Package io.ebean

Interface Database

  • All Known Subinterfaces:
    EbeanServer, SpiServer
    public interface Database
    Provides the API for fetching and saving beans to a particular database.
    Registration with the DB singleton

    When a Database instance is created it can be registered with the DB singleton (see DatabaseConfig.setRegister(boolean)). The DB singleton is essentially a map of Database's that have been registered with it.

    The Database can then be retrieved later via DB.byName(String).

    The 'default' Database

    One Database can be designated as the 'default' or 'primary' Database (see DatabaseConfig.setDefaultServer(boolean). Many methods on DB such as DB.find(Class) etc are actually just a convenient way to call methods on the 'default/primary' Database.

    Constructing a Database

    Database's are constructed by the DatabaseFactory. They can be created programmatically via DatabaseFactory.create(DatabaseConfig) or they can be automatically constructed on demand using configuration information in the application.properties file.

    Example: Get a Database

    

   // Get access to the Human Resources Database
   Database hrDatabase = DB.byName("hr");


   // fetch contact 3 from the HR database
   Contact contact = hrDatabase.find(Contact.class, new Integer(3));

   contact.setStatus("INACTIVE"); ...

   // save the contact back to the HR database
   hrDatabase.save(contact);
    Database vs DB API

    Database provides additional API compared with DB. For example it provides more control over the use of Transactions that is not available in the DB API.

    External Transactions: If you wanted to use transactions created externally to Ebean then Database provides additional methods where you can explicitly pass a transaction (that can be created externally).

    Bypass ThreadLocal Mechanism: If you want to bypass the built in ThreadLocal transaction management you can use the createTransaction() method. Example: a single thread requires more than one transaction.

    See Also:
    DB, DatabaseFactory, DatabaseConfig

    • Method Detail

      • shutdown

        void shutdown()
        Shutdown the Database instance.

      • shutdown

        void shutdown​(boolean shutdownDataSource,
              boolean deregisterDriver)
        Shutdown the Database instance programmatically.

        This method is not normally required. Ebean registers a shutdown hook and shuts down cleanly.

        If the under underlying DataSource is the Ebean implementation then you also have the option of shutting down the DataSource and deregistering the JDBC driver.

        Parameters:
        shutdownDataSource - if true then shutdown the underlying DataSource if it is the Ebean DataSource implementation.
        deregisterDriver - if true then deregister the JDBC driver if it is the Ebean DataSource implementation.

      • getAutoTune

        AutoTune getAutoTune()
        Return AutoTune which is used to control the AutoTune service at runtime.

      • getMetaInfoManager

        MetaInfoManager getMetaInfoManager()
        Return the MetaInfoManager which is used to get meta data from the Database such as query execution statistics.

      • getPlatform

        io.ebean.annotation.Platform getPlatform()
        Return the platform used for this database instance.

        Note many platforms have multiple specific platform types so often we want to get the base platform via Platform.base(). 

        

  Platform platform = database.getPlatform().base();
  if (platform == Platform.MYSQL) {
    // do MySql specific function
  }
        Returns:
        platform for this database instance

      • getBeanState

        BeanState getBeanState​(Object bean)
        Return the BeanState for a given entity bean.

        This will return null if the bean is not an enhanced entity bean.

      • setBeanId

        Object setBeanId​(Object bean,
                 Object id)
        Set the Id value onto the bean converting the type of the id value if necessary.

        For example, if the id value passed in is a String but ought to be a Long or UUID etc then it will automatically be converted.

        Parameters:
        bean - The entity bean to set the id value on.
        id - The id value to set.

      • diff

        Map<String,​ValuePair> diff​(Object newBean,
                                 Object oldBean)
        Return a map of the differences between two objects of the same type.

        When null is passed in for b, then the 'OldValues' of a is used for the difference comparison.

      • createEntityBean

        <T> T createEntityBean​(Class<T> type)
        Create a new instance of T that is an EntityBean.

        Useful if you use BeanPostConstructListeners or @PostConstruct Annotations. In this case you should not use "new Bean...()". Making all bean construtors protected could be a good idea here.

      • update

        <T> UpdateQuery<T> update​(Class<T> beanType)
        Create an Update query to perform a bulk update. 

