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How to bind entity to different tables with SpringJPA/SpringBoot

I want to design a system. There are different customers using this system. I need to create the duplicated tables for every customer. For example, I have a table Order, then all of order records for customerA are in table Order_A, as well as customerB data are in table Order_B. I can distinct different customers from session, but how can I let Spring JPA to reflect the RDS table data to Java object?
I know 2 solutions, but both are not satisfied.
Consider to use Mybatis because it supports load SQL from xml file and parameters inside SQL;
Consider to use org.hibernate.EmptyInterceptor. This is my current implement in my project. For every entity, I must define a subclass of it. It can update the SQL before Hibernate's execution.
However, both are not graceful. I prefer the better solution.

Hibernate/JPA - do operations on table only if exists

I am looking for an answer if it is possible or not in hibernate.
What I am trying to achieve is that if a particular table exists in the DB then the application should do all the regular operations with it (which exists in the code - find,save.. etc.).
Else just ignore the table (#Repository) and the fields in the #Entity class, and will skip all the related code.
I have the same question regarding ignoring particular non-existing field of an existing table and the field is annotated with #Column, is it possible to ignore the field if it does not exist in table?
I want to use save method of JPA but which can ignore that field if needed.

That's impossible because with Hibernate you map a Class to table and the table and all the mapped columns MUST exist.
What you are trying to do is dynamic SQL and there you would need to read the database dictonary to check what exsits and generate the code during runtime.

Hibernate create table at runtime

In my database(postgreSQl) is table Person which contains name and password. It is possible to dynamically(at Spring runtime) create new table by using Hibernate? For example I want to create something like single infoTable for every Person (when Person object is created). This table should have name like Person_Id+"infoTable". Is there any way to do that?

Hibernate does offer the mode called EntityMode.MAP that is excellent for unstructured data.
In order to use EntityMode.MAP, you want to create a Map<String, Object> structure where the map keys represent the column names and the object represents the value for the associated map key column. To save such data, you'd use:
session.save( "the_name_of_my_table", theEntityMap );
While this exists, I don't believe this is ideal for your use case though.
As others have suggested, you'd be better off creating an entity that contains a foreign key back to your Person entity and merely manage the multiple rows in a single table. There are numerous database features that can help easily deal with large volumes of data without having to resort to using EntityMode.MAP.

You set hibernate.hbm2ddl.auto=update in hibernate configuration, but think twice before doing so.

Create table if they do NOT exist

Currently there are schema actions that let you recreate tables on each startup, but dropping them obviously means you lose all rows of that table.
In CQL you can make a query like
CREATE TABLE IF NOT EXISTS keyspace.tablename(....)
But I can't find any way of achieving a similar result with spring-data-casssandra, one that would let me start my app for the first time and on without changing anything.
Is there any way to create a table defined in a POJO with #Table ONLY if said table does not already exist?

See DATACASS-219.
I just recently added support for CREATE TABLE IF NOT EXISTS keyspace.tablename (..);. This will be available in SD Cassandra 1.5 M1 (Ingals). I'll consider backing porting this to 1.4 for the 1.4.2.RELEASE.
The only other way to accomplish this for the time being (if not using the 1.5.0.BUILD-SNAPSHOT containing the DATACASS-219 fix) is to set your SchemaAction to NONE and provide your own raw CQL, initialization scripts to the CassandraSessionFactoryBean using the setStartupScripts(:List) method.

LinkedList with Serialization in Java

I'm getting introduced to serialization and ran into some problems when pairing it with LinkedList
Consider i have the following table:
CREATE TABLE JAVA_OBJECTS (
ID BIGINT NOT NULL UNIQUE AUTO_INCREMENT,
OBJ_NAME VARCHAR(50),
OBJ_VALUE BLOB
);
And i'm planning to store 3 object types - so the table may look like so -
ID OBJ_NAME OBJ_VALUE
============================
1 Class1 BLOB
2 Class2 BLOB
3 Class1 BLOB
4 Class3 BLOB
5 Class3 BLOB
And i'll use 3 different LinkedList's to manage these objects..
I've been able to implement LoadFromTable() and StoreIntoTable(Class1 obj1).
My question is - if i change an attribute for a Class2 object in LinkedList<Class2>, how do i effect the change in the DB for this individual item? Also take into account that the order of the elements in LinkedList may change..
Thanks : )
* EDIT
Yes, i understand that i'll have to delete/update a row in my DB table. But how do i keep track of WHICH row to update? I'm only storing the objects in the List, not their respective IDs in the table.

You'll have to store their IDs in the objects you are storing. However, I would suggest not trying to roll your own ORM system, and instead use something like Hibernate.

If you change an attribute in a an object or the order of items. You will have to delete that row and insert the updated list again.

How do i effect the change in the DB for this individual item?
I hope I get you right. The SQL update and delete statements allow you to add a WHERE clause in which you chose the ID of the row to update.
e.g.
UPDATE JAVA_OBJECTS SET OBJ_NAME ="new name" WHERE ID = 2
EDIT:
To prevent problems with your Ids you could wrap you object
class Wrapper {
int dbId;
Object obj;
}
And add them instead of the 'naked' object into your LinkedList

You can use AUTO_INCREMENT attribute for your table and then use the mysql_insert_id() function to retrieve the id assigned to the row added/updated by the last INSERT/UPDATE statement. Along with this maintain a map (eg a HashMap) from the java object to the Id. Using this map you can keep track of which row to delete/update.
Edit: See the answer to this question as well.

I think the real problem here is, that you mix and match different levels of abstraction. By storing serialized Java objects into a relational database as BLOBs you have to consider several drawbacks:
You loose interoperability. Applications written in other languages than Java are not able to read the data back. Even other Java applications have to have the class files of the serialized classes in their classpath.
Changing the class definitions of the stored classes will end up in maintenance nightmares.
You give up the advantages of a relational database. Serialization hides the actual data from the database. So the database is presented only with a black box. You are unable to execute any meaningfull query against the real data. All what you have is the ID and block of bytes.
You have to implement low level data handling by yourself. Actually the database is made to handle your data effectively, but because of serialization you hinder it doing its job. So you are on your own and you are running into that problem right now.
So in most cases you benifit from separation of concerns and using the right tool for a job.
Here are some suggestions:
Separate the internal data handling inside your application from persistent storage. Design your database schema in a way to enable the built-in database features to handle the data efficently. In case of a relational database like MySQL you can choose from different technologies like plain JDBC, object relational mappers like JPA or simple mappers like MyBatis. Separation here means to avoid to contaminate the database with implementation specific concerns.
If you have for example in your Java application a List of Person instances and each Person consists of a name and an age. Then you would represent that list in a relational database as a table consisting of a VARCHAR field for the name and a numeric field for the age and maybe a third field for a unique key. Then the database is able to do what it can do best: managing large amounts of data.
Inside your application you typically separate the persistent layer from the rest of your program containing the code to communicate with the database.
In some use cases a relational database may not be the appropiate tool. Maybe in a single user desktop application with a small set of data it may be the best to simply serialize your Person list into a plain file and read it back at the next start up.
But there exists other alternatives to persist your data. Maybe some kind of object oriented database is the right tool. In particular I have experiences with Fast Objects. As a simplification it is serialization on steroids. There is no need for a layer like JPA or JDBC between your application and your database. You are able to store the class instances directly into the database. But unlike the relational database with its BLOB field, the OODB knows your classes and the actual data and can benefit from that.
Another alternative may be JDBM or Berkeley DB.
So separation of concerns and choosing the right persistence strategy (and using it the right way) is a key concern for the success of your project. But doing it right is hard even for experienced developers.