Help on locking MySQL tables (many can read, but only one can write) Java

Question

Hi there,
I have a question regarding locking of tables so that only one person can write to the file, but many are able to read the files (or tables entities).
I am not sure if I need to lock the tables in my Java code or do I lock the tables within the MySQL syntax. I'm just a little confused on the matter.
This java code is a working prototype of inserting a customer data into the database and that works fine. I just don't know how to implement it so that only one person can update the table at a time.
Here is the Customer.java code that I have written.
Help would be greatly appreciated, thanks so much.
package business;
//~--- non-JDK imports --------------------------------------------------------
import shared.info.CustomerInfo;
//~--- JDK imports ------------------------------------------------------------
import java.sql.*;
* @author
public class Customer {
    static Connection    con  = DBConnection.getConnection();
    private CustomerInfo info = new CustomerInfo();
    private String               customerID;
    private String               firstName;
    private String               lastName;
    private String               email;
    private String               addressID;
    private String               homePhone;
    private String               workPhone;
    private String               unitNum;
    private String               streetNum;
    private String               streetName;
    private String               city;
    private String               provinceState;
    private String               country;
    private String               zipPostalCode;
    public Customer(String id) {
        try {
            PreparedStatement pstmt = con.prepareStatement("SELECT * FROM " +
                    "Customer NATURAL JOIN Address WHERE CustomerID = ?");
            pstmt.setString(1, id);
            ResultSet rs = pstmt.executeQuery();
            while (rs.next()) {
                customerID    = rs.getString("CustomerID");
                firstName     = rs.getString("FirstName");
                lastName      = rs.getString("LastName");
                homePhone     = rs.getString("HomePhone");
                workPhone     = rs.getString("WorkPhone");
                email         = rs.getString("Email");
                city          = rs.getString("City");
                provinceState = rs.getString("ProvinceState");
                country       = rs.getString("Country");
                zipPostalCode = rs.getString("ZipPostalCode");
                unitNum       = rs.getString("UnitNum");
                streetNum     = rs.getString("StreetNum");
                streetName    = rs.getString("StreetName");
                addressID     = rs.getString("AddressId");
        } catch (SQLException e) {
            e.printStackTrace();
        info.setCustomerID(customerID);
        info.setFirstName(firstName);
        info.setLastName(lastName);
        info.setHomePhone(homePhone);
        info.setWorkPhone(workPhone);
        info.setEmail(email);
        info.setCity(city);
        info.setProvinceState(provinceState);
        info.setCountry(country);
        info.setZipPostalCode(zipPostalCode);
        info.setUnitNum(unitNum);
        info.setStreetNum(streetNum);
        info.setStreetName(streetName);
        info.setAddressID(addressID);
    public static void addCustomer(CustomerInfo cust) {
        try {
            int id = -1;
            PreparedStatement pstmt = con.prepareStatement("INSERT INTO Address" +
                    "(UnitNum, StreetNum, StreetName, City, ProvinceState, Country," +
                    " ZipPostalCode) VALUES(?, ?, ?, ?, ?, ?, ?)");
            pstmt.setString(1, cust.getUnitNum());
            pstmt.setString(2, cust.getStreetNum());
            pstmt.setString(3, cust.getStreetName());
            pstmt.setString(4, cust.getCity());
            pstmt.setString(5, cust.getProvinceState());
            pstmt.setString(6, cust.getCountry());
            pstmt.setString(7, cust.getZipPostalCode());
            pstmt.executeUpdate();
            ResultSet rs = pstmt.getGeneratedKeys();
            rs.next();
            id = rs.getInt(1);
            pstmt = con.prepareStatement("INSERT INTO Customer" +
                    "(FirstName, LastName, HomePhone, WorkPhone, Email, AddressID)"
                    + "VALUES(?, ?, ?, ?, ?, ?)");
            pstmt.setString(1, cust.getFirstName());
            pstmt.setString(2, cust.getLastName());
            pstmt.setString(3, cust.getHomePhone());
            pstmt.setString(4, cust.getWorkPhone());
            pstmt.setString(5, cust.getEmail());
            pstmt.setInt(6, id);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
    public void setFirstName(String newName) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Customer"
                                          + " SET FirstName = ? WHERE CustomerID = ?");
            pstmt.setString(1, newName);
            pstmt.setString(2, customerID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        firstName = newName;
    public void setLastName(String newName) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Customer"
                                          + " SET LastName = ? WHERE CustomerID = ?");
            pstmt.setString(1, newName);
            pstmt.setString(2, customerID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        lastName = newName;
    public String getFirstName() {
        return firstName;
    public String getLastName() {
        return lastName;
    public void setHomePhone(String number) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Customer"
                                          + " SET HomePhone = ? WHERE CustomerID = ?");
            pstmt.setString(1, number);