        

  int rows = database
      .update(Customer.class)
      .set("status", Customer.Status.ACTIVE)
      .set("updtime", new Timestamp(System.currentTimeMillis()))
      .where()
        .gt("id", 1000)
        .update();
        Type Parameters:
        T - The type of entity bean
        Parameters:
        beanType - The type of entity bean to update
        Returns:
        The update query to use

      • createNamedQuery

        <T> Query<T> createNamedQuery​(Class<T> beanType,
                              String namedQuery)
        Create a named query.

        For RawSql the named query is expected to be in ebean.xml.

        Type Parameters:
        T - The type of entity bean
        Parameters:
        beanType - The type of entity bean
        namedQuery - The name of the query
        Returns:
        The query

      • createQuery

        <T> Query<T> createQuery​(Class<T> beanType,
                         String ormQuery)
        Parse the Ebean query language statement returning the query which can then be modified (add expressions, change order by clause, change maxRows, change fetch and select paths etc).

        Example

        

   // Find order additionally fetching the customer, details and details.product name.

   String ormQuery = "fetch customer fetch details fetch details.product (name) where id = :orderId ";

   Query<Order> query = DB.createQuery(Order.class, ormQuery);
   query.setParameter("orderId", 2);

   Order order = query.findOne();

   // This is the same as:

   Order order = DB.find(Order.class)
     .fetch("customer")
     .fetch("details")
     .fetch("detail.product", "name")
     .setId(2)
     .findOne();
        Type Parameters:
        T - The type of the entity bean
        Parameters:
        beanType - The type of bean to fetch
        ormQuery - The Ebean ORM query
        Returns:
        The query with expressions defined as per the parsed query statement

      • find

        <T> Query<T> find​(Class<T> beanType)
        Create a query for a type of entity bean.

        You can use the methods on the Query object to specify fetch paths, predicates, order by, limits etc.

        You then use findList(), findSet(), findMap() and findOne() to execute the query and return the collection or bean.

        Note that a query executed by Query.findList() Query.findSet() etc will execute against the same Database from which is was created. 

        

   // Find order 2 specifying explicitly the parts of the object graph to
   // eagerly fetch. In this case eagerly fetch the associated customer,
   // details and details.product.name

   Order order = database.find(Order.class)
     .fetch("customer")
     .fetch("details")
     .fetch("detail.product", "name")
     .setId(2)
     .findOne();

   // find some new orders ... with firstRow/maxRows
   List<Order> orders =
     database.find(Order.class)
       .where().eq("status", Order.Status.NEW)
       .setFirstRow(20)
       .setMaxRows(10)
       .findList();

      • findNative

        <T> Query<T> findNative​(Class<T> beanType,
                        String nativeSql)
        Create a query using native SQL.

        The native SQL can contain named parameters or positioned parameters. 

        

   String sql = "select c.id, c.name from customer c where c.name like ? order by c.name";

   Query<Customer> query = database.findNative(Customer.class, sql);
   query.setParameter(1, "Rob%");

   List<Customer> customers = query.findList();
        Parameters:
        beanType - The type of entity bean to fetch
        nativeSql - The SQL that can contain named or positioned parameters
        Returns:
        The query to set parameters and execute

      • nextId

        Object nextId​(Class<?> beanType)
        Return the next unique identity value for a given bean type.

        This will only work when a IdGenerator is on the bean such as for beans that use a DB sequence or UUID.

        For DB's supporting getGeneratedKeys and sequences such as Oracle10 you do not need to use this method generally. It is made available for more complex cases where it is useful to get an ID prior to some processing.

      • filter

        <T> Filter<T> filter​(Class<T> beanType)
        Create a filter for sorting and filtering lists of entities locally without going back to the database.

        This produces and returns a new list with the sort and filters applied.

        Refer to Filter for an example of its use.

      • sort

        <T> void sort​(List<T> list,
              String sortByClause)
        Sort the list in memory using the sortByClause which can contain a comma delimited list of property names and keywords asc, desc, nullsHigh and nullsLow.
        • asc - ascending order (which is the default)
        • desc - Descending order
        • nullsHigh - Treat null values as high/large values (which is the default)
        • nullsLow- Treat null values as low/very small values

        If you leave off any keywords the defaults are ascending order and treating nulls as high values.

        Note that the sorting uses a Comparator and Collections.sort(); and does not invoke a DB query. 

