java - How to insert correctly data on MySQL db through JPA when tables are linked with OneToOne relationship -

i have doubt , consequently don't know how proceed correctly. have 3 different tables in figure below. i'm using jpa. here code generated automatically netbeans shows entities. question should persist database? if put user, have automatically persisted phone numbers , client? i'm pretty confused

here code

usercredential user = new usercredential();         user.setusername(username);         user.setpassword(utilbean.hashpassword(password));         user.setemail(email);          client client = new client();         client.setusercredential(user);         client.setname(name);         client.setsurname(surname);         client.setaddress(address);         client.setcity(city);         client.setzipcode(zipcode);         client.setcountry(country);         client.setfidelitypoints(0);          clientphonenumbers phonenumber = new clientphonenumbers();          phonenumber.setusername(username);          if(homenumber != null || !(homenumber.equals("")))         {             phonenumber.setcountrycodehome(areacodehomenumber);             phonenumber.sethome(homenumber);         }          phonenumber.setcountrycodemobile(areacodemobilenumber);         phonenumber.setmobile(mobilenumber);          client.setclientphonenumbers(phonenumber);           em.persist(user); 

user credential

@entity @table(name = "user_credential") @namedqueries( {     @namedquery(name = "usercredential.findall", query = "select u usercredential u") }) public class usercredential implements serializable {     private static final long serialversionuid = 1l;     @id     @basic(optional = false)     @notnull     @size(min = 1, max = 16)     @column(name = "username")     private string username;     // @pattern(regexp="[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?", message="invalid email")//if field contains email address consider using annotation enforce field validation     @basic(optional = false)     @notnull     @size(min = 1, max = 255)     @column(name = "email")     private string email;     @basic(optional = false)     @notnull     @size(min = 1, max = 255)     @column(name = "password")     private string password;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "groupname")     private string groupname;     @column(name = "create_time")     @temporal(temporaltype.timestamp)     private date createtime;     @onetoone(cascade = cascadetype.all, mappedby = "usercredential")     private client client;      public usercredential()     {     }      public usercredential(string username)     {         this.username = username;     }      public usercredential(string username, string email, string password, string groupname)     {         this.username = username;         this.email = email;         this.password = password;         this.groupname = groupname;     }      public string getusername()     {         return username;     }      public void setusername(string username)     {         this.username = username;     }      public string getemail()     {         return email;     }      public void setemail(string email)     {         this.email = email;     }      public string getpassword()     {         return password;     }      public void setpassword(string password)     {         this.password = password;     }      public string getgroupname()     {         return groupname;     }      public void setgroupname(string groupname)     {         this.groupname = groupname;     }      public date getcreatetime()     {         return createtime;     }      public void setcreatetime(date createtime)     {         this.createtime = createtime;     }      public client getclient()     {         return client;     }      public void setclient(client client)     {         this.client = client;     }      @override     public int hashcode()     {         int hash = 0;         hash += (username != null ? username.hashcode() : 0);         return hash;     }      @override     public boolean equals(object object)     {         // todo: warning - method won't work in case id fields not set         if (!(object instanceof usercredential))         {             return false;         }         usercredential other = (usercredential) object;         if ((this.username == null && other.username != null) || (this.username != null && !this.username.equals(other.username)))         {             return false;         }         return true;     }      @override     public string tostring()     {         return "it.volaconoi.entity.usercredential[ username=" + username + " ]";     }  } 

