
pstmt = conn.prepareStatement(queryString);
pstmt.setInt(1, id);
int numberOfUpdatedRecords = pstmt.executeUpdate();
s.close();
}
}
break;
case 2: x=0;
}
}
if(conn!= null)
{
stmt.close();
pstmt.close();
conn.close();
conn = null;
}
}
catch(ClassNotFoundException cnf)
{
System.out.println("Driver could not be loaded: " + cnf);
}
catch(SQLException sqle)
{
System.out.println("SQL Exception thrown: " + sqle);
}
catch(Exception e)
{
System.out.print("Do not connect to DB - Error:"+e);
}
}
}
Your code has many problem:
queryString = "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID= id";
This line you have condition where but you not set the value yet, you should set
queryString = "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID = " + id;
Better if you take a look at PreparedStatement for prevent SQL Injection as well.
The last one:
queryString= "INSERT INTO student_reg(Password) VALUES ('password') where ID = id";
This line seem you want to update something. Please review it.
queryString = "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID= id";
should be
queryString = "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID = " + id;
This would fix the error, but it would be better to use a PreparedStatement, where the query String looks like "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID = ?", and you pass the id as a parameter.
It is so obvious because you shouldn't include the 'id' in your query string:
queryString = "select ID,Roll_no, Course_name, Course_code, Date,Time from student_reg where ID = " + id;
Very good hint from #spencer: you can not use WHERE clause in your INSERT INTO statement. Probably you wanted to UPDATE a row with that id. Also it is better to do it using PreparedStatemenet to avoid such mistakes:
conn = DriverManager.getConnection("jdbc:mysql://localhost/onlineexam","root", "batch12#nitap");
PreparedStatemenet pstmt = conn.preparedStatement("UPDATE student_reg SET password = 'password' where ID = ?");
pstmt.setLong(1, id);
int numberOfUpdatedRecords = pstmt.executeUpdate();
I suggest you to rename the column name password, because it is a reserved word in mysql, so you may get strange results working with that column name. Change it to some other thing like: pass_word or passwd , ... . As you may know you can use keywords as column names in your queries using some quotes or other things but it is more safe to rename it to another name, just for hint.
if you use this connection without a connection-pool, you may want to close the Statement and the Connection.
Good Luck.
I have 5 or table table to query from \
my syntax i like this
String sql2 = "SELECT * FROM ? WHERE Patient_ID = ?";
pst = conn.prepareStatement(sql2);
System.out.println("SQL before values are set "+sql2);
System.out.println("The values of table/test name recieved in TestPrint stage 1 "+tblName);
System.out.println("The values of test name recieved in TestPrint stage 1 "+key);
// values are outputted correctly but are not getting set in the query
pst.setString(1, tblName);
pst.setLong(2, key);
ResultSet rs2 = pst.executeQuery(sql2);
while(rs2.next()){
String ID = rs2.getString("ID");
jLabel35.setText(ID);
jLabel37.setText(ID);
jLabel38.setText(ID);
// them print command is initiated to print the panel
}
The problem is when i run this i get an error saying ".....you have and error in SQL syntax near ? WHERE Patient_ID = ?"
When i output the sql using system.out.println(sql2);
values are not set in sql2
When you prepare a statement, the database constructs an execution plan, which it cannot do if the table is not there. In other words, placehodlers can only be used for values, not for object names or reserved words. You'd have to rely on Java to construct your string in such a case:
String sql = "SELECT * FROM `" + tblName + "` WHERE Patient_ID = ?";
pst = conn.prepareStatement(sql);
pst.setLong(1, key);
ResultSet rs = pst.executeQuery();
String sqlStatment = "SELECT * FROM " + tableName + " WHERE Patient_ID = ?";
PreparedStatement preparedStatement = conn.prepareStatement(sqlStatment);
preparedStatement.setint(1, patientId);
ResultSet resultSet = preparedStatement.executeQuery();
public void getByIdEmployer() throws SQLException {
Connection con = null;
try {
con = jdbcUtil.connectionDtls();
PreparedStatement ptst = con.prepareStatement(getById);
ptst.setInt(1, 4);
ResultSet res = ptst.executeQuery();
while (res.next()) {
int empid = res.getInt(1);
System.out.println(empid);
String name = res.getString(2);
System.out.println(name);
int salary = res.getInt(3);
System.out.println(salary);
String location = res.getString(4);
System.out.println(location);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
con.close();
}
}
I have a database with the following layout
databasename:macfast
table name:users
columns
id,
user_name,
password,
fullName
I want to retrieve all the values from the column user_name and check each values with another one string which is already retrieved from a TEXTFIELD.But I can't(NullpointerException). Please help me.
public void deleteFclty() {
PreparedStatement stmt = null;
ResultSet rs = null;
String username=removeText.getText();
String qry = "SELECT user_name From users ";
try {
stmt = (PreparedStatement) connection.prepareStatement(qry);
rs = stmt.executeQuery();
while (rs.next()) {
String check=(rs.getString("user_name"));
System.out.println(check);
if(check.equals(username)){
Util.showErrorMessageDialog("EQUAL");
}else{
Util.showErrorMessageDialog("NOT EQUAL");
}
}
}catch (SQLException ex) {
Logger.getLogger(RemoveFaculty.class.getName()).log(Level.SEVERE, null, ex);
}
}
Problem is with the prepared statement (you don't put id into statement, which should be there instead of question mark).
Also I would recommend to do condition as "username.equals(check)", that can prevent null pointer exception.
"SELECT user_name From users where id=?"
This query has a parameter and you're not setting any value to it. Use PreparedStatement#setInt() or similar to set it, e.g.:
stmt.setInt(1, 1);
The problem is with PreparedStatement as you are using Question mark ? in your query for that you have to set the Id value.
String qry = "SELECT user_name From users where id=?";
stmt = (PreparedStatement) connection.prepareStatement(qry);
stmt.setInt(1,1001);
rs = stmt.executeQuery();
For your question in comment below:
List<String> values = new ArrayList();
while (rs.next()) {
values.add(0,rs.getString(<>))
}
// here do whatever you want to do...
// for example
for ( String value: values )
{
// check if value == TEXTFIELD
// if true then do something..
// else don't do anything
}