        

   // find orders and their customers
   List<Order> list = database.find(Order.class)
     .fetch("customer")
     .order("id")
     .findList();

   // sort by customer name ascending, then by order shipDate
   // ... then by the order status descending
   database.sort(list, "customer.name, shipDate, status desc");

   // sort by customer name descending (with nulls low)
   // ... then by the order id
   database.sort(list, "customer.name desc nullsLow, id");
        Parameters:
        list - the list of entity beans
        sortByClause - the properties to sort the list by

      • createUpdate

        <T> Update<T> createUpdate​(Class<T> beanType,
                           String ormUpdate)
        Create a orm update where you will supply the insert/update or delete statement (rather than using a named one that is already defined using the @NamedUpdates annotation).

        The orm update differs from the sql update in that it you can use the bean name and bean property names rather than table and column names.

        An example: 

        

   // The bean name and properties - "topic","postCount" and "id"

   // will be converted into their associated table and column names
   String updStatement = "update topic set postCount = :pc where id = :id";

   Update<Topic> update = database.createUpdate(Topic.class, updStatement);

   update.set("pc", 9);
   update.set("id", 3);

   int rows = update.execute();
   System.out.println("rows updated:" + rows);

      • findDto

        <T> DtoQuery<T> findDto​(Class<T> dtoType,
                        String sql)
        Create a Query for DTO beans.

        DTO beans are just normal bean like classes with public constructor(s) and setters. They do not need to be registered with DB before use.

        Type Parameters:
        T - The type of the DTO bean.
        Parameters:
        dtoType - The type of the DTO bean the rows will be mapped into.
        sql - The SQL query to execute.

      • createNamedDtoQuery

        <T> DtoQuery<T> createNamedDtoQuery​(Class<T> dtoType,
                                    String namedQuery)
        Create a named Query for DTO beans.

        DTO beans are just normal bean like classes with public constructor(s) and setters. They do not need to be registered with DB before use.

        Type Parameters:
        T - The type of the DTO bean.
        Parameters:
        dtoType - The type of the DTO bean the rows will be mapped into.
        namedQuery - The name of the query

      • sqlUpdate

        SqlUpdate sqlUpdate​(String sql)
        Look to execute a native sql insert update or delete statement.

        Use this to execute a Insert Update or Delete statement. The statement will be native to the database and contain database table and column names.

        See SqlUpdate for example usage.

        Returns:
        The SqlUpdate instance to set parameters and execute

      • register

        void register​(TransactionCallback transactionCallback)
       throws javax.persistence.PersistenceException
        Register a TransactionCallback on the currently active transaction.

        If there is no currently active transaction then a PersistenceException is thrown.

        Parameters:
        transactionCallback - The transaction callback to be registered with the current transaction.
        Throws:
        javax.persistence.PersistenceException - If there is no currently active transaction

      • createTransaction

        Transaction createTransaction()
        Create a new transaction that is not held in TransactionThreadLocal.

        You will want to do this if you want multiple Transactions in a single thread or generally use transactions outside of the TransactionThreadLocal management.

      • createTransaction

        Transaction createTransaction​(io.ebean.annotation.TxIsolation isolation)
        Create a new transaction additionally specifying the isolation level.

        Note that this transaction is NOT stored in a thread local.

      • beginTransaction

        Transaction beginTransaction()
        Start a transaction with 'REQUIRED' semantics.

        With REQUIRED semantics if an active transaction already exists that transaction will be used.

        The transaction is stored in a ThreadLocal variable and typically you only need to use the returned Transaction IF you wish to do things like use batch mode, change the transaction isolation level, use savepoints or log comments to the transaction log.

        Example of using a transaction to span multiple calls to find(), save() etc.

        Using try with resources

        

    // start a transaction (stored in a ThreadLocal)

    try (Transaction txn = database.beginTransaction()) {

 	    Order order = database.find(Order.class, 10);
 	    ...
 	    database.save(order);

 	    txn.commit();
    }

        Using try finally block

        

    // start a transaction (stored in a ThreadLocal)
    Transaction txn = database.beginTransaction();
    try {
 	    Order order = database.find(Order.class,10);

 	    database.save(order);

 	    txn.commit();

    } finally {
 	    txn.end();
    }

        Transaction options

        

     try (Transaction txn = database.beginTransaction()) {

       // explicitly turn on/off JDBC batch use
       txn.setBatchMode(true);
       txn.setBatchSize(50);

       // control flushing when mixing save and queries
       txn.setBatchFlushOnQuery(false);

       // turn off persist cascade if needed
       txn.setPersistCascade(false);

       // for large batch insert processing when we do not
       // ... need the generatedKeys, don't get them
       txn.setBatchGetGeneratedKeys(false);

       // explicitly flush the JDBC batch buffer
       txn.flush();

       ...

       txn.commit();
    }

        If you want to externalise the transaction management then you use createTransaction() and pass the transaction around to the various methods on Database yourself.