client

@entity @table(name = "client") @namedqueries( {     @namedquery(name = "client.findall", query = "select c client c") }) public class client implements serializable {     private static final long serialversionuid = 1l;     @id     @basic(optional = false)     @notnull     @size(min = 1, max = 16)     @column(name = "username")     private string username;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "name")     private string name;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "surname")     private string surname;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "address")     private string address;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "city")     private string city;     @basic(optional = false)     @notnull     @size(min = 1, max = 10)     @column(name = "zip_code")     private string zipcode;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "country")     private string country;     @basic(optional = false)     @notnull     @column(name = "fidelity_points")     private int fidelitypoints;     @onetoone(cascade = cascadetype.all, mappedby = "client")     private clientphonenumbers clientphonenumbers;     @joincolumn(name = "username", referencedcolumnname = "username", insertable = false, updatable = false)     @onetoone(optional = false)     private usercredential usercredential;     @onetomany(cascade = cascadetype.all, mappedby = "username")     private collection<reservation> reservationcollection;      public client()     {     }      public client(string username)     {         this.username = username;     }      public client(string username, string name, string surname, string address, string city, string zipcode, string country, int fidelitypoints)     {         this.username = username;         this.name = name;         this.surname = surname;         this.address = address;         this.city = city;         this.zipcode = zipcode;         this.country = country;         this.fidelitypoints = fidelitypoints;     }      public string getusername()     {         return username;     }      public void setusername(string username)     {         this.username = username;     }      public string getname()     {         return name;     }      public void setname(string name)     {         this.name = name;     }      public string getsurname()     {         return surname;     }      public void setsurname(string surname)     {         this.surname = surname;     }      public string getaddress()     {         return address;     }      public void setaddress(string address)     {         this.address = address;     }      public string getcity()     {         return city;     }      public void setcity(string city)     {         this.city = city;     }      public string getzipcode()     {         return zipcode;     }      public void setzipcode(string zipcode)     {         this.zipcode = zipcode;     }      public string getcountry()     {         return country;     }      public void setcountry(string country)     {         this.country = country;     }      public int getfidelitypoints()     {         return fidelitypoints;     }      public void setfidelitypoints(int fidelitypoints)     {         this.fidelitypoints = fidelitypoints;     }      public clientphonenumbers getclientphonenumbers()     {         return clientphonenumbers;     }      public void setclientphonenumbers(clientphonenumbers clientphonenumbers)     {         this.clientphonenumbers = clientphonenumbers;     }      public usercredential getusercredential()     {         return usercredential;     }      public void setusercredential(usercredential usercredential)     {         this.usercredential = usercredential;     }      public collection<reservation> getreservationcollection()     {         return reservationcollection;     }      public void setreservationcollection(collection<reservation> reservationcollection)     {         this.reservationcollection = reservationcollection;     }      @override     public int hashcode()     {         int hash = 0;         hash += (username != null ? username.hashcode() : 0);         return hash;     }      @override     public boolean equals(object object)     {         // todo: warning - method won't work in case id fields not set         if (!(object instanceof client))         {             return false;         }         client other = (client) object;         if ((this.username == null && other.username != null) || (this.username != null && !this.username.equals(other.username)))         {             return false;         }         return true;     }      @override     public string tostring()     {         return "it.volaconoi.entity.client[ username=" + username + " ]";     }  } 

** phone numbers **

@entity @table(name = "client_phone_numbers") @namedqueries( {     @namedquery(name = "clientphonenumbers.findall", query = "select c clientphonenumbers c") }) public class clientphonenumbers implements serializable {     private static final long serialversionuid = 1l;     @id     @basic(optional = false)     @notnull     @size(min = 1, max = 16)     @column(name = "username")     private string username;     @size(max = 8)     @column(name = "country_code_home")     private string countrycodehome;     @size(max = 45)     @column(name = "home")     private string home;     @basic(optional = false)     @notnull     @size(min = 1, max = 8)     @column(name = "country_code_mobile")     private string countrycodemobile;     @basic(optional = false)     @notnull     @size(min = 1, max = 45)     @column(name = "mobile")     private string mobile;     @joincolumn(name = "username", referencedcolumnname = "username", insertable = false, updatable = false)     @onetoone(optional = false)     private client client;      public clientphonenumbers()     {     }      public clientphonenumbers(string username)     {         this.username = username;     }      public clientphonenumbers(string username, string countrycodemobile, string mobile)     {         this.username = username;         this.countrycodemobile = countrycodemobile;         this.mobile = mobile;     }      public string getusername()     {         return username;     }      public void setusername(string username)     {         this.username = username;     }      public string getcountrycodehome()     {         return countrycodehome;     }      public void setcountrycodehome(string countrycodehome)     {         this.countrycodehome = countrycodehome;     }      public string gethome()     {         return home;     }      public void sethome(string home)     {         this.home = home;     }      public string getcountrycodemobile()     {         return countrycodemobile;     }      public void setcountrycodemobile(string countrycodemobile)     {         this.countrycodemobile = countrycodemobile;     }      public string getmobile()     {         return mobile;     }      public void setmobile(string mobile)     {         this.mobile = mobile;     }      public client getclient()     {         return client;     }      public void setclient(client client)     {         this.client = client;     }      @override     public int hashcode()     {         int hash = 0;         hash += (username != null ? username.hashcode() : 0);         return hash;     }      @override     public boolean equals(object object)     {         // todo: warning - method won't work in case id fields not set         if (!(object instanceof clientphonenumbers))         {             return false;         }         clientphonenumbers other = (clientphonenumbers) object;         if ((this.username == null && other.username != null) || (this.username != null && !this.username.equals(other.username)))         {             return false;         }         return true;     }      @override     public string tostring()     {         return "it.volaconoi.entity.clientphonenumbers[ username=" + username + " ]";     }  } 

if want persist client well, have call user.setclient(client) before calling persist.