org.hrorm

Interface Dao<T>

Type Parameters:

T - The type of the data to be persisted.

All Known Implementing Classes:

DaoImpl

public interface Dao<T>

A Dao is an interface that allows basic CRUD operations to be performed. Using a Dao, you can insert, select, update, and delete records.

Method Summary

Modifier and Type	Method and Description
void	atomicDelete(T item) Run a delete statement in the database.
long	atomicInsert(T item) Insert a record into the database within a transaction that is managed within the Dao.
void	atomicUpdate(T item) Run an update statement to change the values in the database associated with an existing record.
void	delete(T item) Run a delete statement in the database.
long	insert(T item) Insert a record into the database.
T	select(long id) Read a record from the database.
List<T>	selectAll() Read all the records in the database of type T.
T	selectByColumns(T item, String... columnNames) Select a single record from the database by some search criteria.
List<T>	selectMany(List<Long> ids) Read several records from the database.
List<T>	selectManyByColumns(T item, String... columnNames) Select multiple records from the database by some search criteria.
void	update(T item) Run an update statement to change the values in the database associated with an existing record.

Method Detail

insert

long insert(T item)

Insert a record into the database.

Parameters:

item - The instance to be inserted.

Returns:

The newly issued primary key of the record.

update

void update(T item)

Run an update statement to change the values in the database associated with an existing record. Updates are applied by primary key.

Parameters:

item - An instance of the class with a populated primary key field and updated field values.

delete

void delete(T item)

Run a delete statement in the database. Deletion is done by primary key.

Parameters:

item - An instance of type T with a populated primary key.

select

T select(long id)

Read a record from the database.

Parameters:

id - The primary key of the record desired.

Returns:

The populated instance of type T.

selectMany

List<T> selectMany(List<Long> ids)

Read several records from the database.

Parameters:

ids - The primary keys of the records desired.

Returns:

A list of populated instances of type T.

selectAll

List<T> selectAll()

Read all the records in the database of type T.

Returns:

A list of populated instances of type T.

selectByColumns

T selectByColumns(T item,
                  String... columnNames)

Select a single record from the database by some search criteria. If multiple records are found that match the passed item, an exception will be thrown.

Parameters:

item - An instance of type T with populated values corresponding to the column names to select by.

columnNames - The names of the database columns

Returns:

The populated instance of type T with matching values with the passed item for the indicated columnNames.

selectManyByColumns

List<T> selectManyByColumns(T item,
                            String... columnNames)

Select multiple records from the database by some search criteria.

Parameters:

item - An instance of type T with populated values corresponding to the column names to select by.

columnNames - The names of the database columns

Returns:

The populated instances of type T with matching values with the passed item for the indicated columnNames.

atomicInsert

long atomicInsert(T item)

Insert a record into the database within a transaction that is managed within the Dao. The Dao will either commit or rollback the transaction and close the underlying Connection when complete.

Parameters:

item - The instance to be inserted.

Returns:

The newly issued primary key of the record.

atomicUpdate

void atomicUpdate(T item)

Run an update statement to change the values in the database associated with an existing record. Updates are applied by primary key. The update will occur within a transaction that is managed within the Dao. The Dao will either commit or rollback the transaction and close the underlying Connection when complete.

Parameters:

item - An instance of the class with a populated primary key field and updated field values.

atomicDelete

void atomicDelete(T item)

Run a delete statement in the database. Deletion is done by primary key. The delete will occur within a transaction that is managed within the Dao. The Dao will either commit or rollback the transaction and close the underlying Connection when complete.

Parameters:

item - An instance of type T with a populated primary key.