      • beginTransaction

        Transaction beginTransaction​(io.ebean.annotation.TxIsolation isolation)
        Start a transaction additionally specifying the isolation level.

      • beginTransaction

        Transaction beginTransaction​(TxScope scope)
        Start a transaction typically specifying REQUIRES_NEW or REQUIRED semantics.

        Note that this provides an try finally alternative to using executeCall(TxScope, Callable) or execute(TxScope, Runnable).

        REQUIRES_NEW example:

        
 // Start a new transaction. If there is a current transaction
 // suspend it until this transaction ends
 try (Transaction txn = database.beginTransaction(TxScope.requiresNew())) {

   ...

   // commit the transaction
   txn.commit();

   // At end this transaction will:
   //  A) will rollback transaction if it has not been committed
   //  B) will restore a previously suspended transaction
 }

        REQUIRED example:

        

 // start a new transaction if there is not a current transaction
 try (Transaction txn = database.beginTransaction(TxScope.required())) {

   ...

   // commit the transaction if it was created or
   // do nothing if there was already a current transaction
   txn.commit();
 }

      • flush

        void flush()
        Flush the JDBC batch on the current transaction.

        This only is useful when JDBC batch is used. Flush occurs automatically when the transaction commits or batch size is reached. This manually flushes the JDBC batch buffer.

        This is the same as currentTransaction().flush().

      • endTransaction

        void endTransaction()
        If the current transaction has already been committed do nothing otherwise rollback the transaction.

        Useful to put in a finally block to ensure the transaction is ended, rather than a rollbackTransaction() in each catch block.

        Code example: 

        

   database.beginTransaction();
   try {
     // do some fetching and or persisting ...

     // commit at the end
     database.commitTransaction();

   } finally {
     // if commit didn't occur then rollback the transaction
     database.endTransaction();
   }

      • refresh

        void refresh​(Object bean)
        Refresh the values of a bean.

        Note that this resets OneToMany and ManyToMany properties so that if they are accessed a lazy load will refresh the many property.

      • refreshMany

        void refreshMany​(Object bean,
                 String propertyName)
        Refresh a many property of an entity bean.
        Parameters:
        bean - the entity bean containing the 'many' property
        propertyName - the 'many' property to be refreshed

      • find

        @Nullable
<T> T find​(Class<T> beanType,
           Object id)
        Find a bean using its unique id. 

        
   // Fetch order 1
   Order order = database.find(Order.class, 1);

        If you want more control over the query then you can use createQuery() and Query.findOne(); 

        
   // ... additionally fetching customer, customer shipping address,
   // order details, and the product associated with each order detail.
   // note: only product id and name is fetch (its a "partial object").
   // note: all other objects use "*" and have all their properties fetched.

   Query<Order> query = database.find(Order.class)
     .setId(1)
     .fetch("customer")
     .fetch("customer.shippingAddress")
     .fetch("details")
     .query();

   // fetch associated products but only fetch their product id and name
   query.fetch("details.product", "name");


   Order order = query.findOne();

   // traverse the object graph...

   Customer customer = order.getCustomer();
   Address shippingAddress = customer.getShippingAddress();
   List<OrderDetail> details = order.getDetails();
   OrderDetail detail0 = details.get(0);
   Product product = detail0.getProduct();
   String productName = product.getName();
        Parameters:
        beanType - the type of entity bean to fetch
        id - the id value

      • getReference

        @Nonnull
<T> T getReference​(Class<T> beanType,
                   Object id)
        Get a reference object.

        This will not perform a query against the database unless some property other that the id property is accessed.

        It is most commonly used to set a 'foreign key' on another bean like: 

        

   Product product = database.getReference(Product.class, 1);

   OrderDetail orderDetail = new OrderDetail();
   // set the product 'foreign key'
   orderDetail.setProduct(product);
   orderDetail.setQuantity(42);
   ...

   database.save(orderDetail);

        Lazy loading characteristics

        

   Product product = database.getReference(Product.class, 1);

   // You can get the id without causing a fetch/lazy load
   Long productId = product.getId();

   // If you try to get any other property a fetch/lazy loading will occur
   // This will cause a query to execute...
   String name = product.getName();
        Parameters:
        beanType - the type of entity bean
        id - the id value

      • extended

        ExtendedServer extended()
        Return the extended API for Database.

