59 | How to check if an entity exists in a Database without loading it?How to check if an entity exists in a Database without loading it? |
59 | Source control of databaseSource control of database |
59 | Handling a case of searching an empty databaseHandling a case of searching an empty database |
59 | How do I Remove an entity from the Database ?How do I Remove an entity from the Database ? |
59 | database migrationdatabase migration |
11 | FROM clause (JPQL / Criteria API) the database. A query identification variable is similar to a variable of a Java enhanced for loop in ... identification variables that iterate over all the database objects of a specific entity class ... over all the Country objects in the database: SELECT c FROM Country AS c The AS keyword is optional |
11 | DELETE Queries in JPA/JPQLAs explained in chapter 2, entity objects can be deleted from the database by: Retrieving ... . Applying changes to the database by calling the commit method. JPQL DELETE queries provide ... the database, DELETE queries do not retrieve data from the database, but when executed, delete specified |
11 | JPA Entity Fields that do not participate in persistence and their values are never stored in the database (similar ... only transient (non persistent) entity fields with no real content to be stored in the database. Persistent ... otherwise (e.g. by using the @Transient annotation). Storing an entity object in the database does not |
2 | Step 3: Add a Main Class the database: Right click the tutorial package in the [Package Explorer] window and select New > Class ... void main(String[] args) { // Open a database connection // (create a new database ... .createEntityManager(); // Store 1000 Point objects in the database: em.getTransaction().begin |
1 | ObjectDB 1.0 ManualWelcome to the ObjectDB for Java/JDO Developer's Guide. Here you can learn how to develop database applications using ObjectDB and JDO (Java Data Objects), the revolutionary database programming ... basic database programming using ObjectDB. Subsequent chapters contain detailed instructions |
