How can I convert a schema that I have in Sql Workbench to Java entities for Hibernate?
Is there an easy way?
I would first generate the SQL script from MySQL WorkBench, then physically create the schema in a local database instance.
You can then generate the Hibernate entities direct from the database.
Plenty of guides online for this last step. E.g. http://www.mkyong.com/hibernate/how-to-generate-code-with-hibernate-tools/
Related
Generally we generate tables from Hibernate JPA to Database, but however i want to generate reverse, i.e from Database to Entity (from table to pojo).
Can you please suggest solution for:
is it possible?
is it recommended(if you have near about 1000 table)?
or should I go manually by creating POJO.
(I am using Microsoft SqlServer as DB and Spring boot (STS) in back end)
Thanks in Advance!
I am new in the hibernate world. My project task is to represent xml result from the SQL database. To do so, first step, I am trying to generate POJOs and mapping xml from my db by using hibernate tools auto generating feature. When, i am trying to generate a simple database (2/3 tables) its working fine.
But while i trying to convert my real database, which has 28 tables within different table relationships. Then i am facing the below problem. Not able to connect the database tables. Hibernate tools configuration showing this terrible message.(Foreign key name (fk_p_einheit) mapped to different tables! previous: org.hibernate.mapping.Table(public.einheit_quelle) current:org.hibernate.mapping.Table(public.spalten)
I checked google to get the solution but not get any proper solution related to eclipse IDE. Just got one BUG report from NetBeans site(https://netbeans.org/bugzilla/show_bug.cgi?id=205863).
My setup configuration is:eclipse-jee-luna-SR1-win32-x86_64, postgres (sql 9.1-901.jdbc4) and hibernate core (4.3.5.Final) with maven project and hibernate tools.
Any one please help me.
You need an object model that maps all of those 28 tables and relationships. Do you have one? If not, why are you using Hibernate?
You can ask Hibernate to generate an object model for you from the schema. Try it.
Why are you using all these unknown technologies (Hibernate, Eclipse, etc.) to do something simple?
If you're thinking in terms of tables and columns, and not objects, I'd say you'd be better off writing JDBC and straight SQL. ORM tools aren't for you.
This is something of a noob question, so please bear with me.
I'm building a Java web app which is deployed on JBoss. Part of the functionality is populating a MySQL DB with data from an Excel spreadsheet. This can be achieved in 2 ways:
Using JExcel / Apache POI to parse the spreadsheet data and creating Entity "beans" which are then persisted to the DB.
Using scripts to convert the spreadsheet to csv files and then load the csv files into the DB.
My question is: If I choose the scripting / csv route, can I still use JPQL to query the DB or will I have to resort to native SQL queries in the Java code?
JPQL can be used to query table independently from method that was used to populate table. Data stored to table is not aware of with which method it was inserted.
JPA is not notified about changes made to data via script, but in typical use case with no additional caches and transaction-scoped PersistenceContext that is not the issue, because query will hit the database and deliver fresh data.
I need a tool for converting database tables to entity java files for hibernate.
There are 20 tables (mysql) and I don't want to copy table's column name to my Java file and so on.
Any suggestions ?
Thanks.
Hibernate Tools.
Keep in mind that entity classes / mappings that Database Reverse Engineering tool will generate may not be ideal (depending on complexity of your database) and you'll have to manually update them.
Take a look at this question as well.
Eclipse DALI, Netbeans jpa-plugin and Oracle JDevelopper.
If you have sql schema, you can use https://converter.aldoraweb.com to convert it
I got a new project from my teacher to convert database to another. How can I convert a MS SQL database into MySQL using Java?
You will want to keep in mind that there are two logical steps regardless of the Programming environment. Firstly, you will want to map the schema of the database to an equivalent schema in the target database. This means mapping data types and constraints. Sometimes there are cases where it is simply not possible. Secondly, mapping the data from one database to the other. Timestamps and date formats must be equivalent for example. Hope that helps you to get started.
How can I convert a MS SQL database into MYSQL using JAVA
Dump it ( from MSSQL) and execute the result in Mysql.
With a question like that it's the best answer you can give
You could also try to use the hibernate tools to create a mapping to the MS SQL tables. Then use hibernate again with the created mapping to create the tables in MySQL.
Look at the various metadata classes in JDBC:
java.sql.DatabaseMetaData
java.sql.ResultSetMetaData
These will allow you to get the structure from the MSSQL DB. You need to do a little experimentation as, if memory serves, what gets returned in the metadata can vary from database to database.
Once you've worked out how to get the metadata from the MSSQL DB you need to convert that into SQL commands to recreate the structure in the MySQL DB.
Then with the structure in place you can start copying the data between the two by creating insert queries that run against the MySQL DB from querying the contents of the MSSQL DB. You'll need to do this in the correct order so that the referential integrity isn't violated which again you'll be able to determine from the metadata.
It's an interesting academic exercise but in the real-world you'd use an Extract-Transform-Load (ETL) tool.