        The extended API has the options for executing queries that take an explicit transaction as an argument.

        Typically we only need to use the extended API when we do NOT want to use the usual ThreadLocal based mechanism to obtain the current transaction but instead supply the transaction explicitly.

      • save

        void save​(Object bean)
   throws javax.persistence.OptimisticLockException
        Either Insert or Update the bean depending on its state.

        If there is no current transaction one will be created and committed for you automatically.

        Save can cascade along relationships. For this to happen you need to specify a cascade of CascadeType.ALL or CascadeType.PERSIST on the OneToMany, OneToOne or ManyToMany annotation.

        In this example below the details property has a CascadeType.ALL set so saving an order will also save all its details. 

        {@code
   public class Order { ...
        Throws:
        javax.persistence.OptimisticLockException

      • saveAll

        int saveAll​(Collection<?> beans)
     throws javax.persistence.OptimisticLockException
        Save all the beans in the collection.
        Throws:
        javax.persistence.OptimisticLockException

      • saveAll

        int saveAll​(Object... beans)
     throws javax.persistence.OptimisticLockException
        Save all the beans.
        Throws:
        javax.persistence.OptimisticLockException

      • delete

        boolean delete​(Object bean)
        throws javax.persistence.OptimisticLockException
        Delete the bean.

        This will return true if the bean was deleted successfully or JDBC batch is being used.

        If there is no current transaction one will be created and committed for you automatically.

        If the Bean does not have a version property (or loaded version property) and the bean does not exist then this returns false indicating that nothing was deleted. Note that, if JDBC batch mode is used then this always returns true.

        Throws:
        javax.persistence.OptimisticLockException

      • delete

        boolean delete​(Object bean,
               Transaction transaction)
        throws javax.persistence.OptimisticLockException
        Delete the bean with an explicit transaction.

        This will return true if the bean was deleted successfully or JDBC batch is being used.

        If the Bean does not have a version property (or loaded version property) and the bean does not exist then this returns false indicating that nothing was deleted. However, if JDBC batch mode is used then this always returns true.

        Throws:
        javax.persistence.OptimisticLockException

      • deletePermanent

        boolean deletePermanent​(Object bean)
                 throws javax.persistence.OptimisticLockException
        Delete a bean permanently without soft delete.
        Throws:
        javax.persistence.OptimisticLockException

      • deletePermanent

        boolean deletePermanent​(Object bean,
                        Transaction transaction)
                 throws javax.persistence.OptimisticLockException
        Delete a bean permanently without soft delete using an explicit transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • deleteAllPermanent

        int deleteAllPermanent​(Collection<?> beans)
                throws javax.persistence.OptimisticLockException
        Delete all the beans in the collection permanently without soft delete.
        Throws:
        javax.persistence.OptimisticLockException

      • deleteAllPermanent

        int deleteAllPermanent​(Collection<?> beans,
                       Transaction transaction)
                throws javax.persistence.OptimisticLockException
        Delete all the beans in the collection permanently without soft delete using an explicit transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • delete

        int delete​(Class<?> beanType,
           Object id)
        Delete the bean given its type and id.

      • delete

        int delete​(Class<?> beanType,
           Object id,
           Transaction transaction)
        Delete the bean given its type and id with an explicit transaction.

      • deleteAll

        int deleteAll​(Collection<?> beans)
       throws javax.persistence.OptimisticLockException
        Delete all the beans in the collection.
        Throws:
        javax.persistence.OptimisticLockException

      • deleteAll

        int deleteAll​(Collection<?> beans,
              Transaction transaction)
       throws javax.persistence.OptimisticLockException
        Delete all the beans in the collection using an explicit transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • deleteAll

        int deleteAll​(Class<?> beanType,
              Collection<?> ids)
        Delete several beans given their type and id values.

      • deleteAll

        int deleteAll​(Class<?> beanType,
              Collection<?> ids,
              Transaction transaction)
        Delete several beans given their type and id values with an explicit transaction.

      • execute

        int execute​(SqlUpdate sqlUpdate)
        Execute a Sql Update Delete or Insert statement. This returns the number of rows that where updated, deleted or inserted. If is executed in batch then this returns -1. You can get the actual rowCount after commit() from updateSql.getRowCount().