            pstmt.setString(2, customerID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        homePhone = number;
    public String getHomePhone() {
        return homePhone;
    public void setWorkPhone(String number) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Customer"
                                          + " SET WorkPhone = ? WHERE CustomerID = ?");
            pstmt.setString(1, number);
            pstmt.setString(2, customerID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        workPhone = number;
    public String getWorkPhone() {
        return workPhone;
    public void setEmail(String email) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Customer" + " SET Email = ? WHERE CustomerID = ?");
            pstmt.setString(1, email);
            pstmt.setString(2, customerID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        this.email = email;
    public String getEmail() {
        return email;
    public void setUnitNum(String num) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Address" + " SET UnitNum = ? WHERE AddressId = ?");
            pstmt.setString(1, num);
            pstmt.setString(2, addressID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        unitNum = num;
    public String getUnitNum() {
        return unitNum;
    public void setCity(String city) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Address" + " SET City = ? WHERE AddressId = ?");
            pstmt.setString(1, city);
            pstmt.setString(2, addressID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        this.city = city;
    public String getCity() {
        return city;
    public void setStreetNum(String num) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Address" + " SET StreetNum = ? WHERE AddressId = ?");
            pstmt.setString(1, num);
            pstmt.setString(2, addressID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        streetNum = num;
    public String getStreetNum() {
        return streetNum;
    public void setStreetName(String name) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Address"
                                          + " SET StreetName = ? WHERE AddressId = ?");
            pstmt.setString(1, name);
            pstmt.setString(2, addressID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        streetName = name;
    public String getStreetName() {
        return streetName;
    public void setZipPostalCode(String code) {
        try {
            PreparedStatement pstmt = con.prepareStatement("UPDATE Address"
                                          + " SET ZipPostalCode = ? WHERE AddressId = ?");
            pstmt.setString(1, code);
            pstmt.setString(2, addressID);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        zipPostalCode = code;
    public String getZipPostalCode() {
        return zipPostalCode;
    public CustomerInfo getInfo(){
        return info;
    static void deleteCustomer(String customerId) {
        try{
            PreparedStatement pstmt = con.prepareStatement("DELETE FROM Customer" +
                    " WHERE CustomerId = ?");
            pstmt.setString(1, customerId);
            pstmt.executeUpdate();
        }catch(SQLException e){
            e.printStackTrace();
    static void updateCustomer(CustomerInfo custInf) {
        try{
            PreparedStatement pstmt = con.prepareStatement("UPDATE customer" +
                    " SET firstName = ?, SET lastName = ?," +
                    " SET homePhone = ?, SET workPhone = ?, SET email = ?" +
                    " WHERE CustomerId = ?");
            pstmt.setString(1, custInf.getFirstName());
            pstmt.setString(2, custInf.getLastName());
            pstmt.setString(3, custInf.getHomePhone());
            pstmt.setString(4, custInf.getWorkPhone());
            pstmt.setString(5, custInf.getEmail());
            pstmt.setString(6, custInf.getCustomerID());
            pstmt.executeUpdate();
            pstmt = con.prepareStatement("UPDATE address" +
                    " SET unitNum = ?, SET StreetNum = ?, SET StreetName = ?," +
                    " SET city = ?,SET Province = ?,SET country = ?,SET ZipPostalCode = ?" +
                    " WHERE AddressId = ?");
            pstmt.setString(1, custInf.getUnitNum());
            pstmt.setString(2, custInf.getStreetNum());
            pstmt.setString(3, custInf.getStreetName());
            pstmt.setString(4, custInf.getCity());
            pstmt.setString(5, custInf.getProvinceState());
            pstmt.setString(6, custInf.getCountry());
            pstmt.setString(7, custInf.getZipPostalCode());
            pstmt.setString(8, custInf.getAddressID());
            pstmt.executeUpdate();
        }catch(SQLException e){
            e.printStackTrace();
}In addition, here is my customer sql table.
-- Table structure for table `customer`
DROP TABLE IF EXISTS `customer`;
CREATE TABLE `customer` (
`CustomerID` mediumint(9) NOT NULL auto_increment,
`FirstName` varchar(20) NOT NULL,
`LastName` varchar(20) NOT NULL,
`HomePhone` varchar(11) NOT NULL,
`WorkPhone` varchar(11) default NULL,
`Email` varchar(20) NOT NULL,
`AddressID` mediumint(9) default NULL,
PRIMARY KEY (`CustomerID`),
KEY `AddressID` (`AddressID`),
CONSTRAINT `customer_ibfk_1` FOREIGN KEY (`AddressID`) REFERENCES `address` (`AddressID`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
-- Dumping data for table `customer`
LOCK TABLES `customer` WRITE;
/*!40000 ALTER TABLE `customer` DISABLE KEYS */;
/*!40000 ALTER TABLE `customer` ENABLE KEYS */;
UNLOCK TABLES;

Answer 1

to the best of my knowledge, this is something related to the database and not the programming. If you'd want to be the only user to read and edit the table, speicify only one user with that privilege and make it password protected. User must enter the password to write to the tables.