        If you wish to execute a Sql Select natively then you should use the SqlQuery object or DtoQuery.

        Note that the table modification information is automatically deduced and you do not need to call the DB.externalModification() method when you use this method.

        Example: 

        

   // example that uses 'named' parameters
   String s = "UPDATE f_topic set post_count = :count where id = :id"

   SqlUpdate update = database.createSqlUpdate(s);

   update.setParameter("id", 1);
   update.setParameter("count", 50);

   int modifiedCount = database.execute(update);

   String msg = "There where " + modifiedCount + "rows updated";
        Parameters:
        sqlUpdate - the update sql potentially with bind values
        Returns:
        the number of rows updated or deleted. -1 if executed in batch.
        See Also:
        CallableSql

      • execute

        int execute​(Update<?> update)
        Execute a ORM insert update or delete statement using the current transaction.

        This returns the number of rows that where inserted, updated or deleted.

      • execute

        int execute​(Update<?> update,
            Transaction transaction)
        Execute a ORM insert update or delete statement with an explicit transaction.

      • execute

        int execute​(CallableSql callableSql)
        For making calls to stored procedures.

        Example: 

        

   String sql = "{call sp_order_modify(?,?,?)}";

   CallableSql cs = database.createCallableSql(sql);
   cs.setParameter(1, 27);
   cs.setParameter(2, "SHIPPED");
   cs.registerOut(3, Types.INTEGER);
   cs.execute();

   // read the out parameter
   Integer returnValue = (Integer) cs.getObject(3);

      • externalModification

        void externalModification​(String tableName,
                          boolean inserted,
                          boolean updated,
                          boolean deleted)
        Inform Ebean that tables have been modified externally. These could be the result of from calling a stored procedure, other JDBC calls or external programs including other frameworks.

        If you use database.execute(UpdateSql) then the table modification information is automatically deduced and you do not need to call this method yourself.

        This information is used to invalidate objects out of the cache and potentially text indexes. This information is also automatically broadcast across the cluster.

        If there is a transaction then this information is placed into the current transactions event information. When the transaction is committed this information is registered (with the transaction manager). If this transaction is rolled back then none of the transaction event information registers including the information you put in via this method.

        If there is NO current transaction when you call this method then this information is registered immediately (with the transaction manager).

        Parameters:
        tableName - the name of the table that was modified
        inserted - true if rows where inserted into the table
        updated - true if rows on the table where updated
        deleted - true if rows on the table where deleted

      • find

        <T> T find​(Class<T> beanType,
           Object id,
           Transaction transaction)
        Find a entity bean with an explicit transaction.
        Type Parameters:
        T - the type of entity bean to find
        Parameters:
        beanType - the type of entity bean to find
        id - the bean id value
        transaction - the transaction to use (can be null)

      • save

        void save​(Object bean,
          Transaction transaction)
   throws javax.persistence.OptimisticLockException
        Insert or update a bean with an explicit transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • saveAll

        int saveAll​(Collection<?> beans,
            Transaction transaction)
     throws javax.persistence.OptimisticLockException
        Save all the beans in the collection with an explicit transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • checkUniqueness

        @Nonnull
Set<Property> checkUniqueness​(Object bean)
        This method checks the uniqueness of a bean. I.e. if the save will work. It will return the properties that violates an unique / primary key. This may be done in an UI save action to validate if the user has entered correct values.

        Note: This method queries the DB for uniqueness of all indices, so do not use it in a batch update.

        Note: This checks only the root bean! 

        

   // there is a unique constraint on title

   Document doc = new Document();
   doc.setTitle("One flew over the cuckoo's nest");
   doc.setBody("clashes with doc1");

   Set<Property> properties = DB.checkUniqueness(doc);

   if (properties.isEmpty()) {
     // it is unique ... carry on

   } else {
     // build a user friendly message
     // to return message back to user

     String uniqueProperties = properties.toString();

     StringBuilder msg = new StringBuilder();

     properties.forEach((it)-> {
       Object propertyValue = it.getVal(doc);
       String propertyName = it.getName();
       msg.append(" property["+propertyName+"] value["+propertyValue+"]");
     });

     // uniqueProperties > [title]
     //       custom msg > property[title] value[One flew over the cuckoo's nest]

  }
        Parameters:
        bean - The entity bean to check uniqueness on
        Returns:
        a set of Properties if constraint validation was detected or empty list.

      • markAsDirty

        void markAsDirty​(Object bean)
        Marks the entity bean as dirty.

        This is used so that when a bean that is otherwise unmodified is updated the version property is updated.

        An unmodified bean that is saved or updated is normally skipped and this marks the bean as dirty so that it is not skipped. 

        

 Customer customer = database.find(Customer, id);

 // mark the bean as dirty so that a save() or update() will
 // increment the version property
 database.markAsDirty(customer);
 database.save(customer);

      • update

        void update​(Object bean)
     throws javax.persistence.OptimisticLockException
        Saves the bean using an update. If you know you are updating a bean then it is preferable to use this update() method rather than save().

        Stateless updates: Note that the bean does not have to be previously fetched to call update().You can create a new instance and set some of its properties programmatically for via JSON/XML marshalling etc. This is described as a 'stateless update'.

        Optimistic Locking: Note that if the version property is not set when update() is called then no optimistic locking is performed (internally ConcurrencyMode.NONE is used). 

        

 // A 'stateless update' example
 Customer customer = new Customer();
 customer.setId(7);
 customer.setName("ModifiedNameNoOCC");
 database.update(customer);
        Throws:
        javax.persistence.OptimisticLockException

      • update

        void update​(Object bean,
            Transaction transaction)
     throws javax.persistence.OptimisticLockException
        Update a bean additionally specifying a transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • updateAll

        void updateAll​(Collection<?> beans)
        throws javax.persistence.OptimisticLockException
        Update a collection of beans. If there is no current transaction one is created and used to update all the beans in the collection.
        Throws:
        javax.persistence.OptimisticLockException

      • updateAll

        void updateAll​(Collection<?> beans,
               Transaction transaction)
        throws javax.persistence.OptimisticLockException
        Update a collection of beans with an explicit transaction.
        Throws:
        javax.persistence.OptimisticLockException

      • merge

        void merge​(Object bean)
        Merge the bean using the default merge options (no paths specified, default delete).
        Parameters:
        bean - The bean to merge

      • merge

        void merge​(Object bean,
           MergeOptions options)
        Merge the bean using the given merge options.
        Parameters:
        bean - The bean to merge
        options - The options to control the merge

      • merge

        void merge​(Object bean,
           MergeOptions options,
           Transaction transaction)
        Merge the bean using the given merge options and a transaction.
        Parameters:
        bean - The bean to merge
        options - The options to control the merge

      • insert

        void insert​(Object bean)
        Insert the bean.

        Compared to save() this forces bean to perform an insert rather than trying to decide based on the bean state. As such this is useful when you fetch beans from one database and want to insert them into another database (and you want to explicitly insert them).

      • insertAll

        void insertAll​(Collection<?> beans)
        Insert a collection of beans. If there is no current transaction one is created and used to insert all the beans in the collection.

      • execute

        void execute​(TxScope scope,
             Runnable runnable)
        Execute a Runnable in a Transaction with an explicit scope.

        The scope can control the transaction type, isolation and rollback semantics. 

        

   // set specific transactional scope settings
   TxScope scope = TxScope.requiresNew().setIsolation(TxIsolation.SERIALIZABLE);

   database.execute(scope, new Runnable() {
 	   public void run() {
 		   User u1 = database.find(User.class, 1);
 		   ...
     }
   });

      • execute

        void execute​(Runnable runnable)
        Execute a Runnable in a Transaction with the default scope.

        The default scope runs with REQUIRED and by default will rollback on any exception (checked or runtime). 

        

    database.execute(() -> {

        User u1 = database.find(User.class, 1);
        User u2 = database.find(User.class, 2);

        u1.setName("u1 mod");
        u2.setName("u2 mod");

        u1.save();
        u2.save();
    });

      • executeCall

        <T> T executeCall​(TxScope scope,
                  Callable<T> callable)
        Execute a TxCallable in a Transaction with an explicit scope.

        The scope can control the transaction type, isolation and rollback semantics. 

        

   // set specific transactional scope settings
   TxScope scope = TxScope.requiresNew().setIsolation(TxIsolation.SERIALIZABLE);

   database.executeCall(scope, new Callable<String>() {
 	   public String call() {
 		   User u1 = database.find(User.class, 1);
 		   ...
 		   return u1.getEmail();
     }
   });

      • executeCall

        <T> T executeCall​(Callable<T> callable)
        Execute a TxCallable in a Transaction with the default scope.

        The default scope runs with REQUIRED and by default will rollback on any exception (checked or runtime). 

        

   database.executeCall(new Callable<String>() {
     public String call() {
       User u1 = database.find(User.class, 1);
       User u2 = database.find(User.class, 2);

       u1.setName("u1 mod");
       u2.setName("u2 mod");

       database.save(u1);
       database.save(u2);

       return u1.getEmail();
     }
   });

      • json

        JsonContext json()
        Return the JsonContext for reading/writing JSON.

        This instance is safe to be used concurrently by multiple threads and this method is cheap to call.

        Simple example:

        

     JsonContext json = database.json();
     String jsonOutput = json.toJson(list);
     System.out.println(jsonOutput);

        Using PathProperties:

        

     // specify just the properties we want
     PathProperties paths = PathProperties.parse("name, status, anniversary");

     List<Customer> customers =
       database.find(Customer.class)
         // apply those paths to the query (only fetch what we need)
         .apply(paths)
         .where().ilike("name", "rob%")
         .findList();

     // ... get the json
     JsonContext jsonContext = database.json();
     String json = jsonContext.toJson(customers, paths);
        See Also:
        FetchPath, Query.apply(FetchPath)

      • script

        ScriptRunner script()
        Return a ScriptRunner for running SQL or DDL scripts.

        Intended to use mostly in testing to run seed SQL scripts or truncate table scripts etc.

      • publish

        <T> T publish​(Class<T> beanType,
              Object id,
              Transaction transaction)
        Publish a single bean given its type and id returning the resulting live bean.

        The values are published from the draft to the live bean.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        beanType - the type of the entity bean
        id - the id of the entity bean
        transaction - the transaction the publish process should use (can be null)

      • publish

        <T> T publish​(Class<T> beanType,
              Object id)
        Publish a single bean given its type and id returning the resulting live bean. This will use the current transaction or create one if required.

        The values are published from the draft to the live bean.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        beanType - the type of the entity bean
        id - the id of the entity bean

      • publish

        <T> List<T> publish​(Query<T> query,
                    Transaction transaction)
        Publish the beans that match the query returning the resulting published beans.

        The values are published from the draft beans to the live beans.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        query - the query used to select the draft beans to publish
        transaction - the transaction the publish process should use (can be null)

      • publish

        <T> List<T> publish​(Query<T> query)
        Publish the beans that match the query returning the resulting published beans. This will use the current transaction or create one if required.

        The values are published from the draft beans to the live beans.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        query - the query used to select the draft beans to publish

      • draftRestore

        <T> T draftRestore​(Class<T> beanType,
                   Object id,
                   Transaction transaction)
        Restore the draft bean back to the live state.

        The values from the live beans are set back to the draft bean and the @DraftDirty and @DraftReset properties are reset.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        beanType - the type of the entity bean
        id - the id of the entity bean to restore
        transaction - the transaction the restore process should use (can be null)

      • draftRestore

        <T> T draftRestore​(Class<T> beanType,
                   Object id)
        Restore the draft bean back to the live state.

        The values from the live beans are set back to the draft bean and the @DraftDirty and @DraftReset properties are reset.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        beanType - the type of the entity bean
        id - the id of the entity bean to restore

      • draftRestore

        <T> List<T> draftRestore​(Query<T> query,
                         Transaction transaction)
        Restore the draft beans matching the query back to the live state.

        The values from the live beans are set back to the draft bean and the @DraftDirty and @DraftReset properties are reset.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        query - the query used to select the draft beans to restore
        transaction - the transaction the restore process should use (can be null)

      • draftRestore

        <T> List<T> draftRestore​(Query<T> query)
        Restore the draft beans matching the query back to the live state.

        The values from the live beans are set back to the draft bean and the @DraftDirty and @DraftReset properties are reset.

        Type Parameters:
        T - the type of the entity bean
        Parameters:
        query - the query used to select the draft beans to restore

      • validateQuery

        <T> Set<String> validateQuery​(Query<T> query)
        Returns the set of properties/paths that are unknown (do not map to known properties or paths).

        Validate the query checking the where and orderBy expression paths to confirm if they represent valid properties/path for the given bean type.

      • truncate

        void truncate​(String... tables)
        Truncate all the given tables.

      • truncate

        void truncate​(Class<?>... tables)
        Truncate the base tables for the given bean types.